Fecal calprotectin concentrations in patients with small intestinal bacterial overgrowth.

Background/Aims. Small intestinal bacterial overgrowth is defined by any condition in which the proximal part of the small bowel harbors for a long time >105 bacteria per ml of the intestinal juice. No data are currently available about direct or indirect parameters indicating the presence of leukocytes in the gut wall and mucosal neutrophils turnover in patients with small intestinal bacterial overgrowth. In our pilot study we evaluate faecal calprotectin concentrations in patients with small intestinal bacterial overgrowth, in order to identify a possible presence of sub-clinical intestinal inflammation. Methods. Forty consecutive patients with small intestinal bacterial overgrowth resulting positive to hydrogen glucose breath test, and forty adult healthy volunteers were included in the study. Faecal calprotectin concentrations were determined by ELISA. Mean faecal calprotectin concentrations were compared by means the t-test for independent samples. Results. Faecal calprotectin concentrations in patients with small intestinal bacterial overgrowth were not significantly different compared to controls (p=0.907). Conclusion. Our study shows for the first time that faecal calprotectin concentrations in patients with small intestinal bacterial overgrowth do not significantly differ from controls, suggesting that in small intestinal bacterial overgrowth there are no intestinal subclinical inflammatory changes involving principally the neutrophils.