Plant-based diets (PBDs), rich in high-quality plant foods, offer multiple benefits for the overall and gastrointestinal health. Recently, it has been demostrated that the positive effects of PBDs on gastrointestinal health can be mediated by the gut microbiota, in particular, by inducing a greater diversity of bacteria.

This review summarizes current knowledge on the relationship between nutrition, the gut microbiota, and host metabolic status. We discussed how dietary habits modify the composition and physiological activity of the gut microbiota and how gut dysbiosis affects the most prevalent gastrointestinal diseases, including inflammatory bowel diseases, functional bowel disorders, liver disorders, and gastrointestinal cancer. The beneficial role of PBDs is being increasingly recognized as potentially useful in the management of most diseases of the gastrointestinal tract.