Dietary Supplementation with Inulin Modulates the Gut Microbiota and Improves Insulin Sensitivity in Prediabetes

Abstract

Aims. Accumulating evidence indicates gut microbiota dysbiosis is involved in metabolic disorders, including prediabetes. The prebiotic inulin has been frequently reported to exert beneficial effects on the host metabolism. Here, we aimed to evaluate whether dietary supplementation with inulin modulates gut microbiota structure in prediabetes, affecting glucose and lipid metabolism. Methods. We performed a prospective single-arm study. A total of 49 subjects with prediabetes (WHO 1999 criteria) were voluntarily enrolled. Each subject received a daily supplement with 15 g of inulin for 6 months. Glucose and lipid metabolic parameters and gut microbiota were analyzed at baseline and at 3 and 6 months after inulin intervention. Intestinal microbiota profile was evaluated using the Illumina MiSeq platform based on V3-V4 bacterial 16S rRNA gene. Results. The mean age of 49 subjects was 56.6 ± 6.9 years and BMI was 25.07 ± 3.02 kg/m2. After 24 weeks of prevention, inulin significantly decreased fasting insulin (2.38 ± 0.50 vs. 2.22 ± 0.62, P = 0.03 ) and 2-hour post-OGTT insulin (4.01 ± 0.77 vs. 3.74 ± 0.76, P = 0.02 ) and improved HOMA-IR (1.05 ± 0.53 vs. 0.85 ± 0.66, P = 0.03 ). Gut microbiota analysis indicated that inulin supplement resulted in an increase in the relative abundance of Actinobacteria, Bifidobacteriales, Bifidobacteriaceae, Lactobacillaceae, Bifidobacterium, Lactobacillus, and Anaerostipes both at 3 and 6 months, while with a decrease in the relative abundance of Alistipes. Spearman correlation analysis revealed altered microbial community was associated with glucose and lipids metabolic parameters. Conclusions. Inulin supplementation improves insulin resistance of prediabetes and exerts beneficial effects on modulating the intestinal microbiota composition. These findings suggest that insulin may be a potentially novel and inexpensive intervention for prediabetes.

The Protective Effects of Inulin-Type Fructans Against High-Fat/Sucrose Diet-Induced Gestational Diabetes Mice in Association With Gut Microbiota Regulation

“…Therefore, gut microbiota may also participate in the pathogenesis of several metabolic disorders, such as obesity, diabetes mellitus, and GDM ( Cani et al, 2014 ; Zhang et al, 2015 ; Rowland et al, 2018 ; Cortez et al, 2019 ). Prebiotics can exert positive effects on the maintenance of host metabolic homeostasis, which are mainly mediated by the gut microbiota ( Khanum et al, 2000 ; Wang et al, 2021 ). ITF, one of the crucial prebiotics, have been demonstrated to be effective in the treatment of T2DM ( Dehghan et al, 2014a ; Zhang et al, 2018 ), while data on the effects of symbiotic supplementation on markers of insulin metabolism and lipid concentrations in GDM are scarce.…”

Inulin reduces visceral adipose tissue mass and improves glucose tolerance through altering gut metabolites

“…Previous reports have revealed the effect of inulin supplementation on glucose and lipid metabolism in genetically obese mice [ 11 ], or wild-type mice [ 12 , 13 ] or rats [ 14 ] after induction of dietary obesity. Human studies [ 15 , 16 ] have also shown that inulin intake improves glycolipid metabolism, as it is fermented into SCFAs by gut microbiota in the situation of energy excess due to the high-fat and high-sucrose diet (HFHSD), or in the presence of glucose intolerance or obesity.…”

Supplementation with inulin-type fructans affects gut microbiota and attenuates some of the cardiometabolic benefits of a plant-based diet in individuals with overweight or obesity

“…This is in line with previous studies that found supplementation with inulin and/or FOS does not have significant independent effects on fasting glycemia and insulinemia, HOMA-IR index or lipid profile ( 31–35 ). Nonetheless, others demonstrated that ITF-prebiotics may have lipid-lowering ( 36 ) or glucose-lowering ( 13 , 37 , 38 ) effects, particularly among those with impaired fasting glycemia or hypercholesterolemia. In the present study we recruited individuals with obesity who were otherwise healthy (i.e., without hypertension, glucose abnormalities, and dyslipidemia), and found trends for attenuated reduction in glucose and LDL-C and augmented reduction in HDL-C in the ITF-subgroup relative to control, despite similar weight loss.…”