The gut–brain axis in irritable bowel syndrome and inflammatory bowel disease.
Angela Ancona et al.
Introduction
Gut microbiota (GM) has a critical role on host health accounting for bacteria, virus, archea, fungi, yeasts, parasite and phages [1]. Over the last twenty years, the research on gut microbiota has focused on bacterial components [2]. The majority of these bacteria belong to two main phyla, Bacteroidetes and Firmicutes, followed by Proteobacteria, Actinobacteria and Fusobacteria [3], and their amounts change on the basis of age, host genetics, diet, use of antibiotics or other drugs and local environment, like oxidative stress [4,5]. Several bacterial compounds can modulate brain functions: molecules released into the gut lumen in response to psychological stress can result in an altered intestinal permeability and gastrointestinal motility, therefore changing the gastrointestinal environment and consequently microbiome composition [6–8]. Early life perturbations of gut microbiome can influence neurodevelopment and potentially lead to unfavorable morbidity effects during adulthood [9,10].
