The Influence of Small Intestinal Bacterial Overgrowth in Digestive and Extra-Intestinal Disorders

Abstract

Small intestinal bacterial overgrowth (SIBO) is a condition hallmarked by an increase in the concentration of colonic-type bacteria in the small bowel. Watery diarrhea, bloating, abdominal pain and distension are the most common clinical manifestations. Additionally, malnutrition and vitamin (B12, D, A, and E) as well as minerals (iron and calcium) deficiency may be present. SIBO may mask or worsen the history of some diseases (celiac disease, irritable bowel disease), may be more common in some extra-intestinal disorders (scleroderma, obesity), or could even represent a pathogenetic link with some diseases, in which a perturbation of intestinal microbiota may be involved. On these bases, we performed a review to explore the multiple links between SIBO and digestive and extra-intestinal diseases.

Keywords: Parkinson disease; inflammatory bowel disease; irritable bowel syndrome; microbiota; obesity; rheumatology; skin diseases; small intestinal bacterial overgrowth.

Figure 1

Stepwise approach to non-responsive celiac disease and the importance of SIBO recognition in this process.

Figure 2

Role of SIBO and gut microbiota in the pathogenesis of hepatic encephalopathy. Both SIBO and a dysbiosis with low Bacteroidetes and high Proteobacteria and Fusobacteria may contribute to the pathogenesis of HE, by engendering a damage to tight junctions and producing toxins and ammonia which, in turn, worsen HE.