The gastrointestinal (GI) tract is colonized by bacteria immediately after birth; Escherichia coli, Streptococci and Clostridi are the first bacteria harboured by the colon, followed by anaerobic Enterococci, Lattobacilli and Bacteroidi. These commensal bacteria inhabiting the human intestine (i.e., intestinal microflora) participate in the development and maintenance of gut sensory and motor functions, including the promotion of intestinal propulsive activity; on the other hand, intestinal motility represents one of the major control systems of gut microflora, though the sweeping of excessive bacteria from the lumen. There is emerging evidence indicating that changes in this bi-directional interplay contribute to the pathogenesis of gut diseases, such as small intestinal bacterial overgrowth (SIBO).
