Impact of Combined Prebiotic Galacto-oligosaccharides and Bifidobacterium breve Derived Postbiotic on Gut Microbiota and HbA1c in Prediabetic adults: A Double-blind, Random-ized, Placebo-Controlled Study

The complex interactions between intestinal microbiota and metabolic disorders are well-documented, with implication for glucose metabolism, energy expenditure, and intestinal permeability. Prebiotics induce beneficial changes in gut microbiota composition in prediabetes, while postbiotics can enhance gut barrier function, complementing each other to improve glucose metabolism and insulin sensitivity. This study investigated the effects of a 12-week dietary fiber (DF) supplement on gut health, metabolic function, and diet. The supplement contained konjac glucomannan (KGM), galacto-oligosaccharides (GOS) and exopolysaccharides (EPS) from Bifidobacterium breve. In a randomised, double-blind, placebo-controlled, parallel-group clinical trial, 53 pre-diabetic volunteers were randomly assigned to either a daily DF supplement (YMETA) or a placebo (maltodextrin) for 12 weeks, followed by a 4-week follow-up. Measure-ments included gut microbiota composition, glycated hemoglobin (HbA1c), fasting plasma glu-cose (FPG), plasma lipids, anthropometry, body composition, blood pressure, and dietary intake. The intervention group showed a significant increase in alpha-diversity and butyrate-producing bacteria, with reductions in HbA1c and FPG levels below prediabetes thresholds. No significant changes were observed in the placebo group. This study suggests that manipulating the human gut microbiome through dietary interventions could be a promising therapeutic approach to manag-ing prediabetes and preventing or delaying diabetes.