Asociación de trastornos cutáneos y microorganismos presentes en el tracto intestinal ligados a disbiosis / Association of skin disorders and microorganisms present in the intestinal tract linked to dysbiosis / Associação de doenças de pele e microrganismos presentes no trato intestinal ligados à disbiose

Introducción: Existe una conexión bidireccional entre mecanismos fisiológicos del intestino y la piel que puede asociarse al desarrollo de patologias cutâneas. Objetivo: estudiar la relación entre afecciones cutáneas con la presencia de patógenos intestinales causantes de disbiosis intestinal. Metodología: se realizó un estudio para identificar la presencia de bacterias aeróbicas y anaeróbicas facultativas en un grupo de 45 pacientes (edad de 32,8 ± 18 años) que presentaron distintas afecciones cutáneas diagnosticadas en la consulta de Dermatología de UNIMEL, Caracas, Venezuela. La presencia de bacterias se determinó por cultivo diferencial, y la identificación de microorganismos mediante pruebas bioquímicas convencionales, prueba de filamentización en suero, medios automatizados (VITEK® 2 Compact) y pruebas de aglutinación. Se realizó un análisis estadístico descriptivo de la abundancia relativa de la microbiota gastrointestinal asociada a las afecciones cutáneas presentes (GraphPad Prism versión 8.0.2 para Windows) y análisis multivariado (NMDS) con (software PAST v4.13). Resultados: la presencia de acné, dermatitis atópica y nevus se asoció (p<0.05) al aumento de las colonias de Enterococcus faecium, E. coli, Enteroccocus faecalis y Klepsiella sp. Una disminución significativa en el número de colonias de E. coli (p<0.05) se asoció con la presencia de rosácea y acné inflamatorio mientras que su abundancia se asoció a la presencia de patologías como acantosis nigicans, dermatitis atópica, dermatitis papular y queratosis. La presencia de pseudomonas se relacionó con queratosis y Nevus melanocítico. Conclusión: aunque preliminares, estos resultados sugieren que alteraciones en la composición microbiana intestinal pueden asociarse significativamente a afecciones cutáneas

Introduction: There is a bidirectional connection between physiological mechanisms of the intestine and the skin that can be associated with the development of skin pathologies. Objective: To study the relationship between skin conditions with the presence of intestinal pathogens that cause intestinal dysbiosis. Methodology: a study was carried out to identify the presence of aerobic and facultative anaerobic bacteria in a group of 45 patients (age 32.8 ± 18 years) who presented different skin conditions diagnosed in the Dermatology clinic of UNIMEL, Caracas, Venezuela. The presence of bacteria was determined by differential culture, and the identification of microorganisms by conventional biochemical tests, serum filamentation test, automated media (VITEK® 2 Compact) and agglutination tests. A descriptive statistical analysis of the relative abundance of the gastrointestinal microbiota associated with the present skin conditions was performed (GraphPad Prism version 8.0.2 for Windows) and multivariate analysis (NMDS) with (PAST v4.13 software). Results: the presence of acne, atopic dermatitis and nevus was associated (p<0.05) with the increase in colonies of Enterococcus faecium, E. coli, Enteroccocus faecalis and Klepsiella sp. A significant decrease in the number of E. coli colonies (p<0.05) was associated with the presence of rosacea and inflammatory acne while its abundance was associated with the presence of pathologies such as acanthosis nigicans, atopic dermatitis, papular dermatitis and keratosis. The presence of pseudomonas was related to keratosis and melanocytic nevus. Conclusion: although preliminary, these results suggest that alterations in intestinal microbial composition can be significantly associated with skin conditions.

Introdução: existe uma ligação bidirecional entre mecanismos fisiológicos do intestino e da pele que pode estar associada ao desenvolvimento de patologias cutâneas. Objetivo: estudar a relação entre as condições da pele com a presença de patógenos intestinais causadores de disbiose intestinal. Metodologia: foi realizado um estudo para identificar a presença de bactérias aeróbias e anaeróbias facultativas em um grupo de 45 pacientes (idade 32,8 ± 18 años) que apresentavam diferentes condições de pele diagnosticadas na clínica de Dermatologia da UNIMEL, Caracas, Venezuela. A presença de bactérias foi determinada por cultura diferencial, e a identificação de microrganismos por testes bioquímicos convencionais, teste de filamentação sérica, meios automatizados (VITEK® 2 Compact) e testes de aglutinação. Foi realizada análise estatística descritiva da abundância relativa da microbiota gastrointestinal associada às presentes condições de pele (GraphPad Prism versão 8.0.2 para Windows) e análise multivariada (NMDS) com (software PAST v4.13). Resultados: A presença de acne, dermatite atópica e nevo esteve associada (p<0,05) ao aumento de colônias de Enterococcus faecium, E. coli, Enteroccocus faecalis e Klepsiella sp. Uma diminuição significativa no número de colônias de E. coli (p<0,05) foi associada à presença de rosácea e acne inflamatória, enquanto sua abundância foi associada à presença de patologias como acantose nigicans, dermatite atópica, dermatite papular e ceratose. A presença de pseudomonas foi relacionada à ceratose e ao nevo melanocítico. Conclusão: embora preliminares, estes resultados sugerem que alterações na composição microbiana intestinal podem estar significativamente associadas a doenças da pele.

Asociación de trastornos cutáneos y microorganismos presentes en el tracto intestinal ligados a disbiosis

Introducción: Existe una conexión bidireccional entre mecanismos fisiológicos del intestino y la piel que puede asociarse al desarrollo de patologias cutâneas. Objetivo: Estudiar la relación entre afecciones cutáneas con la presencia de patógenos intestinales causantes de disbiosis intestinal. Metodología: Se realizó un estudio para identificar la presencia de bacterias aeróbicas y anaeróbicas facultativas en un grupo de 45 pacientes (edad de 32,8 ± 18 años) que presentaron distintas afecciones cutáneas diagnosticadas en la consulta de Dermatología de UNIMEL, Caracas, Venezuela. La presencia de bacterias se determinó por cultivo diferencial, y la identificación de microorganismos mediante pruebas bioquímicas convencionales, prueba de filamentización en suero, medios automatizados (VITEK® 2 Compact) y pruebas de aglutinación. Se realizó un análisis estadístico descriptivo de la abundancia relativa de la microbiota gastrointestinal asociada a las afecciones cutáneas presentes (GraphPad Prism versión 8.0.2 para Windows) y análisis multivariado (NMDS) con (software PAST v4.13). Resultados: La presencia de acné, dermatitis atópica y nevus se asoció (p<0.05) al aumento de las colonias de Enterococcus faecium, E. coli, Enteroccocus faecalis y Klepsiella sp. Una disminución significativa en el número de colonias de E. coli (p<0.05) se asoció con la presencia de rosácea y acné inflamatorio mientras que su abundancia se asoció a la presencia de patologías como acantosis nigicans, dermatitis atópica, dermatitis papular y queratosis. La presencia de pseudomonas se relacionó con queratosis y Nevus melanocítico. Conclusión: Aunque preliminares, estos resultados sugieren que alteraciones en la composición microbiana intestinal pueden asociarse significativamente a afecciones cutáneas.

Introduction: There is a bidirectional connection between physiological mechanisms of the intestine and the skin that can be associated with the development of skin pathologies. Objective: To study the relationship between skin conditions with the presence of intestinal pathogens that cause intestinal dysbiosis. Methodology: A study was carried out to identify the presence of aerobic and facultative anaerobic bacteria in a group of 45 patients (age 32.8 ± 18 years) who presented different skin conditions diagnosed in the Dermatology clinic of UNIMEL, Caracas, Venezuela. The presence of bacteria was determined by differential culture, and the identification of microorganisms by conventional biochemical tests, serum filamentation test, automated media (VITEK® 2 Compact) and agglutination tests. A descriptive statistical analysis of the relative abundance of the gastrointestinal microbiota associated with the present skin conditions was performed (GraphPad Prism version 8.0.2 for Windows) and multivariate analysis (NMDS) with (PAST v4.13 software). Results: The presence of acne, atopic dermatitis and nevus was associated (p<0.05) with the increase in colonies of Enterococcus faecium, E. coli, Enteroccocus faecalis and Klepsiella sp. A significant decrease in the number of E. coli colonies (p<0.05) was associated with the presence of rosacea and inflammatory acne while its abundance was associated with the presence of pathologies such as acanthosis nigicans, atopic dermatitis, papular dermatitis and keratosis. The presence of pseudomonas was related to keratosis and melanocytic nevus. Conclusion: Although preliminary, these results suggest that alterations in intestinal microbial composition can be significantly associated with skin conditions.

Introdução: Existe uma ligação bidirecional entre mecanismos fisiológicos do intestino e da pele que pode estar associada ao desenvolvimento de patologias cutâneas. Objetivo: Estudar a relação entre as condições da pele com a presença de patógenos intestinais causadores de disbiose intestinal. Metodologia: Foi realizado um estudo para identificar a presença de bactérias aeróbias e anaeróbias facultativas em um grupo de 45 pacientes (idade 32,8 ± 18 años) que apresentavam diferentes condições de pele diagnosticadas na clínica de Dermatologia da UNIMEL, Caracas, Venezuela. A presença de bactérias foi determinada por cultura diferencial, e a identificação de microrganismos por testes bioquímicos convencionais, teste de filamentação sérica, meios automatizados (VITEK® 2 Compact) e testes de aglutinação. Foi realizada análise estatística descritiva da abundância relativa da microbiota gastrointestinal associada às presentes condições de pele (GraphPad Prism versão 8.0.2 para Windows) e análise multivariada (NMDS) com (software PAST v4.13). Resultados: A presença de acne, dermatite atópica e nevo esteve associada (p<0,05) ao aumento de colônias de Enterococcus faecium, E. coli, Enteroccocus faecalis e Klepsiella sp. Uma diminuição significativa no número de colônias de E. coli (p<0,05) foi associada à presença de rosácea e acne inflamatória, enquanto sua abundância foi associada à presença de patologias como acantose nigicans, dermatite atópica, dermatite papular e ceratose. A presença de pseudomonas foi relacionada à ceratose e ao nevo melanocítico. Conclusão: Embora preliminares, estes resultados sugerem que alterações na composição microbiana intestinal podem estar significativamente associadas a doenças da pele.

Íleon terminal: aspecto a tener en cuenta en la COVID-19 ¿causa o efecto?

Introducción: la comprensión histomorfológica y biomolecular del íleon terminal; sitio clave en el control de la absorción nutricional, del metabolismo, sistema inmunitario, microbiota intestinal, y función de órganos extradigestivos; justifica su participación en los procesos inflamatorios intestinales, como pudiera ser en la infección por el SARS-CoV2. Objetivos: describir las evidencias biomoleculares de los componentes tisulares del íleon que justifican su función en el eje hepático-intestinal, y citar hallazgos histomorfológicos del íleon en fallecidos de la COVID-19. Adquisición de información: se realizó una revisión sistemática, crítica de los estudios biomoleculares sobre los enterocitos, la barrera epitelial intestinal, microbiota y permeabilidad intestinal del íleon que fundamentan su función de barrera epitelial, reportados en sitios Web (PubMed, Scielos, Lilacs, y Elservier), entre 2000 a 2021, y se citan hallazgos preliminares de cortes histomorfológicos del íleon en fallecidos de la COVID-19. Desarrollo se describen las evidencias biomoleculares del íleon normal, y la repercusión de su pérdida, disbiosis e hiperpermeabilidad en los procesos inflamatorios intestinales; también se citan hallazgos histomorfológicos preliminares de ileítis en fallecidos de la COVID-19, que pudiera fundamentar la importancia de la intuición biomolecular del íleon en el equilibrio salud-enfermedad, cuya pérdida justificaría el progreso clínico de la COVID-19. Conclusiones: la revisión integral del íleon y la cita de los hallazgos histomorfológicos preliminares de ileítis en fallecidos de la COVID-19, motiva realizar estudios amplios, que infieran su papel en el progreso clínico de la COVID-19 y justifique el futuro de nuevas intervenciones terapéuticas para su integridad.

Introduction terminal ileum, key site of control of nutritional absorption, metabolism, immune system, intestinal microbiota and extradigestive organ function. Histomorphological and biomolecular understanding of the ileum justifies its participation in intestinal inflammatory processes, such as SARS-CoV2 infection. Objective to describe the biomolecular evidence of the tissue components of the ileum that justifies its function in the hepatic-intestinal axis, and to cite histomorphological findings of the ileum in deaths from COVID-19. Information acquisition a systematic review was carried out, critical of reports between 2000 and 2021, on websites (PubMed, Scielos, Lilacs, and Elservier), of the biomolecular studies of the ileum (enterocytes, intestinal epithelial barrier, microbiota and intestinal permeability), which support its epithelial barrier function, and preliminary findings of histomorphological sections of the ileum in deaths from COVID-19 are cited. Development: biomolecular evidence of the normal ileum is described, and the repercussion of its loss, dysbiosis and hyperpermeability in intestinal inflammatory processes, and preliminary histomorphological findings of ileitis in deaths from COVID-19 are cited, which could substantiate the importance of the biomolecular intuition of the ileum in the health-disease balance, that its loss would justify the clinical progress of COVID-19. Conclusions: the comprehensive review of the ileum and the citation of the preliminary histomorphological findings of ileitis in deaths from COVID-19 motivates conducting extensive studies that infer its role in the clinical progress of COVID-19 and justify the future of new interventions. therapeutic for its integrity.

The impact of intestinal microbiota imbalance on the development of obesity / O impacto do desequilíbrio da microbiota intestinal no desenvolvimento da obesidade

Objective: review current databases to identify the impacts of intestinal dysbiosis on obesity, as well as serve as a pillar for carrying out preventive, diagnostic and therapeutic measures. Methodology: this is an integrative review carried out from the collection of data obtained from the SciELO, PubMed, VHL, and LILACS platforms using the descriptors "dysbiosis", "obesity" and "gastrointestinal microbiome"; Inclusion criteria were: articles published in the last five years (from 2017 to 2022), original articles, meta-analyses, and observational studies (clinical trials and cohort study) and written in Portuguese, English, or Spanish. Results: Western diet and use of sweeteners cause anthropometric changes, blood pressure, glucose intolerance, among others, in addition to leading to the prevalence of deleterious bacteria in the body, culminating in obesity and diabetes mellitus; on the other hand, a diet rich in fiber and administration of probiotics can generate beneficial changes in the diversity of the intestinal flora, in addition to combating the inflammatory state generated by obesity (AU).

Objetivo: revisar as bases de dados atuais para identificar os impactos da disbiose intestinal na obesidade, bem como servir de pilar para realização de medidas preventivas, diagnósticas e terapêuticas. Metodologia: trata-se de revisão integrativa realizada a partir de coleta de dados obtidos nas plataformas SciELO, PuBMed, BVS e LILACS usando os descritores "dysbiosis", "obesity" and "gastrointestinal microbiome"; os critérios de inclusão foram: artigos publicados nos últimos cinco anos (de 2017 a 2022), artigos originais, metanálises e estudos observacionais (ensaios clínicos e estudo de coorte) e escritos em português, inglês ou espanhol. Resultados: dieta ocidental e uso de adoçante provocam alterações antropométricas, de pressão arterial, intolerância à glicose, entre outras, além de levar à prevalência de bactérias deletérias ao organismo, culminando em obesidade e diabetes mellitus; em contrapartida, dieta rica em fibras e administração de probióticos podem gerar mudanças benéficas na diversidade da flora intestinal, ademais combatem o estado inflamatório gerado pela obesidade (AU).

The brain-gut-microbiota axis in the treatment of neurologic and psychiatric disorders / O eixo microbiota-intestino-cérebro no tratamento de desordens neurológicas e psiquiátricas

Abstract The human gut microbiota is a complex ecosystem made of trillions of microorganisms. The composition can be affected by diet, metabolism, age, geography, stress, seasons, temperature, sleep, and medications. The increasing evidence about the existence of a close and bi-directional correlation between the gut microbiota and the brain indicates that intestinal imbalance may play a vital role in the development, function, and disorders of the central nervous system. The mechanisms of interaction between the gut-microbiota on neuronal activity are widely discussed. Several potential pathways are involved with the brain-gut-microbiota axis, including the vagus nerve, endocrine, immune, and biochemical pathways. Gut dysbiosis has been linked to neurological disorders in different ways that involve activation of the hypothalamic-pituitary-adrenal axis, imbalance in neurotransmitter release, systemic inflammation, and increase in the permeability of the intestinal and the blood-brain barrier. Mental and neurological diseases have become more prevalent during the coronavirus disease 2019pandemic and are an essential issue in public health globally. Understanding the importance of diagnosing, preventing, and treating dysbiosis is critical because gut microbial imbalance is a significant risk factor for these disorders. This review summarizes evidence demonstrating the influence of gut dysbiosis on mental and neurological disorders.

Resumo A microbiota intestinal humana é um ecossistema complexo feito de trilhões de microrganismos, cuja composição pode ser afetada pela dieta, pelo metabolismo, pela idade, geografia, pelo estresse, pelas estações do ano, pela temperatura, pelo sono e por medicamentos. A crescente evidência sobre a existência de uma correlação estreita e bidirecional entre a microbiota intestinal e o cérebro indica que o desequilíbrio intestinal pode desempenhar um papel vital no desenvolvimento, na função e nos distúrbios do sistema nervoso central. Os mecanismos de interação entre a microbiota intestinal e a atividade neuronal são amplamente discutidos. Várias vias potenciais estão envolvidas com o eixo microbiota-intestino-cérebro, incluindo o nervo vago e as vias endócrinas, imunes e bioquímicas. A disbiose intestinal tem sido associada a distúrbios neurológicos de diferentes maneiras que envolvem a ativação do eixo hipotálamo-hipófise-adrenal, o desequilíbrio na liberação de neurotransmissores, a inflamação sistêmica e o aumento da permeabilidade das barreiras intestinal e hematoencefálica. As doenças mentais e neurológicas tornaram-se mais prevalentes durante a pandemia de coronavirus disease 2019 e são uma questão global essencial na saúde pública. Compreender a importância de diagnosticar, prevenir e tratar a disbiose é fundamental porque o desequilíbrio microbiano intestinal é um fator de risco significativo para esses distúrbios. Esta revisão resume as evidências que demonstram a influência da disbiose intestinal em distúrbios mentais e neurológicos.

Relação entre hábitos alimentares, peso corporal e saúde intestinal em indivíduos adultos / Relationship between eating habits, body weight, and intestinal health in adults

Introdução: A disbiose pode estar relacionada à hábitos alimentares ruins e alterações metabólicas que podem contribuir para o excesso de peso. Objetivo: Avaliar as escolhas alimentares que modulam a microbiota intestinal e a associação entre a saúde intestinal e o peso corporal de indivíduos adultos. Método: Estudo analítico, correlacional-descritivo e transversal realizado com 99 participantes, adultos, de ambos os sexos. Utilizou-se um Questionário Sociodemográfico e de Frequência Alimentar para coletar dados sociodemográficos, peso corporal, altura, frequência de consumo de alimentos fontes de prebióticos e probióticos e o Questionário de Rastreamento Metabólico (QRM), para investigar a saúde intestinal. O estudo ocorreu de forma online, via Google forms, sendo divulgado através das redes sociais (Facebook, Instagram, WhatsApp). Realizou-se uma análise descritiva dos dados e para associação entre variáveis empregou-se o teste Qui-quadrado de Pearson. Resultados: Do total de participantes, 74,7% eram mulheres. Quanto à classificação do Índice de Massa Corporal (IMC), 60,6% apresentaram eutrofia 24,2% sobrepeso e 9,1% algum grau de obesidade. Os alimentos fontes de probióticos e prebióticos mais consumidos foram queijo, iogurte, leites fermentados e banana, maçã, aveia, respectivamente. Porém, são alimentos que não fazem parte do consumo diário para a maioria dos participantes. Não houve diferença significativa entre a associação com IMC com sexo, escore final do QRM e somatório final dos sintomas gastrointestinais (p=0,76, p=0,29, p=0,70), respectivamente. Conclusão: Nota-se uma baixa frequência de consumo de alimentos que auxiliam na saúde intestinal. No entanto, não foi constatado que o peso corporal exerce influência na composição da microbiota intestinal.

Introducción: La disbiosis puede estar relacionada con malos hábitos alimentarios y alteraciones metabólicas que pueden contribuir al sobrepeso. Objetivo: Evaluar las elecciones alimentarias que modulan la microbiota intestinal y la asociación entre la salud intestinal y el peso corporal en personas adultas. Método: Estudio analítico, correlacional-descriptivo y transversal realizado con 99 personas participantes adultas de ambos sexos. Se utilizó un cuestionario sociodemográfico y de frecuencia alimentaria para recoger datos sociodemográficos, peso corporal, altura, frecuencia de consumo de fuentes alimentarias de prebióticos y probióticos y el Cuestionario de Seguimiento Metabólico para investigar la salud intestinal. El estudio se realizó online, a través de formularios de Google, siendo difundido a través de redes sociales (Facebook, Instagram, WhatsApp). Se realizó un análisis descriptivo de los datos y para la asociación entre variables se empleó el test Chi-cuadrado de Pearson. Resultados: Del total de participantes, el 74.7 % fueron mujeres. En cuanto a la clasificación del Índice de Masa Corporal, el 60.6 % eran personas eutróficas, el 24.2 % con sobrepeso y el 9.1% personas obesas. Los alimentos fuente de probióticos y prebióticos más consumidos fueron el queso, el yogur, las leches fermentadas, el plátano, la manzana y la avena. Sin embargo, se trata de alimentos que no forman parte del consumo diario de la mayoría de los participantes. No hubo diferencias significativas entre la asociación del Índice de Masa Corporal con el sexo, la puntuación final del Cuestionario de Seguimiento Metabólico y la suma final de síntomas gastrointestinales (p=0.76, p=0.29, p=0.70), respectivamente. Conclusiones: Se observa una baja frecuencia de consumo de alimentos que ayudan a la salud intestinal. Sin embargo, no se encontró que el peso corporal ejerza influencia sobre la composición de la microbiota intestinal.

Introduction: Dysbiosis may be related to poor eating habits and metabolic changes that can contribute to being overweight. Objective: To evaluate the food choices that modulate the gut microbiota and the association between gut health and body weight in adult individuals. Method: Analytical, correlational-descriptive, cross-sectional study conducted with 99 adult participants of both sexes. A Sociodemographic and Food Frequency Questionnaire was used to collect sociodemographic data, body weight, height, and frequency of consumption of food sources of prebiotics and probiotics; and the Metabolic Tracking Questionnaire was applied to investigate gut health. The study took place online, via Google Forms, and was disseminated through social media (Facebook, Instagram, WhatsApp). A descriptive analysis of the data was performed and for association between variables, the Pearson's Chi-square test was used. Results: Of the total number of participants, 74.7% were women. As for the classification of Body Mass Index, 60.6% were eutrophic, 24.2% were overweight, and 9.1% were somewhat obese. The most consumed probiotic and prebiotic food sources were cheese, yogurt, fermented kinds of milk; and banana, apple, and oatmeal, respectively. However, these are foods that are not part of the daily consumption for most participants. There was no significant difference between the association of the Body Mass Index with the sex of the participants or the final Metabolic Tracking Questionnaire score and the final sum of gastrointestinal symptoms (p=0.76, p=0.29, p=0.70). Conclusion: A low frequency of consumption of foods that aid intestinal health is noted. However, body weight was not found to influence the composition of the gut microbiota.

Effect of glyphosate and ciprofloxacin exposure on enteric bacteria of tadpoles / Efecto de la exposición a glifosato y ciprofloxacina en bacterias entéricasde renacuajos

Abstract The high load of agrochemicals and antibiotics present in agricultural aquatic environments represents a risk for wildlife. Since enteric bacteria, which play a key role in the physiological functioning of their hosts, are sensitive to a wide variety of pollutants, their study allows to evaluate the health of organisms. This study aimed to evaluate the effects of commercial formulations of a glyphosate-based herbicide (GBH) and the antibiotic ciprofloxacin (CIP), individually and in mixture, on the bacterial diversity of the intestinal content of common toad (Rhinella arenarum) tadpoles. The diversity of cultivable fast-growing bacteria with low nutritional requirements was evaluated using classic microbiological tests and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry identification. Bacterial diversity varied among treatments. Taxa diversity increased in the GBH-treated group but decreased in the CIP-treated group. Remarkably, Yersinia spp. and Proteus spp. were only found in the GBH-treated group. The prevalence of Klebsiella spp. and Pseudomonas spp. decreased in the intestinal microbiota of the GBH-CIP-treated group. To our knowledge, this is the first report on the alteration of cultivable enteric bacteria of autochthonous tadpoles due to two pollutants of emerging concern. Our results demonstrate that R. arenarum tadpoles can be used as non-conventional model organisms for environmental pollution monitoring. Our preliminary findings would contribute to understanding how the presence of GBH and CIP in freshwaters may represent a threat to wildlife and human health by causing enteric dysbiosis of part of the bacterial community.

Resumen La alta carga de agroquímicos y antibióticos en los ambientes acuáticos y los agroe-cosistemas representa un riesgo para la vida silvestre. Dado que la microbiota intestinal juega un papel fundamental en el funcionamiento de su hospedador y es sensible a una amplia variedad de contaminantes, su estudio permite evaluar la salud de los organismos. En este trabajo estudiamos los efectos de formulaciones comerciales de un herbicida a base de glifosato (GBH) y del antibiótico ciprofloxacina (CIP), por separado y en mezcla, sobre la diversidad de bacterias intestinales de renacuajos del sapo común (Rhinella arenarum). El estudio de la diversidad de bacterias entéricas cultivables de rápido crecimiento y bajo requerimiento nutricional se llevó a cabo utilizando pruebas microbiológicas clásicas e identificación por espectrometría de masas de tiempo de vuelo por desorción/ionización láser asistida por matriz (MALDI-TOF). La microbiota entérica fue diferente según el tratamiento. El GBH indujo un aumento de la diversidad bacteriana, mientras que la CIP produjo una reducción. Entre estos cambios, destaca la presencia de Yersinia spp. y Proteus spp. solo en el tratamiento con GBH. Además, en el tratamiento GBH-CIP se encontró una disminución en la prevalencia de Klebsiella spp. y Pseudomonas spp. en la microbiota intestinal de los renacuajos. Este es el primer informe sobre la alteración del contenido bacteriano intestinal de renacuajos de R. arenarum producido por dos contaminantes emergentes de preocupación. Demostramos que el renacuajo del sapo común se puede utilizar como un organismo modelo no convencional para el monitoreo de la contaminación ambiental. Estos hallazgos constituyen el primer paso para comprender cómo la presencia de GBH y CIP en aguas dulces puede representar una amenaza para la vida silvestre y la salud humana a través de la disbiosis entérica asociada al efecto sobre la comunidad bacteriana.

A Deep Insight into the Correlation Between Gut Dysbiosis and Alzheimer’s Amyloidopathy

Recent research has shown a strong correlation between gut dysbiosis and Alzheimer’s disease (AD). The purpose of this review is to investigate the relationship between gut dysbiosis, immune system activation, and the onset of AD and to examine current breakthroughs in microbiota-targeted AD therapeutics. A review of scientific literature was conducted to assess the correlation between gut dysbiosis and AD and the various factors associated. Gut dysbiosis produces an increase in harmful substances, such as bacterial amyloids, which makes the gut barrier and blood-brain barrier more permeable. This leads to the stimulation of immunological responses and an increase in cytokines such as interleukin-1? (IL-1?). As a result, gut dysbiosis accelerates the progression of AD. The review highlights the connection between gut dysbiosis and AD and the potential for microbiota-targeted therapies in AD treatment.

A doença de Alzheimer e sua relação com o eixo microbiota-intestino-cérebro / Alzheimer's disease and its relationship with the microbiota-gut-brain axis

ABSTRACT Background: Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disease, characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain. Several pathways enable bidirectional communication between the central nervous system (CNS), the intestine and its microbiota, constituting the microbiota-gut-brain axis. Objective: Review the pathophysiology of AD, relate it to the microbiota-gut-brain axis and discuss the possibility of using probiotics in the treatment and/or prevention of this disease. Methods: Search of articles from the PubMed database published in the last 5 years (2017 to 2022) structure the narrative review. Results: The composition of the gut microbiota influences the CNS, resulting in changes in host behavior and may be related to the development of neurodegenerative diseases. Some metabolites produced by the intestinal microbiota, such as trimethylamine N-oxide (TMAO), may be involved in the pathogenesis of AD, while other compounds produced by the microbiota during the fermentation of food in the intestine, such as D-glutamate and fatty acids short chain, are beneficial in cognitive function. The consumption of live microorganisms beneficial to health, known as probiotics, has been tested in laboratory animals and humans to evaluate the effect on AD. Conclusion: Although there are few clinical trials evaluating the effect of probiotic consumption in humans with AD, the results to date indicate a beneficial contribution of the use of probiotics in this disease.

RESUMO Contexto: A doença de Alzheimer (DA) é uma doença neurodegenerativa progressiva e irreversível, caracterizada pelo acúmulo de placas amiloides e emaranhados neurofibrilares no cérebro. Diversas vias possibilitam uma comunicação bidirecional entre o sistema nervoso central (SNC), o intestino e sua microbiota, constituindo o eixo microbiota-intestino-cérebro. Objetivo Revisar a fisiopatogenia da DA, relacioná-la com o eixo microbiota-intestino-cérebro e discutir sobre a possibilidade do uso de probióticos no tratamento e/ou prevenção desta doença. Métodos: Busca de artigos da base de dados PubMed publicados nos últimos 5 anos (2017 a 2022) para estruturar a revisão narrativa. Resultados A composição da microbiota intestinal influencia o SNC, resultando em modificações no comportamento do hospedeiro e pode estar relacionada com o desenvolvimento de doenças neurodegenerativas. Alguns metabólitos produzidos pela microbiota intestinal, como o N-óxido de trimetilamina (TMAO), podem estar envolvidos na patogênese da DA, enquanto, outros compostos produzidos pela microbiota durante a fermentação de alimentos no intestino, como o D-glutamato e os ácidos graxos de cadeia curta, são profícuos na função cognitiva. O consumo de microrganismos vivos benéficos à saúde, os probióticos, tem sido testado em animais de laboratório e humanos para avaliação do efeito na DA. Conclusão Embora haja poucos ensaios clínicos que avaliem o efeito do consumo de probióticos em humanos com DA, os resultados até o momento indicam uma contribuição benéfica do uso de probióticos nesta doença.

A short-term analysis of the modification process of the plaque microbial community before and after treatment in children with S-ECC / 口腔疾病防治

Objective @# To explore from the perspective of microorganisms the changes in plaque microbial community of children with severe early childhood caries (S-ECC) before and 3 months after dental treatment. Meanwhile to show the effect of treatment on the maintenance of long- term caries-free state. @*Methods@# S-ECC children completed dental treatment under general anesthesia. We collected plaque from caries-free dental surfaces before treatment (caries, C) and at the postoperative follow-up review time points of 7 days (C-7D), 1 month (C-1 M), and 3 months (C-3 M). We included caries-free children (caries free, CF) as the control group to analyze the dynamic modification process of the plaque microbial community in the short-term pre- and postdental treatment.@*Results@#Species clustering analysis showed that the compositions of the microbial communities of the S-ECC and CF groups were highly similar. The α diversity index was not statistically significant (P>0.05). From the analysis of the relative abundance, Leptotrichia spp. and Aggregatibacter spp. decreased after treatment compared with before treatment (P<0.05). Streptococcus sanguinis in the C-7D group increased compared with that in the C group and gradually decreased within 3 months. Veillonella spp., Actinomyces spp., Allprevotella spp., Capnocytophaga spp., and Streptococcus mutans differed between the C and CF groups (P<0.05), Streptococcus mutans did not differ significantly between the C-7D and C-1 M groups and the CF group after treatment, while C-3 M showed an increase compared with the CF group (P<0.01). @*Conclusion@#The rapid change in the structure of the flora of children with S-ECC after treatment. The plaque microbial community structure in a caries-free state gradually starts to be established 1-3 months after treatment. There is a "core microbiota" in the oral plaque community that jointly maintains microecological stability. Veillonella spp., Allprevotella spp. and Streptococcus mutans have potential as possible microbial markers.

Theoretical basis and progress of fecal microbiota transplantation in metabolic associated fatty liver disease / 中华临床营养杂志

Metabolic associated fatty liver disease (MAFLD) is a cluster of chronic, progressive diseases with an increasing prevalence rate worldwide. MAFLD has become the leading cause of chronic liver disease around the world, for which approved therapy is currently lacking. In recent years, growing evidence has demonstrated the close link between gut microbiome dysbiosis and MAFLD. The generation of pro-inflammatory bacterial components and metabolites is susceptible to the changes in the abundance, diversity, and ratio of intestinal bacteria, which could accelerate the progress of MAFLD through the gut-liver axis. As a new therapeutic strategy, fecal microbiota transplantation (FMT) is the transplantation of flora from the intestines of healthy people into the gastrointestinal tract of patients, to directly correct intestinal flora disorders and alter bacterial metabolites. FMT has been widely used in the treatment of Clostridium difficile infections and inflammatory bowel disease. The role of FMT in the treatment of MAFLD has also been explored. However, studies about FMT in MAFLD are overall scarce and the mechanism of action and the therapeutic effect of FMT on MAFLD remains ambiguous. We summarized the existing evidence on the potential molecular mechanism and effectiveness related to FMT in MAFLD.

Alterations of gut microbiota composition and cogni-tive behavior in APP/PS1/tau triple-transgenic mouse model of Alzheimer's disease / 中国药理学与毒理学杂志

OBJECTIVE Alzheimer's disease(AD)is a progressive neurological disease.Given the important role of gut microbiota composition in AD pathology,the observed perturbation in the microbiota composition and diversity may serve as the mechanisms underlying age-dependent APP/PS1/tau triple-transgenic mouse(3×Tg-AD)mice amyloid deposition and memory deficits.Here-in,we intended to investigate the gut microbiota and as-sessed its relationship with the triggering and develop-ment of cognitive impairment of AD.METHODS This study involves the comparative assessment of spatial learning,amyloid β-protein(Aβ)accumulation,and fecal microbiota alterations in 3×Tg-AD mice from three age groups:AD asymptomatic stage(3 m),presymptomatic stage(6 m),and the symptomatic stage of AD(9 m).RE-SULTS We demonstrate that spatial memory deficits,brain Aβ accumulation,and weight gain in 3×Tg-AD mice gradually appear after 6 months of age.However,the total gut bacterial counts underwent changes from 3 to 6 months of age and were further altered at 9 months of age.Importantly,changes in gut bacteria abundance of Desulfobacterota and Actinobacteriota phylain 6-month-old mice preceded apparent spatial memory deficits.CONCLUSION Changes in the gut microbial community are one of the mechanisms of early AD pathology.

Progress in the relationship between intestinal fungal dysbiosis and digestive system tumors / 中华微生物学和免疫学杂志

Intestinal fungal dysbiosis is closely associated with the development and progression of many diseases including tumors. The disruption of fungal communities is involved in tumorigenesis and progression through inducing aberrant host immune responses and the production of certain metabolites as well as promoting the establishment of interactions with bacteria. Fungal dysbiosis is a potential marker for early detection of digestive tumors and a factor influencing the efficacy of tumor therapy. Studying the association between gut fungi and digestive tumors may facilitate the prevention, diagnosis and treatment of digestive tumors.

Research progress of human surface microbiota and ocular surface diseases / 国际眼科杂志(Guoji Yanke Zazhi)

The ocular surface microbiota is a part of the human ocular surface microenvironment and is critical to its stability. Many studies have explored the composition of the ocular surface microbiota in health and disease, but the research results are different based on internal and external factors, and the relationship between microorganism dysbiosis and diseases also remains unclear. As the research on intestinal microorganisms and systemic diseases has intensified in recent years, ophthalmic researchers have been inspired to further explore the relationship between ocular surface microbiota and non-infectious ocular surface diseases. Therefore, this article will review the core microbiota of the normal ocular surface as well as alterations in ocular surface microbiota in ocular and systemic diseases, and discuss the possible mechanisms of diseases caused by microorganism dysbiosis, hoping to provide a reference for future studies in ocular surface microbiota.

Gut dysbiosis aggravates cognitive deficits,amyloid pathology and lipid metabolism dysregulation in a transgenic mouse model of Alzheimer's disease / 药物分析学报

Gut dysbiosis,a well-known risk factor to triggers the progression of Alzheimer's disease(AD),is strongly associated with metabolic disturbance.Trimethylamine N-oxide(TMAO),produced in the dietary choline metabolism,has been found to accelerate neurodegeneration in AD pathology.In this study,the cognitive function and gut microbiota of TgCRND8(Tg)mice of different ages were evaluated by Morris water maze task(MWMT)and 16S rRNA sequencing,respectively.Young pseudo germ-free(PGF)Tg mice that received faecal microbiota transplants from aged Tg mice and wild-type(WT)mice were selected to determine the role of the gut microbiota in the process of neuropathology.Excessive choline treatment for Tg mice was used to investigate the role of abnormal choline metabolism on the cognitive functions.Our results showed that gut dysbiosis,neuroinflammation response,Aβ deposition,tau hyper-phosphorylation,TMAO overproduction and cyclin-dependent kinase 5(CDK5)/transcription 3(STAT3)activation occurred in Tg mice age-dependently.Disordered microbiota of aged Tg mice accelerated AD pathology in young Tg mice,with the activation of CDK5/STAT3 signaling in the brains.On the contrary,faecal microbiota transplantation from WT mice alleviated the cognitive deficits,attenuated neuro-inflammation,Aβ deposition,tau hyperphosphorylation,TMAO overproduction and suppressed CDK5/STAT3 pathway activation in Tg mice.Moreover,excessive choline treatment was also shown to aggravate the cognitive deficits,Aβ deposition,neuroinflammation and CDK5/STAT3 pathway activation.These findings provide a novel insight into the interaction between gut dysbiosis and AD progression,clarifying the important roles of gut microbiota-derived substances such as TMAO in AD neuropathology.

Impact of gut-peripheral nervous system axis on the development of diabetic neuropathy

Diabetes is a chronic metabolic disease caused by a reduction in the production and/or action of insulin, with consequent development of hyperglycemia. Diabetic patients, especially those who develop neuropathy, presented dysbiosis, with an increase in the proportion of pathogenic bacteria and a decrease in the butyrate-producing bacteria. Due to this dysbiosis, diabetic patients presented a weakness of the intestinal permeability barrier and high bacterial product translocation to the bloodstream, in parallel to a high circulating levels of pro-inflammatory cytokines such as TNF-α. In this context, we propose here that dysbiosis-induced increased systemic levels of bacterial products, like lipopolysaccharide (LPS), leads to an increase in the production of pro-inflammatory cytokines, including TNF-α, by Schwann cells and spinal cord of diabetics, being crucial for the development of neuropathy.

Alteración de la microbiota intestinal y su relación con enfermedades gastrointestinales y hepatobiliares / Disruption of the intestinal microbiota and its relationship with gastrointestinal and hepatobiliary diseases

La interrupción de la simbiosis que existe entre el cuerpo humano y su microbioma puede resultar en una disbiosis, un desequilibrio en la interacción huésped-microbiota, que puede asociarse al desarrollo de diversas enfermedades como el síndrome de intestino irritable, hígado graso no alco-hólico, enfermedad hepática alcohólica y cirrosis, entre otras. En ciertas condiciones patológicas y por múltiples factores de riesgo, la capacidad de autorregulación del intestino se puede alterar, contribuyendo al incremento de la permeabilidad con inflamación intestinal crónica. El diagnóstico y el tratamiento, así como la relación entre la permeabilidad intestinal, la disbiosis y las patologías gastrointestinales y hepatobiliares, todavía no tienen estudios clínicos validados o con el soporte científico adecuado, por lo que se realiza una revisión de la literatura con la finalidad de aportar conceptos que puedan orientar con respecto a la importancia del estudio del microbioma humano en estas enfermedades.

Disruption of the symbiosis that exists between the human body and its microbiome can result in dys-biosis, an imbalance in the host-microbiota interaction, which may be associated with the develop-ment of various diseases such as irritable bowel syndrome, non-alcoholic fatty liver disease, alcoholic liver disease and cirrhosis, among others. In certain pathological conditions and due to multiple risk factors, the self-regulating capacity of the intestine may be lost, contributing to increased permeability with chronic intestinal inflammation. Its diagnosis and treatment as well as the relationship between intestinal permeability, dysbiosis and gastrointestinal and hepatobiliary pathologies have not been validated in clinical studies or have adequate scientific support, so a review of the literature is carried out in order to provide concepts that can guide with respect to the importance of the study of the human microbiome in these diseases

Fisiopatología de la programación fetal y su repercusión en la salud futura / Pathophysiology of fetal programming and its impact on the future health

Resumen ANTECEDENTES: Durante la vida intrauterina, las alteraciones en el microambiente fetal causadas por desequilibrios nutricionales y metabólicos de la madre pueden dejar huellas epigenéticas y efectos persistentes en la vida adulta de su hijo que habrán de predisponerlo a enfermedades crónicas futuras. OBJETIVO: Llevar a cabo una revisión sistemática de la fisiopatología de la programación fetal y su repercusión en la salud futura del feto. METODOLOGÍA: Búsqueda en la base de datos de PubMed de artículos publicados, en los últimos 10 años, en inglés o español, con los MeSH "fetal programming"; "pathophysiology", con su correspondiente traducción. Se incluyeron artículos originales y de revisión con criterios PRISMA para revisiones sistemáticas. RESULTADOS: Se encontraron 38 artículos, y se agregaron 7 de información complementaria y sustento para la discusión. En su análisis queda clara la relación entre las condiciones fisiopatológicas reportadas de desnutrición, sub y sobrealimentación, diabetes mellitus gestacional, obesidad, resistencia a la insulina, glucocorticoides y preeclampsia con enfermedades de la infancia, adolescencia y adultez. Se encontró evidencia de disruptores endocrinos, melatonina y disbiosis con enfermedades de la infancia y vida adulta. Así mismo, la interrupción de la angiogénesis durante el desarrollo pulmonar que conduce a hipertensión arterial pulmonar y enfisema, todo ello originado por la programación fetal epigenética. Se encontraron diferencias en el patrón de metilación de placentas prematuras en comparación con las de término. CONCLUSIONES: Las anormalidades que sobrevienen durante el embarazo modifican la programación fetal y dan pie a las enfermedades que aparecerán durante la infancia, adolescencia y adultez, como consecuencia de los cambios en el patrón de metilación de los genes.

Abstract BACKGROUND: During intrauterine life, alterations in the fetal microenvironment caused by maternal nutritional and metabolic imbalances may leave epigenetic imprints and persistent effects on fetal adult life that will predispose the fetus to future chronic diseases. OBJECTIVE: To carry out a systematic review of the pathophysiology of fetal programming and its impact on the future health of the fetus. METHODOLOGY: Search in the PubMed database of articles published in the last 10 years, in English or Spanish, with the MeSH "fetal programming"; "pathophysiology", with their corresponding translation. Original and review articles with PRISMA criteria for systematic reviews were included. RESULTS: Thirty-eight articles were found, and seven were added for complementary information and support for discussion. In their analysis the relationship between the reported pathophysiological conditions of under-, under- and over-nutrition, gestational diabetes mellitus, obesity, insulin resistance, glucocorticoids and pre-eclampsia with diseases of childhood, adolescence and adulthood is clear. Evidence of endocrine disruptors, melatonin and dysbiosis was found with diseases of childhood and adulthood. Also, disruption of angiogenesis during lung development leads to pulmonary arterial hypertension and emphysema, all caused by epigenetic fetal programming. Differences were found in the methylation pattern of preterm placentas compared to term placentas. CONCLUSIONS: Abnormalities that occur during pregnancy modify fetal programming and give rise to the diseases that will appear during childhood, adolescence, and adulthood, because of changes in the methylation pattern of genes.

In sickness and in health: the intestinal microbiome of dogs / Na saúde e na doença: os efeitos do microbioma intestinal no cão

Studies on the interactions between the intestinal microbiome and its host have strengthened in the last decade. However, publications on this topic in dogs still need to be made available, reinforcing the need for new studies and literary data for consultation. Given this, this review aims to describe the intestinal microbiome and its interactions with the canine host, which can contribute to both health and morbid conditions in these animals. The definition of microbiome encompasses the collective genome of all microorganisms that live in a defined habitat (intestine). It is known that the dog's intestinal microbiota is varied, composed of bacteria, archaea, viruses, fungi, and protozoa. Under normal conditions, there is commensalism between some of these microorganisms and the host, which promotes critical physiological relationships and interactions that contribute to homeostasis and the consequent health of the animal. With this in mind, it is expected that the disturbances associated with the microbiome will result in imbalances in this commensal relationship and thus precipitate the development of diseases and aggravation of other diseases, thus characterizing intestinal dysbiosis.(AU)

Os estudos sobre as interações entre o microbioma intestinal e o seu hospedeiro ganharam força na última década. Entretanto, as publicações acerca de tal temática em cães ainda são escassas, o que reforça a necessidade de novos estudos e dados literários para consultas. Frente a isso, o objetivo da presente revisão é descrever sobre o microbioma intestinal e suas interações e principais efeitos no cão, os quais podem contribuir tanto para a higidez quanto para quadros mórbidos desses animais. A definição de microbioma engloba o genoma coletivo de todos os microrganismos que vivem em habitat definido (intestino). É sabido que a microbiota intestinal do cão é muito variada, sendo composta por bactérias, arqueas, vírus, fungos e protozoários. Em condições normais, há o comensalismo entre alguns desses microrganismos e o hospedeiro, o que promove importantes relações e interações fisiológicas que contribuem sobremaneira para a homeostasia e consequente saúde do animal. Ciente disso, é de se esperar que os distúrbios associados ao microbioma resultarão em desequilíbrios nessa relação comensal e, assim, precipitar o desenvolvimento de doenças e/ou agravamento de outras moléstias, caracterizando, assim, a disbiose intestinal.(AU)

O impacto da pandemia da covid-19 na microbiota intestinal do lactente / The impact of the covid-19 pandemic on the infant gut microbiota / El impacto de la pandemia de covid-19 en la microbiota intestinal del lactante

A COVID-19 resultou em milhares de óbitos e até o presente momento assola diversos pacientes com as suas implicações. Uma das consequências da doença foi o isolamento social, realizado por quase todos os países, o que configurou a alteração de diversos padrões de convivência e principalmente de exposição a outros agentes não patogênicos e patogênicos essenciais para o desenvolvimento da microbiota. Com isso, o seguinte projeto tem como objetivo a descrição dos impactos da pandemia da COVID-19 na microbiota intestinal de lactentes do período pandêmico e as consequências geradas no sistema imunológico imaturo, prejudicando seu desenvolvimento e maturação. A metodologia consiste na análise e seleção de artigos científicos publicados nos últimos 10 anos com auxílio de Descritores em Ciências da Saúde (DeCS) específicos nas línguas inglesa e portuguesa para o tema da pesquisa, sendo a combinação dos descritores feita por meio de operadores booleanos. Conclui-se que a composição da microbiota intestinal é iniciada intraútero e influenciada pela via de parto, contato pele a pele após o nascimento e pela presença da amamentação materna. A modificação das práticas durante a pandemia da COVID-19, pode alterar a microbiologia neonatal, assim como impactar na maturação do sistema imunológico do lactente, predispondo futuramente à doenças gastrointestinais, metabólicas e atópicas, como asma.

COVID-19 has resulted in thousands of deaths and until now is affecting many patients with its implications. One of the consequences of the disease was social isolation, carried out by almost all countries, which resulted in changes in different patterns of coexistence and mainly exposure to other non-pathogenic and pathogenic agents essential for the development of the microbiota. Therefore, the following project aims to describe the impacts of the COVID-19 pandemic on the microbiota of infants during the pandemic period and the consequences generated on the immature immune system, damaging its development and maturation and relating microbiology, essentially intestinal, throughout the project. The methodology consists of the analysis and selection of scientific articles published in the last 10 years with the help of specific Health Sciences Descriptors in English and Portuguese for the research topic, with the combination of descriptors made using Boolean operators. It is concluded that the composition of the intestinal microbiota begins in utero and is influenced by the mode of delivery, skin-to- skin contact after birth, and the presence of maternal breastfeeding. Modifying practices during the COVID-19 pandemic may alter neonatal microbiology and impact the maturation of the infant's immune system, potentially predisposing them to future gastrointestinal, metabolic, and atopic diseases such as asthma.

El COVID-19 ha provocado miles de muertes y todavía afecta a muchos pacientes con sus implicaciones. Una de las consecuencias de la enfermedad fue el aislamiento social, llevado a cabo por casi todos los países, que resultó en cambios en diferentes patrones de convivencia y principalmente exposición a otros agentes patógenos y no patógenos esenciales para el desarrollo de la microbiota. Com eso, el siguiente proyecto tiene como objetivo describir los impactos de la pandemia de COVID-19 en la microbiota de los lactantes durante el periodo pandémico y las consecuencias generadas sobre el sistema inmunológico inmaduro, perjudicando su desarrollo y maduración y relacionando la microbiología, fundamentalmente intestinal, a lo largo del proyecto. La metodología consiste en el análisis y selección de artículos científicos publicados en los últimos 10 años con la ayuda de Descriptores en Ciencias de la Salud específicos en inglés y portugués para el tema de investigación, con la combinación de descriptores realizada mediante operadores booleanos. Se concluye que la composición de la microbiota intestinal comienza intraútero y está influenciada por la vía de parto, el contacto piel a piel después del nacimiento y la presencia de la lactancia materna. La modificación de las prácticas durante la pandemia de COVID-19 puede alterar la microbiología neonatal y afectar la maduración del sistema inmunológico del lactante, predisponiéndolo potencialmente a enfermedades gastrointestinales, metabólicas y atópicas en el futuro, como la asma.