CPT1A and type 2 diabetes mellitus: This result indicates that Lachnospiraceae_bacterium can affect the expression of PPAR signaling pathway-related DEGs (including Hmgcs2, Scd4, Slc27a1, Cpt1a, Plin5, and Plin4) through organic acids (especially 6-hydroxyhexanoic acid, butyric acid, and Sumiki’s acid), thereby contributing to a hypoglycemic effect and inhibiting myocardial injury in T2DM.