The gut microbiome connects nutrition and human health.

The gut microbiome has an undeniable role in mediating the health effects of the diet, given its ability to co-digest nutrients and influence nutrient signalling to multiple organ systems. As a suboptimal diet is a major risk factor for and contributor to disease, understanding the multidirectional interactions between the food we eat, the gut microbiome and the different body organ systems is crucial from a public health perspective. Indeed, this research area is leading to the refinement of nutritional concepts and strategies to optimize health through diet. In this Review, we provide an update on how dietary patterns and food intake shape gut microbiome features, the mode of action of diet-microorganism interactions on the immune, nervous and cardiometabolic systems and how this knowledge could explain the heterogeneity of dietary responses, and support food-based dietary guidelines and medical and precision nutrition. Finally, we discuss the knowledge gaps and research efforts needed to progress towards the integration of microbiome science with more precise dietary advice to leverage the role of nutrition in human health.