Diet, the Gut Microbiome and Cardio‐Metabolic Risk

Abstract

The gut microbiome has been implicated as a potential mediator of diet‐related effects on cardio‐metabolic risk. There is evidence to suggest that diet can alter human physiology and disease risk by influencing the composition and activity of the gut microbiota, via mechanisms that may include the production of short chain fatty acids, bile acid deconjugation and polyphenol metabolism. There is substantial variation in the microbiota, with greater variation in fecal bacterial composition between individuals than within an individual, a finding that might underlie variance in the expression of risk factors for chronic diseases.This presentation will examine evidence that dietary modification of cardio‐metabolic risk is mediated, in part, through the gut microbiome. It will address the impact of dietary fatty acids, carbohydrates, prebiotics in novel functional foods, and increased consumption of fruits and vegetables on the gut microbiome and metabolic risk in randomized controlled trials (RCT).The ‘RISCK’ study was a multi‐centred RCT which was designed to evaluated the impact of the amount and quality of dietary fat and carbohydrate on cardio‐metabolic risk in a population at risk of metabolic syndrome. Low fat, high carbohydrate diets increased fecal Bifidobacterium, and reduce fasting glucose and cholesterol. Diets containing high glycaemic index carbohydrates also increased fecal Bacteroides, while high carbohydrate low glycaemic index diets increased Faecalibacterium prausnitzii. In other studies, a high intake of fermentable fibre and plant polyphenols were shown to regulate microbial activities within the gut. In conclusion, these findings provide further evidence for the impact of diet on the gut microbiome, the significance of these effects on cardio‐metabolic risk remain to be confirmed.