Pyroglutamyl leucine, a peptide in fermented foods, attenuates dysbiosis by increasing host antimicrobial peptide

Saki Shirako; Yumi Kojima; Naohiro Tomari; Yasushi Nakamura; Yasuki Matsumura; Kaori Ikeda; Nobuya Inagaki; Kenji Sato

doi:10.1038/s41538-019-0050-z

Pyroglutamyl leucine, a peptide in fermented foods, attenuates dysbiosis by increasing host antimicrobial peptide

NPJ Sci Food. 2019 Oct 7:3:18. doi: 10.1038/s41538-019-0050-z. eCollection 2019.

Authors

Saki Shirako¹, Yumi Kojima¹, Naohiro Tomari², Yasushi Nakamura³, Yasuki Matsumura⁴, Kaori Ikeda⁵, Nobuya Inagaki⁵, Kenji Sato¹

Affiliations

¹ 1Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Kyoto 606 8502 Japan.
² 2Kyoto Municipal Institute of Industrial Technology and Culture, 91 Chudouji Awata-cho, Kyoto, 600 8813 Japan.
³ 3Department of Japanese Food Culture, Kyoto Prefectural University, Shimogamo-Hangi-cho, Kyoto, 606 8522 Japan.
⁴ 4Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto, 611 0011 Japan.
⁵ 5Department of Diabetes, Endocrinology and Nutrition, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Kyoto, 606 8507 Japan.

Abstract

PyroGlu-Leu is present in certain food protein hydrolysates and traditional Japanese fermented foods. Our previous study demonstrated that the oral administration of pyroGlu-Leu (0.1 mg/kg body weight) attenuates dysbiosis in mice with experimental colitis. The objective of this study was to elucidate why such a low dose of pyroGlu-Leu attenuates dysbiosis in different animal models. High fat diet extensively increased the ratio of Firmicutes/Bacteroidetes in feces of rats compared to control diet. Oral administration of pyroGlu-Leu (1 mg/kg body weight) significantly attenuated high fat diet-induced dysbiosis. By focusing on the production of intestinal antimicrobial peptides, we found that pyroGlu-Leu significantly increased the level of 4962 Da peptides, which identified as the propeptide of rattusin or defensin alpha 9, in ileum. We also observed increased tryptic fragment peptides from rattusin in the lumen. Here, we report that orally administered pyroGlu-Leu attenuates dysbiosis by increasing in the host antimicrobial peptide, rattusin.

Keywords: Nutrition; Peptides.