2020 IL- 21 and IL-22 in Type1 Diabetes Patients: role in the Pathogenesis and Regulation of GUT Microbiome

Abstract

n increasing number of models for T1DM have considered the potential role of microbiota, with particular emphasis of those harbored in the gut, as an important factor in the pathogenesis of T1DM. Interleukin (IL)-21 is a type 1 cytokine that is mainly produced by activated T lymphocytes, particularly the inflammatory Th17, subset and has been implicated in the pathogenesis of T1DM. IL-22 is produced by immune cells present beneath the epithelium and is induced by bacteria present in the intestine. It exerts essential roles in maintaining mucosal barrier integrity within the intestine. IL-22 shows diverse metabolic benefits, as it improves insulin sensitivity, preserves gut mucosal barrier and endocrine functions, decreases endotoxaemia and chronic inflammation, and regulates lipid metabolism in liver and adipose tissues. Probiotics are live micro-organisms that, when administered in adequate amounts, confer health benefits on the host. Daily probiotic treatment was found to reduce the expression of proinflammatory cytokines. Probiotics have been found to have a wide application in diseases such as autoimmune, inflammatory, and allergic conditions. The efficacy of probiotics in diabetes has been proven by their ability to lower fasting glucose and insulin levels in a preclinical setting as well as in human trials.