Elevated levels of circulating short-chain fatty acids and bile acids in type 2 diabetes are linked to gut barrier disruption and disordered gut microbiota.

Aims: Studies have shown that destruction of the intestinal barrier in type 2 diabetes (T2D) leads to increased absorption of macromolecules from intestinal. We previously exhibited that short-chain fatty acids (SCFAs) and bile acids (BAs) were significantly decreased in faeces of T2D patients. In the current study, we extended these findings by focusing on the interactions between intestinal barrier and clinical characteristics, gut microbiota, SCFAs and BAs.

Methods: 65 T2D patients and 35 healthy controls were recruited, targeted metabolomics was used to evaluate the SCFAs and BAs in their serum samples. The serum zonula occludens-1 (ZO-1) was measured by ELISA to evaluate intestinal barrier.

Results: Compared with the healthy controls, the serum concentrations of total SCFA, acetate and propionate were significantly increased in the T2D patients, and certain BAs were also significantly increased. In addition, the higher levels of serum ZO-1 suggested a "leaky gut" in T2D patients. The ZO-1 was comprehensively correlated with clinical characteristics, gut microbiota, SCFAs and BAs.

Conclusion: SCFAs and BAs were excessively absorbed from the intestinal through the leaky gut, leading to higher levels of circulating SCFAs and BAs in T2D patients, and that the leaky gut might be caused by the disordered gut microbiota.