Efficacy of a Diet and Lifestyle Modification Program on Biomarkers of Metabolic Health and the Gut Microbiota Composition in Healthy Overweight Adults

Objectives: The primary objective of this study was to examine the effect of a specific dietary and lifestyle modification program (AstonRx Program; this included time-restricted eating, nutritional fasting, education, support and strength-based exercise) on biomarkers of metabolic and gut health in healthy overweight adults over 4 weeks in a randomised, double-blind, placebo-controlled trial. Methods: Sixty-nine overweight participants (BMI 25-29.9 kg/m2) were randomly assigned to four groups: Group A received a novel dietary fibre (NDF) supplement along with lifestyle modification & dietary advice (LDMA); Group B received only the novel dietary fibre supplement; Group C received psyllium together with LDMA and Group D, the control, received a placebo. Biomarkers of metabolic health, including body weight, BMI, body fat, glucose and lipid profiles, and inflammatory markers were assessed before and after the intervention. Stool samples collected before and at the end of the intervention were examined to determine the composition of gut microbiota by 16S rRNA gene sequencing and the relationship between specific taxa and risk factors of metabolic health. Results: The results showed that participants who received LDMA including either psyllium (AstonRx Program) or NDF exhibited a significant reduction in body weight, BMI, body fat mass and biomarkers of liver and kidney function post-intervention, compared with the same groups pre-intervention and the controls. A significant reduction in CRP (and non-significant reductions in the fasting insulin levels and HOMA-IR score) in subjects receiving DLMA with psyllium, and significant reductions in cholesterol and LDL in subjects receiving DLMA with NDF or just NDF alone, were also observed. Analysis of stool samples of subjects with improved outcomes showed distinct shifts in gut microbial composition and diversity. Conclusions: These results demonstrate the favourable impact of DLMA for improving metabolic health in overweight subjects and highlight the potential for developing personalized dietary and lifestyle recommendations to improve metabolic health in at-risk subjects. Funding Sources: The study was funded by an Innovation Connections Grant from the Australian Government with co-contribution from Aston Rx Pty Ltd.