A metagenomic study of the gut microbiome in patients with type 2 diabetes mellitus and myocardial infarction.

OBJECTIVE

This study aimed to investigate gut microbiota composition and metabolic functions in patients with type 2 diabetes mellitus (DM) complicated by myocardial infarction (MI) and to explore potential mechanisms linking the gut microbiome to MI development.

METHODS

Sixty patients with DM complicated by MI and 52 patients with DM alone were initially recruited. After quality control, 29 DM + MI patients and 33 DM patients were included in the final analysis. Gut microbial profiles were characterized using shotgun metagenomic sequencing and bioinformatics analyses. Microbial diversity, composition, and gene functions were compared between groups based on KEGG, COG, and CAZy annotations.

RESULTS

Overall microbial diversity and metabolic profiles were comparable between the two groups; however, significant differences were observed in specific taxa and functional genes. Taxa enriched in the DM + MI group included Bacteroidales, Prevotellaceae, and Lachnospiraceae. In total, 510 KEGG orthology (KO) units and 21 pathways-including ABC transporters, quorum sensing, and general metabolic pathways-differed significantly between groups. Carbohydrate transport and metabolism, as well as glycoside hydrolase activity, represented the most enriched functional categories. Random forest models based on selected microbial species, KO units, and KEGG pathways achieved areas under the curve (AUCs) of 0.868, 0.885, and 0.820, respectively.

CONCLUSION

Patients with DM complicated by MI exhibit distinct gut microbial compositions and functional gene signatures compared with patients with DM alone. These microbiome-based markers may contribute to early risk stratification and provide potential targets for microbiota-focused interventions to mitigate MI risk in patients with diabetes.