The lipid content was reduced by 95% by a combination of larvae and microbiota.MCFAs were more rapidly degraded than LCFAs and sterols during BSFL bioconversion.Lipid content is the key driver of microbial community during BSFL bioconversion.BSFL enhance fatty acid β oxidation and biosynthesis of microbiota in the DBW.Corynebacterium, Marinobacter and Brevibacterium are key taxa in lipid degradation.