CFD protein deficiency induce slow transit constipation is correlated with gut microbial dysbiosis.

Dysregulation of complement factor D (CFD) has been associated with various diseases, such as metabolic, cardiovascular, and renal disorders. However, its role in intestinal function has been less studied. Our research found that CFD-deficient (Cfd–/–) mice exhibited spontaneous slow transit constipation (STC) compared to wild-type (WT) mice. Moreover, the fecal weight and water content in Cfd–/– mice were significantly reduced, despite no specific changes in feeding behavior. Reduced C-kit protein expression, colon injury, complement dysfunction and dysbiosis of the fecal microbiota are also observed in Cfd–/– mice. After microbiota transplantation from WT mice into Cfd–/– mice, reduced stool output, water content, decreased C-kit protein expression and colon injury were significantly improved. These results indicate that CFD is critical for controlling microbial homeostasis in the colon and, in its absence, leads to colon injury and promotes slow transit constipation.