In addition, changes in the diversity of the intestinal microbiota can worsen or improve insulin resistance and therefore type 2 diabetes (T2D) in mice and patients [33,34], possibly due to interaction with innate immune signaling through the TLR4, NOD1/NOD2 proteins, etc., as yet undefined pathways [35,36]. This evidence concerns the gene NOD1 and type 2 diabetes mellitus.