A comparative study of the effects of different types of dietary fiber on gut microbiota metabolites and insulin sensitivity in diabetic patients

Abstract

This study examined how soluble and insoluble fibers affect blood sugar control, gut bacteria, and intestinal health in mice with type 2 diabetes. Thirty C57BL/6J mice were divided into three groups: diabetic control, inulin-fed, and wheat-bran-fed. After 12 weeks, fasting glucose dropped by 31% and HOMA-IR by 45% in the inulin group, while the wheat bran group showed smaller drops of 18% and 20%. Analysis of metabolites showed that inulin raised butyrate and lactate levels, while wheat bran increased propionate and valerate. The inulin group also had about 60% higher Occludin protein levels (P < 0.01), showing better gut barrier function. These results show that soluble fiber improves insulin response by supporting short-chain fatty acid formation and maintaining gut integrity, while insoluble fiber works mainly through slower fermentation. The study shows that fiber type plays an important role in managing blood sugar, offering evidence for choosing the right kind of fiber to support diabetes care.