Gut microbiome and lipid metabolism: from associations to mechanisms

Purpose of review The gut microbiome has now been convincingly linked to human metabolic health but the underlying causality and mechanisms remain poorly understood. This review focuses on the recent progress in establishing the associations between gut microbiome species and lipid metabolism in humans and discusses how to move from association toward causality and mechanistic understanding, which is essential knowledge to bring the observed associations into clinical use. Recent findings Recent population-based association studies have shown that the gut microbiota composition can explain a substantial proportion of the interindividual variation in blood triglycerides and HDL-cholesterol level and predict metabolic response to diet and drug. Faecal transplantation has suggested that this is a causal effect of microbiome on host metabolism, although the underlying mechanism remains largely unexplored. Summary The gut microbiome is transitioning from being a 'missing' organ to a potential target for therapeutic applications. Due to the complex interplay between the gut microbiome, the host genome, and diet, a systematic approach is required to pave the way for therapeutic development.