In the last few decades, many people have become aware that following a certain dietary habit is an important health concern as it has been linked to weight gain and associated metabolic diseases. The human gastrointestinal tract is the home for trillions of bacteria that are continuously shaped by different factors and amongst these factors is the particular dietary habit followed. In many countries the most common dietary habits followed by many people are vegan, vegetarian, gluten free, ketogenic, high sugar, low-FODMAP, Western-type and Mediterranean diets. In most cases, people follow these diets to maintain a healthy lifestyle or reduce the symptoms of a particular disease, for example as gluten free diet for treating Celiac Diseases and low-FODMAP for treating irritable bowel syndrome. However, the effect of these different diets on the gut microbiota development are still largely unknown, and could potentially lead to alterations of the gut microbiota, the intestinal barrier, and the immune system.

In a recent review study, Rinninella et al, aimed to define the optimal dietary habit for the optimal gut microbiota structure and function. The authors concluded that: