Dietary Alpha‐Ketoglutarate Promotes Epithelial Metabolic Transition and Protects against DSS‐Induced Colitis

• Published in: Molecular nutrition & food research Vol. 65; no. 7; pp. e2000936 - n/a
• Main Authors: Tian, Qiyu, Bravo Iniguez, Alejandro, Sun, Qi, Wang, Hongbin, Du, Min, Zhu, Mei‐Jun
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.04.2021
• Subjects: alpha‐ketoglutarate; Animals; Bleeding; Body weight; Body weight loss; Colitis; Colitis - chemically induced; Colitis - drug therapy; Colitis - metabolism; Colitis - prevention & control; Colon; Colon - drug effects; Colon - metabolism; Colon - physiopathology; Damage; Dextran; Dextran sulfate; Dextran Sulfate - toxicity; Dextrans; Diet; Dietary Supplements; Drinking water; DSS; Energy balance; Enriched foods; Food; Food intake; Glycolysis; Homeostasis; Inflammation; Inflammatory bowel disease; intestinal barrier; Intestine; Intestines - drug effects; Intestines - physiology; Ketoglutaric Acids - blood; Ketoglutaric Acids - pharmacology; Macrophages; Macrophages - drug effects; Macrophages - pathology; Male; Metabolites; Mice; Mice, Inbred C57BL; Molecular modelling; Mucosa; Oxidative metabolism; Signal transduction; Signaling; Weight loss; Wnt protein; Wnt Signaling Pathway - drug effects; DSS; inflammation; intestinal barrier; alpha-ketoglutarate; inflammatory bowel disease
• ISSN: 1613-4125; 1613-4133
• DOI: 10.1002/mnfr.202000936

Scope As a natural compound in foods, alpha‐ketoglutarate (aKG) is one of the key metabolites maintaining energy homeostasis. This study examines the beneficial effects of dietary aKG against the development of experimental colitis and further explores the underlying molecular mechanisms. Methods and Results Eight‐week‐old male C57BL/6 mice receive drinking water with or without 1% aKG for 4 weeks. At week 3, colitis is induced by 2.5% dextran sulfate sodium (DSS) for 7 days followed by 7 days recovery. Dietary aKG supplementation decreases DSS‐induced body weight loss, gross bleeding, fecal consistency score, and disease activity index. In agreement, aKG supplementation restores DSS‐associated colon shortening, ameliorated mucosal damage, and macrophage infiltration into colonic tissue, which are associated with suppressed gut inflammation and Wnt signaling, and improved epithelial structure. Consistently, aKG supplementation enhances M1 to M2 macrophage polarization and strengthens intestinal barrier function. Additionally, aKG supplementation elevates colonic aKG levels while decreasing 2‐hydroxyglutarate levels, which increases oxidative instead of glycolytic metabolism. Conclusion aKG supplementation protects against epithelial damage and ameliorates DSS‐induced colitis, which are associated with suppressed inflammation, Wnt signaling pathway, and glycolysis. Intake of foods enriched with aKG or aKG supplementation can be an alternative approach for the prevention or treatment of colitis that are common in Western societies. Alpha‐ketoglutarate (aKG) is a classic metabolite in tricarboxylic acid cycle and natural compound in foods. Dietary aKG protects dextran sulfate sodium‐induced colitis through inhibiting Wnt signaling, promoting M2 macrophage polarization, and enhancing epithelial barrier function.