RESUMO
BACKGROUND: In this study we shed light on ongoing trends in contraceptive use in Flanders (Belgium). Building on the fundamental cause theory and social diffusion of innovation theory, we examine socio-economic gradients in contraceptive use and the relationship to health behaviours. METHODS: Using the unique and recently collected (2020) ISALA data, we used multinomial logistic regression to model the uptake of contraceptives and its association to educational level and health behaviour (N:4316 women). RESULTS: Higher educated women, and women with a healthy lifestyle especially, tend to use non-hormonal contraceptives or perceived lower-dosage hormonal contraceptives that are still trustworthy from a medical point of view. Moreover, we identified a potentially vulnerable group in terms of health as our results indicate that women who do not engage in preventive health behaviours are more likely to use no, or no modern, contraceptive method. DISCUSSION: The fact that higher educated women and women with a healthy lifestyle are less likely to use hormonal contraceptive methods is in line with patient empowerment, as women no longer necessarily follow recommendations by healthcare professionals, and there is a growing demand for naturalness in Western societies. CONCLUSION: The results of this study can therefore be used to inform policy makers and reproductive healthcare professionals, since up-to-date understanding of women's contraceptive choices is clearly needed in order to develop effective strategies to prevent sexually transmitted infections and unplanned pregnancies, and in which women can take control over their sexuality and fertility in a comfortable and pleasurable way.
Assuntos
Comportamento Contraceptivo , Comportamentos Relacionados com a Saúde , Humanos , Feminino , Adulto , Bélgica , Comportamento Contraceptivo/estatística & dados numéricos , Comportamento Contraceptivo/psicologia , Adulto Jovem , Escolaridade , Pessoa de Meia-Idade , Adolescente , Anticoncepção/estatística & dados numéricos , Anticoncepção/métodos , Comportamento de Escolha , Conhecimentos, Atitudes e Prática em SaúdeRESUMO
Strategies against the opportunistic fungal pathogen Candida albicans based on probiotic microorganisms represent a promising alternative to traditional antifungals. Here, we investigated the effects of Lactobacillaceae isolates from fermented foods or the human vagina, alone or in combination with the probiotic yeast Saccharomyces cerevisiae CNCM I-3856, against C. albicans in vitro. Nine out of nineteen tested strains of Lactobacillaceae inhibited growth of C. albicans with inhibition zones of 1-3 mm in spot assays. Five out of nineteen lactobacilli tested as such or in combination with S. cerevisiae CNCM I-3856 also significantly inhibited C. albicans hyphae formation, including Limosilactobacillus fermentum LS4 and L. fermentum LS5 resulting in respectively 62% and 78% hyphae inhibition compared to the control. Thirteen of the tested nineteen lactobacilli aggregated with the yeast form of C. albicans, with Lactiplantibacillus carotarum AMBF275 showing the strongest aggregation. The aggregation was enhanced when lactobacilli were combined with S. cerevisiae CNCM I-3856. No significant antagonistic effects were observed between the tested lactobacilli and S. cerevisiae CNCM I-3856. The multifactorial activity of Lactobacillaceae strains alone or combined with the probiotic S. cerevisiae CNCM I-3856 against C. albicans without antagonistic effects between the beneficial strains, paves the way for developing consortium probiotics for in vivo applications.
Assuntos
Candida albicans , Lactobacillus , Probióticos , Saccharomyces cerevisiae , Candida albicans/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/efeitos dos fármacos , Probióticos/farmacologia , Lactobacillus/fisiologia , Humanos , Hifas/efeitos dos fármacos , Hifas/crescimento & desenvolvimento , Antibiose , Feminino , Vagina/microbiologiaRESUMO
Frequent exposure to sea spray aerosols (SSA) containing marine microorganisms and bioactive compounds may influence human health. However, little is known about potential immunostimulation by SSA exposure. This study focuses on the effects of marine bacteria and endotoxins in SSA on several receptors and transcription factors known to play a key role in the human innate immune system. SSA samples were collected in the field (Ostend, Belgium) or generated in the lab using a marine aerosol reference tank (MART). Samples were characterized by their sodium contents, total bacterial counts, and endotoxin concentrations. Human reporter cells were exposed to SSA to investigate the activation of toll-like receptor 4 (TLR4) in HEK-Blue hTLR4 cells and TLR2/6 in HEK-Blue hTLR2/6 cells, as well as the activation of nuclear factor kappa B (NF-κB) and interferon regulatory factors (IRF) in THP1-Dual monocytes. These responses were then correlated to the total bacterial counts and endotoxin concentrations to explore dose-effect relationships. Field SSA contained from 3.0 × 103 to 6.0 × 105 bacteria/m3 air (averaging 2.0 ± 1.9 × 105 bacteria/m3 air) and an endotoxin concentration ranging from 7 to 1217 EU/m3 air (averaging 389 ± 434 EU/m3 air). In contrast, MART SSA exhibited elevated levels of total bacterial count (from 2.0 × 105 to 2.4 × 106, averaging 7.3 ± 5.5 × 105 cells/m3 air) and endotoxin concentration from 536 to 2191 (averaging 1310 ± 513 EU/m3 air). SSA samples differentially activated TLR4, TLR2/6, NF-κB and IRF. These immune responses correlated dose-dependently with the total bacterial counts, endotoxin levels, or both. This study sheds light on the immunostimulatory potential of SSA and its underlying mechanisms, highlighting the need for further research to deepen our understanding of the health implications of SSA exposure.
Assuntos
Aerossóis , Endotoxinas , NF-kappa B , Humanos , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo , Fatores Reguladores de Interferon/metabolismo , Receptor 2 Toll-Like/metabolismo , Bactérias , Poluentes Atmosféricos , Bélgica , Imunidade InataRESUMO
In patients with presumptive tuberculosis (TB) in whom the diagnosis of TB was excluded, understanding the bacterial etiology of lower respiratory tract infections (LRTIs) is important for optimal patient management. A secondary analysis was performed on a cohort of 250 hospitalized patients with symptoms of TB. Bacterial DNA was extracted from sputum samples for Illumina 16S rRNA sequencing to identify bacterial species based on amplicon sequence variant level. The bacterial pathogen most likely to be responsible for the patients' LRTI could only be identified in a minority (6.0%, 13/215) of cases based on 16S rRNA amplicon sequencing: Mycoplasma pneumoniae (n = 7), Bordetella pertussis (n = 2), Acinetobacter baumanii (n = 2), and Pseudomonas aeruginosa (n = 2). Other putative pathogens were present in similar proportions of Xpert Ultra-positive and Xpert Ultra-negative sputum samples. The presence of Streptococcus (pseudo)pneumoniae appeared to increase the odds of radiological abnormalities (aOR 2.5, 95% CI 1.12-6.16) and the presence of S. (pseudo)pneumoniae (aOR 5.31, 95% CI 1.29-26.6) and Moraxella catarrhalis/nonliquefaciens (aOR 12.1, 95% CI 2.67-72.8) increased the odds of 6-month mortality, suggesting that these pathogens might have clinical relevance. M. pneumoniae, B. pertussis, and A. baumanii appeared to be the possible causes of TB-like symptoms. S. (pseudo)pneumoniae and M. catarrhalis/nonliquefaciens also appeared of clinical relevance based on 16S rRNA amplicon sequencing. Further research using tools with higher discriminatory power than 16S rRNA sequencing is required to develop optimal diagnostic and treatment strategies for this population.IMPORTANCEThe objective of this study was to identify possible bacterial lower respiratory tract infection (LRTI) pathogens in hospitalized patients who were initially suspected to have TB but later tested negative using the Xpert Ultra test. Although 16S rRNA was able to identify some less common or difficult-to-culture pathogens such as Mycoplasma pneumoniae and Bordetella pertussis, one of the main findings of the study is that, in contrast to what we had hypothesized, 16S rRNA is not a method that can be used to assist in the management of patients with presumptive TB having a negative Xpert Ultra test. Even though this could be considered a negative finding, we believe it is an important finding to report as it highlights the need for further research using different approaches.
Assuntos
Mycobacterium tuberculosis , Infecções Respiratórias , Tuberculose Pulmonar , Tuberculose , Humanos , RNA Ribossômico 16S , Tuberculose Pulmonar/microbiologia , Mycobacterium tuberculosis/genética , Rifampina/uso terapêutico , Escarro/microbiologia , Sensibilidade e Especificidade , Tuberculose/tratamento farmacológico , Infecções Respiratórias/tratamento farmacológicoRESUMO
Antibiotics and cystic fibrosis transmembrane conductance regulator (CFTR) modulators play a pivotal role in cystic fibrosis (CF) treatment, but both have limitations. Antibiotics are linked to antibiotic resistance and disruption of the airway microbiome, while CFTR modulators are not widely accessible, and structural lung damage and pathogen overgrowth still occur. Complementary strategies that can beneficially modulate the airway microbiome in a preventive way are highly needed. This could be mediated via oral probiotics, which have shown some improvement of lung function and reduction of airway infections and exacerbations, as a cost-effective approach. However, recent data suggest that specific and locally administered probiotics in the respiratory tract might be a more targeted approach to prevent pathogen outgrowth in the lower airways. This review aims to summarize the current knowledge on the CF airway microbiome and possibilities of microbiome treatments to prevent bacterial and/or viral infections and position them in the context of current CF therapies.
Assuntos
Fibrose Cística , Microbiota , Humanos , Fibrose Cística/terapia , Fibrose Cística/microbiologia , Regulador de Condutância Transmembrana em Fibrose Cística , Pulmão , Antibacterianos/uso terapêuticoRESUMO
Radiotherapy is a commonly employed treatment for colorectal cancer, yet its radiotoxicity-related impact on healthy tissues raises significant health concerns. This highlights the need to use radioprotective agents to mitigate these side effects. This review presents the current landscape of human translational radiobiology, outlining the limitations of existing models and proposing engineering solutions. We delve into radiotherapy principles, encompassing mechanisms of radiation-induced cell death and its influence on normal and cancerous colorectal cells. Furthermore, we explore the engineering aspects of microphysiological systems to represent radiotherapy-induced gastrointestinal toxicity and how to include the gut microbiota to study its role in treatment failure and success. This review ultimately highlights the main challenges and future pathways in translational research for pelvic radiotherapy-induced toxicity. This is achieved by developing a humanized in vitro model that mimics radiotherapy treatment conditions. An in vitro model should provide in-depth analyses of host-gut microbiota interactions and a deeper understanding of the underlying biological mechanisms of radioprotective food supplements. Additionally, it would be of great value if these models could produce high-throughput data using patient-derived samples to address the lack of human representability to complete clinical trials and improve patients' quality of life.
RESUMO
AIMS: To test the in vitro probiotic potential and starter culture capacity of lactic acid bacteria (LAB) isolated from Naaqe and Cheka, cereal-based Ethiopian traditional fermented beverages. METHODS AND RESULTS: A total of 44 strains were isolated from spontaneously fermented Ethiopian cereal-based beverages, Naaqe and Cheka with 24 putatively identified as LAB and 14 identified up to the species level. The species Limosilactobacillus fermentum (6/12; 50%) and Weissella confusa (5/12, 41.67%) were the predominant species identified from Naaqe, while the two Cheka isolates were L. fermentum and Pediococcus pentosaceus. Six LAB strains inhibited eight of the nine gastrointestinal indicator key pathogens in Ethiopia, including Escherichia coli, Salmonella enterica subsp. enterica var. Typhimurium, Staphylococcus aureus, Shigella flexneri, and Listeria monocytogenes. Three of the LAB isolates exhibited strain-specific immunostimulation in human monocytes. Based on these probiotic properties and growth, six strains were selected for in situ evaluation in a mock fermentation of Naaqe and Cheka. During primary fermentations, L. fermentum 73B, P. pentosaceus 74D, L. fermentum 44B, W. confusa 44D, L. fermentum 82C, and Weissella cibaria 83E and their combinations demonstrated higher pH-lowering properties and colony-forming unit counts compared to the control spontaneous fermentation. The same pattern was also observed in the secondary mock fermentation by the Naaqe LAB isolates. CONCLUSIONS: In this study, we selected six LAB strains with antipathogenic, immunostimulatory, and starter culture potentials that can be used as autochthonous probiotic starters for Naaqe and Cheka fermentations once their health benefit is ascertained in a clinical trial as a next step.
Assuntos
Lactobacillales , Limosilactobacillus fermentum , Probióticos , Humanos , Grão Comestível/microbiologia , Bebidas/microbiologia , FermentaçãoRESUMO
IMPORTANCE: Plant protection products are essential for ensuring food production, but their use poses a threat to human and environmental health, and their efficacy is decreasing due to the acquisition of resistance by pathogens. Stricter regulations and consumer demand for cleaner produce are driving the search for safer and more sustainable alternatives. Microbial biocontrol agents, such as microorganisms with antifungal activity, have emerged as a promising alternative management strategy, but their commercial use has been limited by poor establishment and spread on crops. This study presents a novel system to overcome these challenges. The biocontrol agent Lactiplantibacillus plantarum AMBP214 was spray-dried and successfully dispersed to strawberry flowers via bumblebees. This is the first report of combining spray-dried, non-spore-forming bacteria with pollinator-dispersal, which scored better than the state-of-the-art in terms of dispersal to the plant (CFU/flower), and resuscitation of the biocontrol agent. Therefore, this new entomovectoring system holds great promise for the use of biocontrol agents for disease management in agriculture.
Assuntos
Fragaria , Controle Biológico de Vetores , Animais , Abelhas , Humanos , Produtos Agrícolas , Fragaria/microbiologiaRESUMO
Understanding the composition and function of the vaginal microbiome is crucial for reproductive and overall health. Here we established the Isala citizen-science project to analyse the vaginal microbiomes of 3,345 women in Belgium (18-98 years) through self-sampling, 16S amplicon sequencing and extensive questionnaires. The overall vaginal microbiome composition was strongly tied to age, childbirth and menstrual cycle phase. Lactobacillus species dominated 78% of the vaginal samples. Specific bacterial taxa also showed to co-occur in modules based on network correlation analysis. Notably, the module containing Lactobacillus crispatus, Lactobacillus jensenii and Limosilactobacillus taxa was positively linked to oestrogen levels and contraceptive use and negatively linked to childbirth and breastfeeding. Other modules, named after abundant taxa (Gardnerella, Prevotella and Bacteroides), correlated with multiple partners, menopause, menstrual hygiene and contraceptive use. With this resource-rich vaginal microbiome map and associated health, life-course, lifestyle and dietary factors, we provide unique data and insights for follow-up clinical and mechanistic research.
Assuntos
Higiene , Microbiota , Feminino , Humanos , Menstruação , Vagina/microbiologia , AnticoncepcionaisRESUMO
A novel strain of the genus Lactobacillus, named AMBV1719T, was isolated from the vagina of a healthy participant in our large-scale citizen science project on the female microbiome, named Isala. Phylogenetic analysis showed that the 16S rRNA gene of AMBV1719T is most similar to that of Lactobacillus taiwanensis with a sequence similarity of 99.873â%. However, a genome-wide comparison using average nucleotide identity (ANI) revealed that isolate AMBV1719T showed the highest ANI with Lactobacillus paragasseri JCM 5343T, with a value of only 88.17â%. This low ANI value with the most closely related strains known to date indicated that AMBV1719T represents a distinct species. This strain has a limited ability to degrade carbon sources compared to Lactobacillus gasseri, indicating its adaptation to the host. Its genome has a length of 2.12 Mb with a G+C content of 34.8 mol%. We thus propose the name Lactobacillus isalae sp. nov. for this novel species, with AMBV1719T (=LMG 32886T=CECT 30756T) as the type strain.
Assuntos
Ácidos Graxos , Genes Bacterianos , Humanos , Feminino , Filogenia , RNA Ribossômico 16S/genética , Composição de Bases , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Hibridização de Ácido Nucleico , Análise de Sequência de DNA , Ácidos Graxos/química , LactobacillusRESUMO
Diverse terms have been used in the literature to refer to the health benefits obtained from the administration of non-viable microorganisms or their cell fragments and metabolites. In an effort to provide continuity to this emerging field, the International Scientific Association of Probiotics and Prebiotics (ISAPP) convened a panel of experts to consider this category of substances and adopted the term postbiotic, which they defined as a "preparation of inanimate microorganisms and/or their components that confers a health benefit on the host." This definition does not stipulate any specific health benefit, finished product, target population or regulatory status. In this perspective article, we focused on postbiotics developed for pharmaceutical uses, including medicinal products and medical devices. We address how this field is regulated for products based on inanimate microorganisms, marketing considerations and existing examples of postbiotics products developed as cosmetics for the skin, for vaginal health, and as orally consumed products. We focus on the European Union for regulatory aspects, but also give examples from other geographical areas.
RESUMO
IMPORTANCE: The salivary microbiome has been proven to play a crucial role in local and systemic diseases. Moreover, the effects of biological and lifestyle factors such as oral hygiene and smoking on this microbial community have already been explored. However, what was not yet well understood was the natural variation of the saliva microbiome in healthy women and how this is associated with specific use of hormonal contraception and with the number of different sexual partners with whom microbiome exchange is expected regularly. In this paper, we characterized the salivary microbiome of 255 healthy women of reproductive age using an in-depth questionnaire and self-sampling kits. Using the large metadata set, we were able to investigate the associations of several host-related and lifestyle variables with the salivary microbiome profiles. Our study shows a high preservation between individuals.
Assuntos
Microbiota , Reprodução , Humanos , Feminino , Saliva , Parceiros Sexuais , Nível de Saúde , RNA Ribossômico 16SRESUMO
A novel strain of the genus Lactiplantibacillus, named AMBF275T, was isolated from fermented carrot juice, a salted fermented beverage dominated by lactic acid bacteria. The results of phylogenetic analysis indicated that the 16S rRNA gene of AMBF275T is most similar to the 16S rRNA gene of Lactiplantibacillus garii FI11369T with a sequence similarity of 99.4â%. However, a genome-wide comparison using average nucleotide identity (ANI) revealed that AMBF275T and L. garii FI11369T have an ANI of only 82.35â%. ANI values between AMBF275T and other representative strains of species of the genus Lactiplantibacillus from the Genome Taxonomy Database (GTDB) were even lower than this 82.35â%, indicating that AMBF275T represents a distinct species. We thus propose the name Lactiplantibacillus carotarum sp. nov. for this novel species, with AMBF275T (=LMG 32885T, =CECT 30757T) as the type strain.
Assuntos
Daucus carota , Análise de Sequência de DNA , Filogenia , RNA Ribossômico 16S/genética , Fermentação , Genes Bacterianos , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Hibridização de Ácido Nucleico , Ácidos Graxos/química , Microbiologia de AlimentosRESUMO
BACKGROUND AND AIMS: We aimed to identify mucin-microbiome signatures shaping the tumor microenvironment in gastric adenocarcinomas and clinical outcomes. METHODS: We performed high-throughput profiling of the mucin phenotypes present in 108 gastric adenocarcinomas and 20 functional dyspepsia cases using validated mucin-based RT-qPCRs with subsequent immunohistochemistry validation and correlated the data with clinical outcome parameters. The gastric microbiota was assessed by 16S rRNA gene sequencing, taxonomy, and community composition determined, microbial networks analyzed, and the metagenome inferred in association with mucin phenotypes and expression. RESULTS: Gastric adenocarcinomas with an intestinal mucin environment or high-level MUC13 expression are associated with poor survival. On the contrary, gastric MUC5AC or MUC6 abundance was associated with a more favorable outcome. The oral taxa Neisseria, Prevotella, and Veillonella had centralities in tumors with intestinal and mixed phenotypes and were associated with MUC13 overexpression, highlighting their role as potential drivers in MUC13 signaling in GC. Furthermore, dense bacterial networks were observed in intestinal and mixed mucin phenotype tumors whereas the lowest community complexity was shown in null mucin phenotype tumors due to higher Helicobacter abundance resulting in a more decreased diversity. Enrichment of oral or intestinal microbes was mucin phenotype dependent. More specifically, intestinal mucin phenotype tumors favored the establishment of pro-inflammatory oral taxa forming strong co-occurrence networks. CONCLUSIONS: Our results emphasize key roles for mucins in gastric cancer prognosis and shaping microbial networks in the tumor microenvironment. Specifically, the enriched oral taxa associated with aberrant MUC13 expression can be potential biomarkers in predicting disease outcomes. Video Abstract.
Assuntos
Adenocarcinoma , Microbiota , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Mucina-2/genética , Microambiente Tumoral , RNA Ribossômico 16S/genética , Mucina-6/genética , FenótipoRESUMO
Pelvic irradiation-induced mucositis secondarily leads to dysbiosis, which seriously affects patients' quality of life after treatment. No safe and effective radioprotector or mitigator has yet been approved for clinical therapy. Here, we investigated the potential protective effects of fresh biomass of Limnospira indica PCC 8005 against ionizing irradiation-induced mucositis and dysbiosis in respect to benchmark probiotic Lacticaseibacillus rhamnosus GG ATCC 53103. For this, mice were supplemented daily before and after 12 Gy X-irradiation of the pelvis. Upon sacrifice, food supplements' efficacy was assessed for intestinal barrier protection, immunomodulation and changes in the microbiota composition. While both could not confer barrier protection or significant immunomodulatory effects, 16S microbial profiling revealed that L. indica PCC 8005 and L. rhamnosus GG could prevent pelvic irradiation-induced dysbiosis. Altogether, our data show that-besides benchmarked L. rhamnosus GG-L. indica PCC 8005 is an interesting candidate to further explore as a radiomitigator counteracting pelvic irradiation-induced dysbiosis in the presented in vivo irradiation-gut-microbiota platform.
RESUMO
This study investigates an evolutionary hypothesis of gossip postulating that in humans it serves a similar function as social grooming in other primates. It examines whether gossip decreases physiological markers of stress and increases markers of positive emotionality and sociability. Dyads of friends (N = 66) recruited at the university, participated in an experiment where they experienced a stressor followed by social interaction (gossip or control task). Individual levels of salivary cortisol and [Formula: see text]-endorphins were assessed at before and after social interactions. Sympathetic activity and parasympathetic activity were monitored throughout the experiment. Individual differences in Tendency and Attitude towards Gossip were investigated as potential covariates. Gossip condition was characterized with increased sympathetic and parasympathetic activity, but did not differ in cortisol or [Formula: see text]-endorphins levels. However, high Tendency to Gossip was associated with decreases in cortisol. Gossip was shown to be more emotionally salient than non-social talk, but the evidence with regard to lowering stress was not sufficient to support an analogy to social grooming.
Assuntos
Comunicação , Hidrocortisona , Humanos , Psicofisiologia , Amigos , Interação SocialRESUMO
Vaccination is the most effective way to confer potent and long-term protection from infectious diseases. However, poorer responses to immunization are common in young adults with sub-optimal immune health and the elderly because of immunosenescence and increased comorbidities. Recent mechanistic studies have highlighted that the microbiota and its compounds modulate many molecular pathways that can influence the host immune system. Consequently, altering the microbiota composition or activity with immunonutrition, specifically with biotic interventions (probiotics, prebiotics, synbiotics, or postbiotics), may enhance the immune response and vaccine efficacy. This review aims to examine the available data for these biotic strategies to provide clinicians, researchers, and vaccine developers with a mechanistically driven synthesis of how biotic interventions could modulate the immune responses to vaccination. The article describes some postulated mechanistic pathways involved in immunological responses to vaccines and immunomodulation with biotic interventions. Randomized clinical trials were also reviewed to evaluate the impact of specific biotic interventions on vaccination outcomes in different age groups. Few strains and formulations significantly increased antigen-specific antibody titers in individual of all ages. However, studies have also pointed to a substantial heterogeneity that can be attributed to the difference in biotic intervention, strain, dose, viability, type of vaccine antigen, study location, as well as duration, and timing of administration. Future investigations should focus on establishing optimal strains, doses, and timing of administration with respect to vaccination, especially in the elderly and children, where vaccine effectiveness and duration of immunization matter.
Assuntos
Probióticos , Simbióticos , Vacinas , Criança , Adulto Jovem , Humanos , Idoso , Prebióticos , ImunidadeRESUMO
Whether the human fetus and the prenatal intrauterine environment (amniotic fluid and placenta) are stably colonized by microbial communities in a healthy pregnancy remains a subject of debate. Here we evaluate recent studies that characterized microbial populations in human fetuses from the perspectives of reproductive biology, microbial ecology, bioinformatics, immunology, clinical microbiology and gnotobiology, and assess possible mechanisms by which the fetus might interact with microorganisms. Our analysis indicates that the detected microbial signals are likely the result of contamination during the clinical procedures to obtain fetal samples or during DNA extraction and DNA sequencing. Furthermore, the existence of live and replicating microbial populations in healthy fetal tissues is not compatible with fundamental concepts of immunology, clinical microbiology and the derivation of germ-free mammals. These conclusions are important to our understanding of human immune development and illustrate common pitfalls in the microbial analyses of many other low-biomass environments. The pursuit of a fetal microbiome serves as a cautionary example of the challenges of sequence-based microbiome studies when biomass is low or absent, and emphasizes the need for a trans-disciplinary approach that goes beyond contamination controls by also incorporating biological, ecological and mechanistic concepts.
Assuntos
Biomassa , Contaminação por DNA , Feto , Microbiota , Animais , Feminino , Humanos , Gravidez , Líquido Amniótico/imunologia , Líquido Amniótico/microbiologia , Mamíferos , Microbiota/genética , Placenta/imunologia , Placenta/microbiologia , Feto/imunologia , Feto/microbiologia , Reprodutibilidade dos TestesRESUMO
Several oral diseases are characterized by a shift within the oral microbiome towards a pathogenic, dysbiotic composition. Broad-spectrum antimicrobials are often part of patient care. However, because of the rising antibiotic resistance, alternatives are increasingly desirable. Alternatively, supplying beneficial species through probiotics is increasingly showing favorable results. Unfortunately, these probiotics are rarely evaluated comparatively. In this study, the in vitro effects of three known and three novel Lactobacillus strains, together with four novel Streptococcus salivarius strains were comparatively evaluated for antagonistic effects on proximal agar growth, antimicrobial properties of probiotic supernatant and the probiotic's effects on in vitro periodontal biofilms. Strain-specific effects were observed as differences in efficacy between genera and differences within genera. While some of the Lactobacillus candidates were able to reduce the periodontal pathobiont A. actinomycetemcomitans, the S. salivarius strains were not. However, the S. salivarius strains were more effective against periodontal pathobionts P. intermedia, P. gingivalis, and F. nucleatum. Vexingly, most of the Lactobacillus strains also negatively affected the prevalence of commensal species within the biofilms, while this was lower for S. salivarius strains. Both within lactobacilli and streptococci, some strains showed significantly more inhibition of the pathobionts, indicating the importance of proper strain selection. Additionally, some species showed reductions in non-target species, which can result in unexpected and unexplored effects on the whole microbiome.