Chapter 18 - Pyroglutamyl peptides in Japanese fermented foods and protein hydrolysate enhance production of host-antimicrobial peptides and ameliorate microbial imbalance

Abstract

Humans live with several microorganisms on and in the body. The community of microorganisms is referred to as the microbiota. Gut microbiota can affect human health. Disturbance of gut microbiota, referred to as dysbiosis, is associated with inflammatory bowel disease and metabolic syndrome–related diseases. Short-chain pyroglutamyl peptides, such as pyroglutamyl–leucine (pyroGlu-Leu) and related peptides in traditional Japanese seasonings, salted fermented soy paste (miso), soy sauce (shoyu), and rice wine (sake), and food protein hydrolysates have been demonstrated to attenuate colitis and dysbiosis in animal models after oral administration at 0.1–1.0mg/kg body weight, which were less than the doses of prebiotics and probiotics exerting a similar effect. PyroGlu-Leu–modulated gut microbiota by increasing secretion of host antimicrobial peptides classified as α-defensin in rats. The pyroglutamyl peptide is not generated by the ingestion of normal food proteins. Consumption of Japanese-fermented seasonings from daily dishes and food protein hydrolysate as a supplement can improve gut microbiota and human health.