Is Nasal Dysbiosis a Required Component for Neuroinflammation in Major Depressive Disorder?

Human microbiota is known to influence immune and cerebral responses by direct and/or indirect mechanisms, including hypothalamic-pituitary-adrenal axis signaling, activation of neural afferent circuits to the brain, and by altering the peripheral immune responses (cellular and humoral immune function, circulatory inflammatory cells, and the production of several inflammatory mediators, such as cytokines, chemokines, and reactive oxygen species). The inflammatory responses in the nasal mucosa (rhinitis) or paranasal sinuses (chronic rhinosinusitis) are dual conditions related with a greater risk for developing depression. In the nasal cavity, anatomic components of the olfactive function are in direct contact with the CNS through the olfactory receptors, neurons, and axons that end in the olfactory bulb and the entorhinal cortex. Local microbiome alterations (dysbiosis) are linked to transepithelial translocation of microorganisms and their metabolites, which disrupts the epithelial barrier and favors vascular permeability, increasing the levels of several inflammatory molecules (both cytokines and non-cytokine mediators: extracellular vesicles (exosomes) and neuropeptides), triggering local inflammation (rhinitis) and the spread of these components into the central nervous system (neuroinflammation). In this review, we discuss the role of microbiota-related immunity in conditions affecting the nasal mucosa (chronic rhinosinusitis and allergic rhinitis) and their relevance in major depressive disorders, focusing on the few mechanisms known to be involved and providing some hypothetical proposals on the pathophysiology of depression.

Engineering a dysbiotic biofilm model for testing root caries interventions through microbial modulation.

BACKGROUND: This study aimed to engineer and optimise a dysbiotic biofilm model to develop in vitro root caries for investigating microbial modulation strategies. The model involved growing complex biofilms from a saliva inoculum collected from four volunteers using two strategies. In the first strategy ("pre-treatment strategy"), bovine root slabs were used, and two natural compounds were incorporated at time 0 of the 10-day biofilm experiment, which included sucrose cycles mimicking the cariogenic environment. In the second strategy ("post-treatment strategy"), mature biofilms were grown in a modified Calgary biofilm device coated with collagen and hydroxyapatite for 7 days and then were exposed to the same natural compounds. The metatranscriptome of each biofilm was then determined and analysed. Collagenase activity was examined, and the biofilms and dentine were imaged using confocal and scanning electron microscopy (SEM). Mineral loss and lesion formation were confirmed through micro-computed tomography (µ-CT). RESULTS: The pH confirmed the cariogenic condition. In the metatranscriptome, we achieved a biofilm compositional complexity, showing a great diversity of the metabolically active microbiome in both pre- and post-treatment strategies, including reads mapped to microorganisms other than bacteria, such as archaea and viruses. Carbohydrate esterases had increased expression in the post-treated biofilms and in samples without sugar cycles, while glucosyltransferases were highly expressed in the presence of sucrose cycles. Enrichment for functions related to nitrogen compound metabolism and organic cyclic component metabolism in groups without sucrose compared to the sucrose-treated group. Pre-treatment of the roots with cranberry reduced microbial viability and gelatinase (but not collagenase) activity (p < 0.05). SEM images showed the complexity of biofilms was maintained, with a thick extracellular polysaccharides layer. CONCLUSIONS: This root caries model was optimized to produce complex cariogenic biofilms and root caries-like lesions, and could be used to test microbial modulation in vitro. Pre-treatments before biofilm development and cariogenic challenges were more effective than post-treatments. The clinical significance lies in the potential to apply the findings to develop varnish products for post-professional tooth prophylaxis, aiming at implementing a strategy for dysbiosis reversal in translational research. Video Abstract.

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.

Environmental Enrichment Prevents Gut Dysbiosis Progression and Enhances Glucose Metabolism in High-Fat Diet-Induced Obese Mice.

Obesity is a global health concern implicated in numerous chronic degenerative diseases, including type 2 diabetes, dyslipidemia, and neurodegenerative disorders. It is characterized by chronic low-grade inflammation, gut microbiota dysbiosis, insulin resistance, glucose intolerance, and lipid metabolism disturbances. Here, we investigated the therapeutic potential of environmental enrichment (EE) to prevent the progression of gut dysbiosis in mice with high-fat diet (HFD)-induced metabolic syndrome. C57BL/6 male mice with obesity and metabolic syndrome, continuously fed with an HFD, were exposed to EE. We analyzed the gut microbiota of the mice by sequencing the 16s rRNA gene at different intervals, including on day 0 and 12 and 24 weeks after EE exposure. Fasting glucose levels, glucose tolerance, insulin resistance, food intake, weight gain, lipid profile, hepatic steatosis, and inflammatory mediators were evaluated in serum, adipose tissue, and the colon. We demonstrate that EE intervention prevents the progression of HFD-induced dysbiosis, reducing taxa associated with metabolic syndrome (Tepidimicrobium, Acidaminobacteraceae, and Fusibacter) while promoting those linked to healthy physiology (Syntrophococcus sucrumutans, Dehalobacterium, Prevotella, and Butyricimonas). Furthermore, EE enhances intestinal barrier integrity, increases mucin-producing goblet cell population, and upregulates Muc2 expression in the colon. These alterations correlate with reduced systemic lipopolysaccharide levels and attenuated colon inflammation, resulting in normalized glucose metabolism, diminished adipose tissue inflammation, reduced liver steatosis, improved lipid profiles, and a significant reduction in body weight gain despite mice's continued HFD consumption. Our findings highlight EE as a promising anti-inflammatory strategy for managing obesity-related metabolic dysregulation and suggest its potential in developing probiotics targeting EE-modulated microbial taxa.

The connection between gut microbiota and its metabolites with neurodegenerative diseases in humans.

The aging of populations is a global phenomenon that follows a possible increase in the incidence of neurodegenerative diseases. Alzheimer's, Parkinson's, Multiple Sclerosis, Amyotrophic Lateral Sclerosis, and Huntington's diseases are some neurodegenerative disorders that aging could initiate or aggravate. Recent research has indicated that intestinal microbiota dysbiosis can trigger metabolism and brain functioning, contributing to the etiopathogenesis of those neurodegenerative diseases. The intestinal microbiota and its metabolites show significant functions in various aspects, such as the immune system modulation (development and maturation), the maintenance of the intestinal barrier integrity, the modulation of neuromuscular functions in the intestine, and the facilitation of essential metabolic processes for both the microbiota and humans. The primary evidence supporting the connection between intestinal microbiota and its metabolites with neurodegenerative diseases are epidemiological observations and animal models experimentation. This paper reviews up-to-date evidence on the correlation between the microbiota-gut-brain axis and neurodegenerative diseases, with a specially focus on gut metabolites. Dysbiosis can increase inflammatory cytokines and bacterial metabolites, altering intestinal and blood-brain barrier permeability and causing neuroinflammation, thus facilitating the pathogenesis of neurodegenerative diseases. Clinical data supporting this evidence still needs to be improved. Most of the works found are descriptive and associated with the presence of phyla or species of bacteria with neurodegenerative diseases. Despite the limitations of recent research, the potential for elucidating clinical questions that have thus far eluded clarification within prevailing pathophysiological frameworks of health and disease is promising through investigation of the interplay between the host and microbiota.

Vitamin D3 supplementation in COVID-19 patients with cardiovascular disease and gut dysbiosis.

BACKGROUND: The COVID-19 pandemic has highlighted the vulnerability of particular patient groups to SARS-CoV-2 infection, including those with cardiovascular diseases, hypertension, and intestinal dysbiosis. COVID-19 affects the gut, suggesting diet and vitamin D3 supplementation may affect disease progression. AIMS: To evaluate levels of Ang II and Ang-(1-7), cytokine profile, and gut microbiota status in patients hospitalized for mild COVID-19 with a history of cardiovascular disease and treated with daily doses of vitamin D3. METHODS: We recruited 50 adult patients. We screened 50 adult patients and accessed pathophysiology study 22, randomized to daily oral doses of 10,000IU vitamin D3 (n=11) or placebo (n=11). Plasma levels of Ang II and Ang-(1-7) were determined by radioimmunoassay, TMA and TMAO were measured by liquid chromatography and interleukins (ILs) 6, 8, 10 and TNF-α by ELISA. RESULTS: The Ang-(1-7)/Ang II ratio, as an indirect measure of ACE2 enzymatic activity, increased in the vitamin D3 group (24±5pg/mL vs. 4.66±2pg/mL, p<0.01). Also, in the vitamin D3-treated, there was a significant decline in inflammatory ILs and an increase in protective markers, such as a substantial reduction in TMAO (5±2µmoles/dL vs. 60±10µmoles/dL, p<0.01). In addition, treated patients experienced less severity of infection, required less intensive care, had fewer days of hospitalization, and a reduced mortality rate. Additionally, improvements in markers of cardiovascular function were seen in the vitamin D3 group, including a tendency for reductions in blood pressure in hypertensive patients. CONCLUSIONS: Vitamin D3 supplementation in patients with COVID-19 and specific conditions is associated with a more favourable prognosis, suggesting therapeutic potential in patients with comorbidities such as cardiovascular disease and gut dysbiosis.

COVID-19 in a common woolly monkey (Lagothrix lagothricha): First evidence of fatal outcome in a nonhuman primate after natural SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic by the World Health Organization in March 2020. Since then, viral spread from humans to animals has occurred worldwide. Nonhuman primates (NHPs) have been found to be susceptible to reverse-zoonosis transmission of SARS-CoV-2, but initial research suggested that platyrrhine primates are less susceptible than catarrhine primates. Here we report the natural SARS-CoV-2 infection of a common woolly monkey (Lagothrix lagothricha) from a wildlife rehabilitation center in Ecuador. The course of the disease, the eventual death of the specimen, and the pathological findings are described. Our results show the susceptibility of a new platyrrhine species to SARS-CoV-2 and provide evidence for the first time of a COVID-19-associated death in a naturally infected NHP. The putative route of transmission from humans, and implications for captive NHPs management, are also discussed. Given that common woolly monkeys are at risk of extinction in Ecuador, further understanding of the potential threat of SARS-CoV-2 to their health should be a conservation priority. A One Health approach is the best way to protect NHPs from a new virus in the same way that we would protect the human population.

Comprehensive Analysis of Gut Microbiota Composition and Functional Metabolism in Children with Autism Spectrum Disorder and Neurotypical Children: Implications for Sex-Based Differences and Metabolic Dysregulation.

This study aimed to investigate the gut microbiota composition in children with autism spectrum disorder (ASD) compared to neurotypical (NT) children, with a focus on identifying potential differences in gut bacteria between these groups. The microbiota was analyzed through the massive sequencing of region V3-V4 of the 16S RNA gene, utilizing DNA extracted from stool samples of participants. Our findings revealed no significant differences in the dominant bacterial phyla (Firmicutes, Bacteroidota, Actinobacteria, Proteobacteria, Verrucomicrobiota) between the ASD and NT groups. However, at the genus level, notable disparities were observed in the abundance of Blautia, Prevotella, Clostridium XI, and Clostridium XVIII, all of which have been previously associated with ASD. Furthermore, a sex-based analysis unveiled additional discrepancies in gut microbiota composition. Specifically, three genera (Megamonas, Oscilibacter, Acidaminococcus) exhibited variations between male and female groups in both ASD and NT cohorts. Particularly noteworthy was the exclusive presence of Megamonas in females with ASD. Analysis of predicted metabolic pathways suggested an enrichment of pathways related to amine and polyamine degradation, as well as amino acid degradation in the ASD group. Conversely, pathways implicated in carbohydrate biosynthesis, degradation, and fermentation were found to be underrepresented. Despite the limitations of our study, including a relatively small sample size (30 ASD and 31 NT children) and the utilization of predicted metabolic pathways derived from 16S RNA gene analysis rather than metagenome sequencing, our findings contribute to the growing body of evidence suggesting a potential association between gut microbiota composition and ASD. Future research endeavors should focus on validating these findings with larger sample sizes and exploring the functional significance of these microbial differences in ASD. Additionally, there is a critical need for further investigations to elucidate sex differences in gut microbiota composition and their potential implications for ASD pathology and treatment.

Probiotics as a strategy for addressing helminth infections in low-income countries: Working smarter rather than richer.

Helminth infections, which affect approximately 1.5 billion individuals worldwide (mainly children), are common in low- and middle-income tropical countries and can lead to various diseases. One crucial factor affecting the occurrence of these diseases is the reduced diversity of the gut microbiome due to antibiotic use. This reduced diversity compromises immune health in hosts and alters host gene expression through epigenetic mechanisms. Helminth infections may produce complex biochemical signatures that could serve as therapeutic targets. Such therapies include next-generation probiotics, live biotherapeutic products, and biochemical drug approaches. Probiotics can bind ferric hydroxide, reducing the iron that is available to opportunistic microorganisms. They also produce short-chain fatty acids associated with immune response modulation, oral tolerance facilitation, and inflammation reduction. In this review, we examine the potential link between these effects and epigenetic changes in immune response-related genes by analyzing methyltransferase-related genes within probiotic strains discussed in the literature. The identified genes were only correlated with methylation in bacterial genes. Various metabolic interactions among hosts, helminth parasites, and intestinal microbiomes can impact the immune system, potentially aiding or hindering worm expulsion through chemical signaling. Implementing a comprehensive strategy using probiotics may reduce the impact of drug-resistant helminth strains.

Streptococcus dentisani inhibits the growth of Candida albicans and Candida glabrata: in vitro assay.

BACKGROUND: Probiotic bacteria inhibit aggregation, biofilm formation, and dimorphism of Candida spp. However, the effects of a new probiotic, Streptococcus dentisani, on the growth of Candida albicans and Candida glabrata biofilms are unknown. OBJECTIVE: To determine the effect of S. dentisani on the different phases of C. albicans and C. glabrata biofilm development. METHODS: Growth quantification and ultrastructural analyses were performed on biofilms of C. albicans ATCC 90028, C. glabrata ATCC 2001, and clinical isolates of C. albicans from oral candidiasis (CA-C1), caries (CA-CR1), and periodontal pocket (CA-P1) treated with cell suspensions of S. dentisani CECT 7746. Cell viability was determined by quantifying colony-forming units (CFU/mL). The ultrastructural analyses were done with atomic force microscopy. RESULTS: S. dentisani induced a significant reduction (p < 0.05) of CFU/mL of immature and mature biofilm in all strains of C. albicans and C. glabrata. Microscopic analysis revealed that S. dentisani reduced C. albicans density in mixed biofilm. The fungus-bacteria interaction affected cell membrane integrity in yeast. CONCLUSION: For the first time, our data elucidate the antifungal effect of S. dentisani on the development of C. albicans and C. glabrata biofilms, supporting its usefulness as a niche-specific probiotic to prevent and treat oral dysbiosis.

Periodontal pathogen Aggregatibacter actinomycetemcomitans JP2 correlates with colonic leukocytes decrease and gut microbiome imbalance in mice.

AIM: Evidence suggests that translocation of oral pathogens through the oral-gut axis may induce intestinal dysbiosis. This study aimed to evaluate the impact of a highly leukotoxic Aggregatibacter actinomycetemcomitans (Aa) strain on the gut microbiota, intestinal mucosal integrity and immune system in healthy mice. METHODS: Eight-week-old male C57BL6 mice were divided into control (n = 16) and JP2 groups (n = 19), which received intragastric gavage with PBS and with a suspension of Aa JP2 (HK921), respectively, twice a week for 4 weeks. Colonic lamina propria, fecal material, serum, gingival tissues, and mandibles were obtained for analyses of leukocyte populations, inflammatory mediators, mucosal integrity, alveolar bone loss, and gut microbiota. Differences between groups for these parameters were examined by non-parametric tests. RESULTS: The gut microbial richness and the number of colonic macrophages, neutrophils, and monocytes were significantly lower in Aa JP2-infected mice than in controls (p < .05). In contrast, infected animals showed higher abundance of Clostridiaceae, Lactobacillus taiwanensis, Helicobacter rodentium, higher levels of IL-6 expression in colonic tissues, and higher splenic MPO activity than controls (p < .05). No differences in tight junction expression, serum endotoxin levels, and colonic inflammatory cytokines were observed between groups. Infected animals presented also slightly more alveolar bone loss and gingival IL-6 levels than controls (p < .05). CONCLUSION: Based on this model, intragastric administration of Aa JP2 is associated with changes in the gut ecosystem of healthy hosts, characterized by less live/recruited myeloid cells, enrichment of the gut microbiota with pathobionts and decrease in commensals. Negligible levels of colonic pro-inflammatory cytokines, and no signs of mucosal barrier disruption were related to these changes.

A Two-Faced Gut Microbiome: Butyrogenic and Proinflammatory Bacteria Predominate in the Intestinal Milieu of People Living with HIV from Western Mexico.

HIV infection results in marked alterations in the gut microbiota (GM), such as the loss of microbial diversity and different taxonomic and metabolic profiles. Despite antiretroviral therapy (ART) partially ablating gastrointestinal alterations, the taxonomic profile after successful new ART has shown wide variations. Our objective was to determine the GM composition and functions in people living with HIV (PLWHIV) under ART in comparison to seronegative controls (SC). Fecal samples from 21 subjects (treated with integrase strand-transfer inhibitors, INSTIs) and 18 SC were included. We employed 16S rRNA amplicon sequencing, coupled with PICRUSt2 and fecal short-chain fatty acid (SCFA) quantification by gas chromatography. The INSTI group showed a decreased α-diversity (p < 0.001) compared to the SC group, at the expense of increased amounts of Pseudomonadota (Proteobacteria), Segatella copri, Lactobacillus, and Gram-negative bacteria. Concurrently, we observed an enrichment in Megasphaera and Butyricicoccus, both SCFA-producing bacteria, and significant elevations in fecal butyrate in this group (p < 0.001). Interestingly, gut dysbiosis in PLWHIV was characterized by a proinflammatory environment orchestrated by Pseudomonadota and elevated levels of butyrate associated with bacterial metabolic pathways, as well as the evident presence of butyrogenic bacteria. The role of this unique GM in PLWHIV should be evaluated, as well as the use of butyrate-based supplements and ART regimens that contain succinate, such as tenofovir disoproxil succinate. This mixed profile is described for the first time in PLWHIV from Mexico.

Metagenome-assembled genomes (MAGs) suggest an acetate-driven protective role in gut microbiota disrupted by Clostridioides difficile.

Clostridioides difficile may have a negative impact on gut microbiota composition in terms of diversity and abundance, thereby triggering functional changes supported by the differential presence of genes involved in significant metabolic pathways, such as short-chain fatty acids (SCFA). This work has evaluated shotgun metagenomics data regarding 48 samples from four groups classified according to diarrhea acquisition site (community- and healthcare facility-onset) and positive or negative Clostridioides difficile infection (CDI) result. The metagenomic-assembled genomes (MAGs) obtained from each sample were taxonomically assigned for preliminary comparative analysis concerning differences in composition among groups. The predicted genes involved in metabolism, transport, and signaling remained constant in microbiota members; characteristic patterns were observed in MAGs and genes involved in SCFA butyrate and acetate metabolic pathways for each study group. A decrease in genera and species, as well as relative MAG abundance with the presence of the acetate metabolism-related gene, was evident in the HCFO/- group. Increased antibiotic resistance markers (ARM) were observed in MAGs along with the genes involved in acetate metabolism. The results highlight the need to explore the role of acetate in greater depth as a potential protector of the imbalances produced by CDI, as occurs in other inflammatory intestinal diseases.

Microbial Dynamics in Ophthalmic Health: Exploring the Interplay between Human Microbiota and Glaucoma Pathogenesis.

The human microbiome has a crucial role in the homeostasis and health of the host. These microorganisms along with their genes are involved in various processes, among these are neurological signaling, the maturation of the immune system, and the inhibition of opportunistic pathogens. In this sense, it has been shown that a healthy ocular microbiota acts as a barrier against the entry of pathogens, contributing to the prevention of infections. In recent years, a relationship has been suggested between microbiota dysbiosis and the development of neurodegenerative diseases. In patients with glaucoma, it has been observed that the microbiota of the ocular surface, intraocular cavity, oral cavity, stomach, and gut differ from those observed in healthy patients, which may suggest a role in pathology development, although the evidence remains limited. The mechanisms involved in the relationship of the human microbiome and this neurodegenerative disease remain largely unknown. For this reason, the present review aims to show a broad overview of the influence of the structure and composition of the human oral and gut microbiota and relate its dysbiosis to neurodegenerative diseases, especially glaucoma.

Intestinal microbiota diversity from broilers with runting and stunting syndrome performed by metagenomics.

Runting and stunting syndrome (RSS) is an enteric viral disease in commercial poultry that directly affects gut health; however, its influence on gut microbiota remains unknown. This study aimed to investigate the compositional changes in the bacterial community of the ileum of 7-day-old broiler chicks naturally affected or not affected by RSS, using next-generation sequencing (NGS) technology. Twenty-one samples were obtained from the ileal contents and mucosa of 11 chicks with RSS and 10 healthy chicks, raised in a dark house system located on a farm in the state of Minas Gerais, Brazil. The results revealed overall changes in the gut microbiota of the chicks with RSS, including a decrease in microbial richness and diversity. In particular, there was a decrease in Lactobacillus and an increase in Candidatus Arthromitus and Clostridium sensu stricto 1. These results indicate a relationship between viral infection and the gut microbial composition, which can cause gut dysbiosis and may influence inflammation in this organ.RESEARCH HIGHLIGHTS RSS causes dysbiosis of the gut microbiota of the ilea of chicks.A difference was found in gut microbiota between chicks with or without RSS.Candidatus Arthromitus was predominant in chicks with RSS.Clostridium sensu stricto 1 was strictly associated with chicks with RSS.

Polyphenolic Compounds: Orchestrating Intestinal Microbiota Harmony during Aging.

In the aging process, physiological decline occurs, posing a substantial threat to the physical and mental well-being of the elderly and contributing to the onset of age-related diseases. While traditional perspectives considered the maintenance of life as influenced by a myriad of factors, including environmental, genetic, epigenetic, and lifestyle elements such as exercise and diet, the pivotal role of symbiotic microorganisms had been understated. Presently, it is acknowledged that the intestinal microbiota plays a profound role in overall health by signaling to both the central and peripheral nervous systems, as well as other distant organs. Disruption in this bidirectional communication between bacteria and the host results in dysbiosis, fostering the development of various diseases, including neurological disorders, cardiovascular diseases, and cancer. This review aims to delve into the intricate biological mechanisms underpinning dysbiosis associated with aging and the clinical ramifications of such dysregulation. Furthermore, we aspire to explore bioactive compounds endowed with functional properties capable of modulating and restoring balance in this aging-related dysbiotic process through epigenetics alterations.

Human immunodeficiency virus and oral microbiota: mutual influence on the establishment of a viral gingival reservoir in individuals under antiretroviral therapy.

The role of the oral microbiota in the overall health and in systemic diseases has gained more importance in the recent years, mainly due to the systemic effects that are mediated by the chronic inflammation caused by oral diseases, such as periodontitis, through the microbial communities of the mouth. The chronic infection by the human immunodeficiency virus (HIV) interacts at the tissue level (e.g. gut, genital tract, brain) to create reservoirs; the modulation of the gut microbiota by HIV infection is a good example of these interactions. The purpose of the present review is to assess the state of knowledge on the oral microbiota (microbiome, mycobiome and virome) of HIV-infected patients in comparison to that of HIV-negative individuals and to discuss the reciprocal influence of HIV infection and oral microbiota in patients with periodontitis on the potential establishment of a viral gingival reservoir. The influence of different clinical and biological parameters are reviewed including age, immune and viral status, potent antiretroviral therapies, smoking, infection of the airway and viral coinfections, all factors that can modulate the oral microbiota during HIV infection. The analysis of the literature proposed in this review indicates that the comparisons of the available studies are difficult due to their great heterogeneity. However, some important findings emerge: (i) the oral microbiota is less influenced than that of the gut during HIV infection, although some recurrent changes in the microbiome are identified in many studies; (ii) severe immunosuppression is correlated with altered microbiota and potent antiretroviral therapies correct partially these modifications; (iii) periodontitis constitutes a major factor of dysbiosis, which is exacerbated in HIV-infected patients; its pathogenesis can be described as a reciprocal reinforcement of the two conditions, where the local dysbiosis present in the periodontal pocket leads to inflammation, bacterial translocation and destruction of the supporting tissues, which in turn enhances an inflammatory environment that perpetuates the periodontitis cycle. With the objective of curing viral reservoirs of HIV-infected patients in the future years, it appears important to develop further researches aimed at defining whether the inflamed gingiva can serve of viral reservoir in HIV-infected patients with periodontitis.

Vaginal Microbiota and HPV in Latin America: A Narrative Review.

With the expansion of human microbiome studies in the last 15 years, we have realized the immense implications of microbes in human health. The human holobiont is now accepted, given the commensal relationships with bacteria, fungi, parasites, viruses, and human cells. The cervicovaginal microbiota is a specific case within the human microbiome where diversity is lower to maintain a chemical barrier of protection against infections. This narrative review focuses on the vaginal microbiome. It summarizes key findings on how native bacteria protect women from disease or predispose them to damaging inflammatory processes with an emphasis on the role of HPV infections in Latin America, one of the world's regions with the highest cervical cancer prevalence.