Gut microbiome differences among Mexican Americans with and without type 2 diabetes mellitus

Abstract

Purpose Type 2 diabetes mellitus (T2DM) is an urgent public health problem and disproportionately affects Mexican Americans. The gut microbiome contributes to the pathophysiology of diabetes; however, no studies have examined this association in Mexican-Americans. The objective of this study was to compare gut microbiome composition between Mexican-Americans with and without T2DM. Methods This was a cross-sectional study of volunteers from San Antonio, TX. Subjects were 18 years or older and self-identified as Mexican American. Subjects were grouped by prior T2DM diagnosis. Eligible subjects attended a clinic visit to provide demographic and medical information. Thereafter, subjects recorded their dietary intake for three days and collected a stool sample on the fourth day. Stool 16s rRNA sequences were classified into operational taxonomic units (OTUs) via the mothur bayesian classifier and referenced to the Greengenes database. Shannon diversity and bacterial taxa relative abundance were compared between groups using the Wilcoxon rank sum test. Beta diversity was estimated using Bray-Curtis indices and compared between groups using PERMANOVA. Results Thirty-seven subjects were included, 14 (38%) with diabetes and 23 (62%) without diabetes. Groups were well-matched by body mass index and comorbid conditions. Shannon diversity was not significantly different between those with and without T2DM (3.26 vs. 3.31; p = 0.341). Beta diversity was not significantly associated with T2DM diagnosis (p = 0.201). The relative abundance of the most common bacterial phyla and families did not significantly differ between groups; however, 16 OTUs were significantly different between groups. Conclusions Although alpha diversity was not significantly different between diabetic and non-diabetic Mexican Americans, the abundance of certain bacterial taxa were significantly different between groups.

Review of the Gut Microbiota Dynamics in Type-2 Diabetes Mellitus (T2DM): A Focus on Human-Based Studies

“…59 Microbial taxa, including Prevotella, Coprococcus, Ruminococus, Akkermansia, Faecalibacterium, Roseburia, Eubacterium, Clostridium, Bacteroides, Streptococcus, Propionibacterium, Lactobacillus, and Fusobacterium are primarily responsible for these metabolites. 3,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]56 Unfortunately, our investigations revealed that most of these microbial communities were reduced in patients with T2DM. In healthy patients, while SCFAs directly serve as energy sources to intestinal mucosal cells, they can be circulated systematically, providing a vital host energy source and acting in signal transduction.…”

“…Additionally, we observed that Fusobacteria and Verrucomicrobia were two minor but important phyla. 3,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] On the basis of phylum distribution, however, patients with/without T2DM exhibited conflicting microbiota findings, including increased opportunistic pathogens and decreased butyrateproducing microbes (Table 1). While we observed a rise in Lactobacillus, Akkermansia was reduced in T2DM patients but significantly high in pre-diabetic patients.…”

Association between gut microbiota and prediabetes in people living with HIV

“…Previous works reported that the alpha diversity of gut microbiota was lower in patients with T2DM and prediabetes ( Lambeth et al., 2015 ; Li et al., 2020 ). However, alpha diversity was not significantly different in patients with T2DM and without diabetes in a study conducted in Mexican Americans ( Kitten et al., 2021 ). Another study showed a decreased alpha diversity in patients with newly diagnosed diabetes, but not in those with prediabetes, when compared with those without diabetes ( Gaike et al., 2020 ).…”

Short-Chain Fatty Acids in the Microbiota–Gut–Brain Axis: Role in Neurodegenerative Disorders and Viral Infections

“…Technologies such as 16S rRNA sequencing and shotgun metagenomic sequencing have enabled the study of the composition of GI microbiome and variations of this composition among individual host organisms. ,, α- (within sample) and β- and γ-diversity (between two samples) metrics reflect similarities and/or differences in the “core” microbial composition of the GI habitat in health and disease contexts. − Microbial diversity exploration in CNS disorders has also begun. − A few pioneering studies began investigating the impact of GIM on neurochemistry, where changes in the microbiota led to changes in behavior and neurochemical mediators in animal models. Heijtz et al demonstrated that early life microbiota exposure (within the first 6 weeks) had life-long behavioral and brain developmental impact.…”