The microbiome as a mediator of type 2 diabetes mellitus in Mexican Americans

Access full-text files




Kitten, Amanda Kristine

Journal Title

Journal ISSN

Volume Title



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. 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 T2DM diagnosis. Eligible subjects attended a clinic visit to provide demographic and medical information. Thereafter, subjects recorded what they ate for three days and collected a stool sample on the fourth day. Stool 16s rRNA sequences were classified into operational taxonomic units (OTUs) via Mothur’s Bayesian classifier and referenced to the Greengenes database. Alpha diversity and 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. Thirty-seven subjects were included, 14 (38%) with diabetes and 23 (62%) without diabetes. Groups were well-matched by body mass index (BMI) (diabetes 30 mg/kg2, no diabetes 28 mg/kg2; p=0.4653) and other comorbid conditions. Alpha diversity was not significantly different between those with and without T2DM (3.21 vs. 3.07; p=0.3409). Beta diversity was not significantly associated with T2DM diagnosis (p=0.1249). Sixteen operational taxonomic units (OTUs) were significantly different between groups. There was a significantly lower relative abundance (RA) of Streptococcus in those with T2DM (p=0.04). The Firmicutes to Bacteroidetes ratio was higher in those with T2DM (0.637:1) compared to those without T2DM (0.507:1). In conclusion, although alpha diversity was not different between diabetic and nondiabetic Mexican-Americans, the microbial composition was significantly different


LCSH Subject Headings