Dietary Bioactive Peptide Alanyl-Glutamine Attenuates Dextran Sodium Sulfate-Induced Colitis by Modulating Gut Microbiota.

Abstract

Inflammatory bowel disease (IBD) is a chronic intestinal disorder threatening human health. Di-peptide alanyl-glutamine (Ala-Gln) has various beneficial effects on gut health. However, its role and functional mechanism in treating IBD are still not clear. Therefore, the protective effects of Ala-Gln and glutamine (Gln) on dextran sulfate sodium- (DSS-) induced colitic mice were investigated in this study. The results showed that oral supplementation of Ala-Gln or Gln significantly attenuated the colitis symptoms in mice, including body weight loss, colon length, disease activity index, histological scores, and tissue apoptosis. The concentrations of interleukin- (IL-) 1β, IL-6, tumor necrosis factor-α, and myeloperoxidase were significantly decreased, while the concentrations of immunoglobulins (IgA, IgG, and IgM) and superoxide dismutase were significantly increased by Ala-Gln or Gln supplementation. The expression of occludin and peptide transporter 1 (PepT1) was significantly increased by Ala-Gln or Gln. Interestingly, Ala-Gln had better beneficial effects than Gln in alleviating colitis. In addition, 16S rDNA sequencing showed that the DSS-induced shifts of the microbiome (community diversity, evenness, richness, and composition) in the mouse colon were restored by Gln and Ala-Gln, including Lactobacillus, Bacteroides_acidifaciens, Bacteroidales, Firmicutes, Clostridia, Helicobacter, and Bacteroides. Correspondingly, the functions of the microflora metabolism pathways were also rescued by Ala-Gln, including fatty acid metabolism, membrane transporters, infectious diseases, and immune system. In conclusion, the results revealed that Ala-Gln can prevent colitis through PepT1, enhancing the intestinal barrier and modulating gut microbiota and microflora metabolites.

• Authors: Qingbiao Xu, Mingyang Hu, Min Li, Jinxiu Hou, Xianghua Zhang, Ya Gao, Bahram Chachar, Xiang Li
• Journal: Oxidative medicine and cellular longevity (Oxid Med Cell Longev) Vol. 2021 Pg. 5543003 ( 2021) ISSN: 1942-0994 [Electronic] United States
• PMID: 34046146 (Publication Type: Journal Article)
• Copyright: Copyright © 2021 Qingbiao Xu et al.

Chemical References

• Dipeptides
• Sulfates
• sodium sulfate
• alanylglutamine

Topics

• Animals
• Colitis (etiology, physiopathology)
• Dipeptides (metabolism)
• Gastrointestinal Microbiome (immunology)
• Humans
• Inflammatory Bowel Diseases
• Male
• Mice
• Sulfates (adverse effects)