Inulin-Type Fructan Supplementation and Glycaemic Control in Patients with Type 2 Diabetes Mellitus: A Randomized Controlled Trial

Abstract

Background: Inulin-type fructans (ITFs) are fermentable dietary fibres proposed to improve glycaemic control in type 2 diabetes
mellitus (T2DM) through gut microbiota-mediated mechanisms. Objective: To synthesise RCT and meta-analytic evidence on ITF supplementation and glycaemic outcomes in T2DM. Methods: Narrative review of published randomised trials, systematic reviews and meta-analyses, and mechanistic studies of inulin and oligofructose in T2DM. Findings: Meta-analyses of 9-34 RCTs show ITF supplementation (5-40 g/day, 6-24 weeks) reduces fasting glucose by 0.42-0.60 mmol/L and HbA1c by 0.58-0.69%, with less consistent insulin-resistance effects; benefit is attributed to bifidogenic and short-chain fatty acid mechanisms, though flatulence is common.
Conclusions: ITF supplementation, at doses of approximately 10 g/day sustained for six weeks or longer, produces modest but
reproducible glycaemic benefit in T2DM, warranting confirmation in larger, longer-duration trials.