Human Microbiome Journal最新文献

Coronavirus disease 2019 (COVID-19) is a rapidly emerging disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease begins as an infection of lungs, which is self-limiting in the majority of infections; however, some develop severe respiratory distress and organ failures. Lung microbiome, though neglected previously have received interest recently because of its association with several respiratory diseases and immunity. Lung microbiome can modify the risk and consequences of COVID-19 disease by activating an innate and adaptive immune response. In this review, we examine the current evidence on COVID-19 disease and lung microbiome, and how lung microbiome can affect SARS-CoV-2 infection and the outcomes of this disease. To date there is no direct evidence from human or animal studies on the role of lung microbiome in modifying COVID-19 disease; however, related studies support that microbiome can play an essential role in developing immunity against viral infections. Future studies need to be undertaken to find the relationship between lung microbiome and COVID-19 disease.

Enterococci are members of human gut microbiota which their colonization has been demonstrated even before birth. This indicates their importance in infant health. As this population is dynamic and varies with age, this study was designed to assess and compare the antibacterial effects of enterococci from breast-fed infants and those from adults. Fecal isolates of enterococci were isolated from infants and healthy adults and were identified to the species level by phenotypic and genotypic methods. Further, they were evaluated for their potential to exert antibacterial effect against ten standard bacterial strains using bilayer spot test. Of a total of eighty-nine recovered enterococcal isolates, Enterococcus faecium and E. faecalis were the most common species (98%) and showed inhibitory effects at least against one indicator strain. Comparison between isolates from two studied groups showed that isolates from neonates introduced significantly higher growth inhibitory effects against six indicator strains (P < 0.05) and these effects were frequently attributable to E. faecium isolates. In addition, the highest growth inhibitory effect was observed against Listeria monocytogenes. Antimicrobial effects of enterococci in human microbiota change during time. The beneficial role of these organisms within the neonatal period suggests the potential of enterococci from breast-fed infants for probiotic application.

Background

Diarrhea as the consequence of gastroenteritis is one of the most significant causes of infant’s deaths across the world. Over 700 000 child loses occur each year as a result of gastroenteritis infection. This study aimed at elucidating potential bacterial aetiological agents of diarrhoea within the selected rural settlements of Amathole District Municipality, Eastern Cape, South Africa. Standard culture-based methods and Polymerase chain reaction techniques were employed for the detection, isolation and validation of diarrheagenic E. coli (DEC) pathotypes and Salmonella species from diarrheal stool samples.

Results

A total of 208 (64%) isolates were positively affirmed by conventional Polymerase Chain Reaction as Diarrheagenic E. coli (DEC) and were further delineated into 4 DEC pathotypes and an additional 116 (36%) isolates were confirmed as Non-diarrheagenic E. coli. Among the confirmed DEC pathotypes, Enterotoxigenic E. coli (ETEC) (51%) was the most prevalent followed by Diffusely adherent E. coli DAEC (18%), Enteroaggregative E. coli (EAEC) (16%) and Enteropathogenic E. coli (EPEC) (15%). Subsequently; 62 (23%) of 263 Salmonella phenotypic isolates were also confirmed by conventional Polymerase Chain Reaction (PCR) using genus specific primer sets. Though sought; no presumptive isolates of Campylobacter species were detected from the diarrheal stool samples obtained in the study region.

Conclusion

The findings of this study elucidated bacterial pathogens co-infection of DEC and Salmonella species among diarrheal stool specimens, accentuating a significant public health concern.

Faecal microbiota transplantation (FMT) represents a unique procedure targeted to restoring the natural diversity of the gastrointestinal microbiome and prevent recurrence of a key nosocomial disease, namely, Clostridioides difficile infection (CDI). The aim of the present study was assessing the success rate and clinical efficacy of FMT at a clinic that introduced this procedure in Czechia in 2010 and still leads in the number of transplantations performed to date. Patients enrolled in the study received primary targeted antibiotic therapy, and after the CDI episode treatment, FMT administered as a secondary prophylaxis. After the procedure, patients were followed up. The treatment was defined as successful if colitis did not recur within 8 weeks. Logistic regression analysis was used for determining the odds ratios for the individual factor variants (patient age and sex, number of previous recurrences, severity of the treated CDI episodes, presence of chronic comorbidities, performance status, initial antibiotic treatment, mode of faecal-transplant application and use of fresh or frozen stool). In the 4-year interval involved (2015–2018), 172 patients were treated using faecal microbiota transplantation. The overall success rate was 76%. Subgroup analysis identified higher age, higher Charlson Comorbidity Index reflecting the presence and severity of long-term comorbidities and higher Eastern Cooperative Oncology Group (ECOG) performance scores as risk factors for treatment failure. In the period monitored, two serious adverse events were observed: Both were rectal-wall perforations occurring during the application of enemas of stool suspension. There was no lethality.

Patients colonized with antibiotic resistant bacteria are at risk of infections and spontaneous decolonization delays are highly variable between patients. The management of these patients is therefore time-consuming; requires patient isolation, and cohort policies. Fecal microbiota transplantation (FMT) has been used with the aim of shortening this gut colonization. Here, we proposed a comprehensive literature review on FMT utilization for gut antibiotics resistant bacteria decolonization. After literature research through Pubmed indexed for MEDLINE, we analyzed 23 studies with description of FMT utilization and analyze of gut decolonization. In total, the data involved 197 patients, 153 of whom underwent FMT. Overall, 66.7% (102/153) of the patients were decolonized after FMT. However, we noticed a lot of interpretation bias, such as variation in colonization definition and high disparities in FMT administration modalities. Two disparities were of special interest: repeated FMT seems to increase the effectiveness of decolonization, and gut decolonization with antibiotics before FMT was proposed by some authors, but with too few studies to draw a conclusion. Overall, the use of FMT is a promising perspective for intestinal decolonization, but it requires greater standardization.

The gut microbiome has a measurable impact on the brain, influencing stress, anxiety, depressive symptoms and social behaviour. This microbiome–gut–brain axis may be mediated by various mechanisms including neural, immune and endocrine signalling. To date, the majority of research has been conducted in animal models, while the limited number of human studies has focused on psychiatric conditions. Here the composition and diversity of the gut microbiome is investigated with respect to human personality. Using regression models to control for possible confounding factors, the abundances of specific bacterial genera are shown to be significantly predicted by personality traits. Diversity analyses of the gut microbiome reveal that people with larger social networks tend to have a more diverse microbiome, suggesting that social interactions may shape the microbial community of the human gut. In contrast, anxiety and stress are linked to reduced diversity and an altered microbiome composition. Together, these results add a new dimension to our understanding of personality and reveal that the microbiome–gut–brain axis may also be relevant to behavioural variation in the general population as well as to cases of psychiatric disorders.

Introduction

Autism Spectrum Disorder (ASD) is a collection of neurodevelopmental disorders defined by core deficits, including impaired communication, reciprocal social interaction, and stereotyped and repetitive patterns of behaviors. The salivary microbiota may serve as important indicators of oral and systemic health. In this pilot study, we identify components of the salivary microbiome in children with ASD.

Methods

Saliva specimens were collected from 11 children with ASD (mean age: 10.68 years) and from 10 typically-developing individuals. Microbial DNA was extracted and utilized as templates for PCR amplification with V3-V4 16S rDNA-specific primers and high-throughput MiSeq sequencing. Taxonomic operational unit analyses and salivary microbiota profiles were conducted by LC Sciences (Houston TX); individual microbial species were further compared between children with ASD and typically-developing individuals.

Results

Rothia species were found to be statistically more prevalent in children with ASD in comparison to typically-developing children (12.2-fold change; FDR p-value = 0.031). Alternately, Megasphaera, Moraxella, Neisseria, and Gemella species were all found at significantly higher levels in typically-developing children than children with ASD, displaying 39.2-, 31.9-, 18.8- and 14.0-fold differences, respectively (all with FDR p-values < 0.011). In boys with ASD, Moraxella and Neisseria species were found at significantly-higher levels compared to typically-developing counterparts, exhibiting 42.36- and 28.62-fold differences, respectively (FDR p-values of 0.011 and 0.0004).

Conclusion

Understanding the salivary microbiome in children with autism can lead to improved management of oral health and precision treatment planning. In addition, practitioners may be able to modify the oral microbiome as therapeutic regimens for ASD and other oral diseases.