Fernanda Valdez-Palomares

Irritable Bowel Syndrome (IBS) is a functional gastrointestinal disorder characterized by abdominal pain and altered bowel habit. IBS patients report that FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) diet induce or exacerbate their symptoms. It has been reported that low-FODMAP diet (LFD) improves the symptoms in 50%-80% of IBS patients. We aimed to identify IBS responders and non-responders' patients to LFD by determining baseline fecal microbial composition, sequencing the 16S rRNA gene V3-V4 region. Thirty-two participants with IBS were included, 29 women (90.62%) and three men (9.37%), and instructed to follow a four-week LFD, Visual Analogue Scale for IBS was used to assess intervention response. Twenty-two participants were responders (68.75%), and ten were non-responders (31.25%). Differential abundance analysis of Amplicon Sequence Variant (ASVs), before LFD, identified Prevotella 9 and Veillonella genus in responder group, and Barnesiella, Paraprevotella, Bifidobacterium and Ruminococcus 1 genus in non-responder group. After LFD, differentially abundant ASVs were only identified in R, belonging to Veilonella, Butyrivibrio, and 5 ASVs belonging to Ruminiclostridium 6 genus. Linear Discriminant Analysis (LDA), was used to classify patients by responsiveness, considering baseline abundance of 5 bacterial genera, LDA accuracy model was 96.87%, correctly classifying 95.45% of in responder group and 100% and non-responder group. In conclusion, bacterial biomarkers are useful to classify IBS individuals by responsiveness to LFD.

Mycobacterium tuberculosis infection has three discernible outcomes: active tuberculosis, latent tuberculosis, or clearance of the bacterium. The outcome of the infection depends on the interaction of the bacterium, the immune system, and the microbiome of the host. The current study uses 16S rRNA sequencing to determine the diversity and composition of the respiratory microbiome of drug-resistant and drug-sensitive tuberculosis patients as well as healthy volunteers. Tuberculosis patients exhibited increased microbial diversity and differentially abundant bacteria than healthy volunteers. Compositional differences were also observed when comparing drug-sensitive or -resistant tuberculosis patients. Finally, we defined and assessed the differences in the core sputum microbiota between tuberculosis patients and healthy volunteers. Our observations collectively suggest that in sputum, Mycobacterium tuberculosis infection is related to altered bacterial diversity and compositional differences of core members of the microbiome, with potential implications for the bacterial pulmonary ecosystem’s stability and function.

BACKGROUND: Dysbiosis during childhood impacts the configuration and maturation of the microbiota. The immaturity of the infant microbiota is linked with the development of inflammatory, allergic, and dysmetabolic diseases. AIMS: To identify taxonomic changes associated with age and GDM and classify the maturity of the intestinal microbiota of children of mothers with GDM and children without GDM (n-GDM). METHODS: Next-generation sequencing was used to analyze the V3-V4 region of 16S rRNA gene. QIIME2 and Picrust2 were used to determine the difference in the relative abundance of bacterial genera between the study groups and to predict the functional profile of the intestinal microbiota. RESULTS: According to age, the older GDM groups showed a lower alpha diversity and different abundance of Enterobacteriaceae, Veillonella, Clostridiales, and Bacteroides. Regarding the functional profile, PWY-7377 and K05895 associated with Vitamin B12 metabolism were reduced in GDM groups. Compared to n-GDM group, GDM offspring had microbiota immaturity as age-discriminatory taxa in random forest failed to classify GDM offspring according to developmental age (OOB error 81%). Conclusion. Offspring from mothers with GDM have a distinctive taxonomic profile related to taxa associated with gut microbiota immaturity.

Hypertension is the leading cause of cardiovascular disease, with over 60% prevalence in older adults, and its control is complex and requires multidisciplinary approaches. The role of the gut microbiome in blood pressure control remains unclear despite reported associations of some specific bacteria involved in the development of hypertension. The aim of this study was to characterize the gut microbiome of older adults and to identify bacteria associated with hypertension control. Patients aged 60 years and older from Mexico City and the metropolitan area, all of whom were receiving antihypertensive treatment, provided a feces sample during a routine medical visit. DNA was extracted from 240 samples using a commercial kit, the V3/V4 region of the 16S gene was sequenced, and metataxonomic analyses were performed using QIIME and R. Bacterial abundance analysis identified a core microbiome in the hypertensive older adults, with an increased abundance of Escherichia-Shigella and a decrease in alpha diversity with increasing age. Ruminococcus UCG-002 , DTU 089, and members of the Lachnospiraceae family were distinctively abundant in controlled hypertension. These bacteria are fiber-fermenting and producers of short-chain fatty acids (SCFAs), and their differential abundance according to hypertension control suggests an intricate interplay among SCFA producers. Our results confirm and expand upon previous reports on the core gut microbiome of older adults, suggesting relevant changes in fiber-fermenting bacteria— Ruminococcus UCG-002 , DTU 089, and members of the Lachnospiraceae family—for hypertension control.