High-throughput sequencing results revealed that the intestinal tract of T2D rats was enriched with more gram-negative bacteria, such as Prevotella, Acinetobacter, and Proteus. As a cell wall component of gram-negative bacteria, LPS potently activates the NF-κB signaling pathway via TLR4, while P. distasonis promotes intestinal barrier repair, decreases blood LPS levels, and inhibits the TLR4-NF-κB signaling pathway. This evidence concerns the gene TLR4 and type 2 diabetes mellitus.