An altered gut microbiota is associated with anthropometric and biochemical changes in a prediabetes Mexican cohort

An altered gut microbiota is considered to be an environmental factor contributing to the pathogenesis of various diseases, including metabolic disorders. In this study, we identified changes in the composition of the fecal microbiota of Mexican individuals with prediabetes and analyzed their influences on variables related to this metabolic disorder. Bacterial DNA was extracted from feces of normoglycemic and prediabetes individuals, followed by sequencing of the V4 16S rDNA. Clinical variables were correlated with bacterial abundance and diversity indexes. LEfSe analysis was used to identify relevant bacteria in normoglycemic and prediabetes individuals. Relationships between bacterial clusters and clinical data were assessed with weighted correlation network analysis (WGCNA). Bacterial diversity was positively correlated with anthropometric variables in the control group, while in individuals with prediabetes, it was negatively correlated with the insulin concentration and homeostatic model assessment of insulin resistance (HOMA-IR). We also observed that the microbiota in prediabetes individuals had a higher prevalence of Ralstonia and was enriched with bacteria belonging to the family Lachnospiraceae, as well as Eubacterium biforme and Gemmiger formicilis, while in controls, we found higher abundances of Coprococcus and Bifidobacterium bifidum (abs(linear discriminant analysis (LDA) score) >2). These results identify changes in the microbiota in Mexican adults with prediabetes. Remarkably, the genus Ralstonia was only found in prediabetes individuals. Higher insulin concentrations and HOMA-IR in those individuals were correlated with lower microbiota diversity.