A Randomised Crossover Trial: The Effect of Inulin on Glucose Homeostasis in Subtypes of Prediabetes

Abstract

Background: Fermentable carbohydrates (FCHO) have been shown to improve insulin sensitivity in normoglycaemic and insulin-resistant subjects. However, there are no data on subjects with prediabetes. We aimed to investigate the effect of the FCHO inulin, on glucose homeostasis in subjects with prediabetes. Methods: In a double-blind and placebo-controlled crossover study, 40 volunteers with prediabetes were randomly allocated to take 30 g/day of inulin or cellulose for 2 weeks in a crossover trial, following a 4-week dose-escalation run-in. Fasting insulin and glucose were measured for all subjects. Fifteen of the 40 subjects also underwent a meal tolerance test to assess insulin sensitivity, free fatty acids and glucagon-like peptide-1 concentrations. A subanalysis was carried out to examine any differences between the prediabetes subtypes. Results: Inulin was associated with a significant increase in _{(0-30 min)}incremental AUC (iAUC) for insulin (treatment: p < 0.04) and _{(0-60 min)}iAUC for insulin (treatment: p < 0.04) compared to control. There was a significant reduction in insulin resistance measured by the homeostatic model assessment in the isolated-impaired fasting glucose (p < 0.05) but not in the isolated-impaired glucose tolerance groups (p = 0.59). Conclusion: The FCHO, inulin, may have unique metabolic effects that are of particular benefit to people at risk of diabetes, which warrant further investigation.

Inulin-type fructan improves diabetic phenotype and gut microbiota profiles in rats

“…A recent meta-analysis showed that inulin-type fructans reduce fasting blood glucose in T2D patients ( Liu et al, 2017 ). Moreover, in pre-diabetic subjects, inulin moderated insulin resistance in an impaired fasting blood subgroup ( Guess et al, 2016 ). A combined supplement of inulin and fiberol-2 (another type of soluble dietary fiber) induced in a reduction in blood lipids in hamsters with hyperlipidemia ( Huang et al, 2016 ).…”

Ectopic Fat Accumulation in Distinct Insulin Resistant Phenotypes; Targets for Personalized Nutritional Interventions

“…On the contrary, the individuals with higher insulin sensitivity were more susceptible to the detrimental effects of SFA. Furthermore, Guess et al ( 141 ) recently reported that 6 weeks of supplementation with the dietary fiber inulin (30 g/d) decreased HOMA-IR in IFG but not in IGT individuals. These results may indicate that inulin has beneficial effects in subjects with liver-IR rather than muscle-IR, as IFG individuals have often a more pronounced liver-IR.…”

Role of Gut Microbiota-Generated Short-Chain Fatty Acids in Metabolic and Cardiovascular Health

“…In overweight/obese men, colonic infusions of SCFA appear to increase fat oxidation, energy expenditure and PYY release, and decrease adipose tissue lipolysis [ 43 ]. Inulin, a fructo-oligosaccharide prebiotic NDC which is readily fermented producing SCFA, has demonstrated beneficial effects on adiposity [ 44 ] substrate metabolism [ 45 ], insulin sensitivity [ 46 ] and appetite regulation [ 47 – 49 ] although the effects seen in humans are inconsistent and may be related to the levels of inulin intake [ 50 ]. A recent meta-analysis tentatively concluded that inulin-type fructans elicit a beneficial effect on lipid profiles and glucose metabolism [ 51 ].…”