Effect of a high-collagen peptide diet on the gut microbiota and short-chain fatty acid metabolism

In this study, a total of 24 male Sprague Dawley rats were randomly divided into 3 group (Collagen peptide of Salmon salar skin group, Ss-SCP; Collagen peptide of Tilapia nilotica skin group, Tn-SCP and Model control group, MC) to investigate the impact of a high-collagen peptide diet on the gut microbiota and host health. After 16 days intervention, the body weights of the Ss-SCP and Tn-SCP intervention groups were significantly increased and the liver index was also remarkably higher than that of the MC group. The acetic acid and propionic acid levels in feces were both significantly increased in the diet high-collagen peptide groups and valerate acid level was lower than that in the MC group. With the intervention of a high-dose collagen peptide diet, the gut microbiota of the groups was shifted with increased abundance of Lactobacillus, Unidentified-Prevotellaceae, Allobaculum, and Parasutterella, whereas the Tn-SCP administration have caused low abundance of Anaerostipes, Blautia, and Fusicatenibacter. The relative abundance of Allobaculum as well as Parasutterella was positively correlated with propionic acid and acetic acid levels, respectively. In addition, Allobaculum abundance was negatively correlated with valerate acid level. The serum valerate acid content was potentially harmful to rat health and significantly increased in the groups intervened with collagen peptide. All together, these results showed that administration of diet high-collagen peptide shifts the gut microbiota in rats and induced a disturbance in short-chain fatty acid metabolism which is potentially harmful to health.