Is small intestinal bacterial overgrowth involved in the pathogenesis of functional dyspepsia?

Functional dyspepsia is a highly prevalent disease, with significant impacts on patients' quality of life and economic robustness of health care systems worldwide. It constitutes a constellation of symptoms located in the gastro duodenal region while its pathogenesis remains poorly understood. Accumulating evidence suggest that small intestinal bacterial overgrowth is associated with the etiology of functional gastrointestinal disorders. We herein present the hypothesis that a causal link between small intestinal bacterial overgrowth and functional dyspepsia might exist. Development of functional dyspepsia symptoms may derive from abnormal fermentation of carbohydrates due to increased proliferation of coliform bacteria, resulting in luminal distension, increased intestinal permeability and immune response perpetuation in predisposed hosts, secondary to an episode of infectious gastroenteritis. Moreover, the treatment of functional dyspepsia remains challenging and we explore the feasibility of innovative therapeutic modalities based on our hypothesis.