Análisis metagenómico de la microbiota gástrica de ratones con diabetes mellitus tipo 2 inducida

Abstract

This research arises in response to the increasing prevalence of type 2 diabetes mellitus in Ecuador and the growing evidence linking the gastrointestinal microbiota with metabolic diseases. Unlike the intestinal microbiota, the gastric microbiota has been scarcely explored, despite its involvement in early digestion, local immune regulation, and the initial interaction with diet and drugs. In this context, the gastric bacterial community of healthy and diabetic BALB/c mice fed a high-carbohydrate diet was characterized, comparing animals without supplementation and animals receiving a commercial probiotic. Gastric content was processed for metagenomic DNA extraction and sequencing of the V3–V4 region of the 16S rRNA gene. Bioinformatic analysis using tools such as QIIME2 allowed the estimation of alpha and beta diversity indices, as well as relative abundances and taxonomic profiles. The communities were dominated by the phyla Bacillota and Bacteroidota, with a predominance of the genus Lactobacillus in all groups and additional enrichment of Bifidobacterium in supplemented animals. The Shannon and Chao1 indices showed a trend toward greater diversity and richness in the diabetic group receiving probiotics, whereas the Simpson index remained stable, indicating similar evenness among communities. Beta-diversity analyses using NMDS and PCoA revealed a partial separation between supplemented and non-supplemented diabetic mice. In summary, the results suggest that diabetes modifies the structure of the gastric microbiota and that probiotic supplementation promotes a more diverse and potentially protective microbial profile.