Anti-hypertensive and gut microbiota regulatory effects of yeast protein hydrolysate on spontaneous hypertensive rat

This study aims to evaluate the in vivo anti-hypertensive activity and the intestinal microbiota regulation of yeast protein hydrolysate (YH) on spontaneous hypertensive rat (SHR). The YH was produced by alkali protease hydrolysis and ultrafiltration, with the ACE inhibitory IC50 of 0.11 mg/mL. Treatment with 200 mg/kg BW and 400 mg/kg BW of YH resulted in 12 and 17 mmHg of decrease in systolic blood pressure (SBP), respectively, at 4 h after the first administration. For 4-week administration, both dosages of the YH could decrease about 20 mmHg of SBP compared with untreated SHRs. The YH modulated blood pressure by inhibiting serum ACE activity, lowering Ang II content, and upregulating the expression of AT2R at the higher dose. The YH also alleviated oxidative stress in SHRs, significantly elevating serum GSH (24%) and reducing MDA content (50%). In addition, the YH could restore the gut microbiota dysbiosis of SHR, and increased the titer of fecal short-chain fatty acids (SCFAs) as well as the relative abundance of SCFA producing bacteria, including Roseburia, Bacteroides, Ruminococcaceae_UCG-005, Ruminococcaceae_UCG-014 and Alloprevotella. According to the correlation analysis, significant relevances among blood pressure, serum ACE activity, Ang II level, oxidative stress, fecal SCFAs, and gut microbiota in SHR were found. Therefore, YH is a promising functional component in lowering blood pressure and regulating intestinal microbiota.