The relationship between small intestinal bacterial overgrowth and constipation in children - a comprehensive review

Abstract

Small intestinal bacterial overgrowth (SIBO) is characterized by an increase in the bacterial population of the small intestine due to an imbalance between the amount of bacteria and the intestinal barrier. Pediatric SIBO presents with a wide spectrum of symptoms, ranging from mild gastrointestinal complaints to malabsorption or malnutrition. Breath tests are commonly used as noninvasive diagnostic tools for SIBO, but a standardized methodology is currently unavailable. Intestinal flora produces methane which slows intestinal transit and increases the contractile activity of small intestine. Emerging literature suggests a correlation between overgrowth of methanogenic bacteria in the intestines and constipation. Treatment of SIBO involves administration of antibacterial therapy in addition to management of underlying conditions and optimal dietary adjustments. However, research on antibiotic treatment for pediatric patients with constipation and SIBO is limited and has yielded conflicting results. In the current review, we summarize the state-of-the-art of the field and discuss previous treatment attempts and currently used regimens for SIBO patients with constipation, with a focus on pediatric populations.

Keywords: children; constipation; functional gastrointestinal disorders; irritable bowel syndrome; small intestinal bacterial overgrowth (SIBO).

Figure 1

Flow diagram of studies assessed and included in the review. (n, number).

Figure 2

SIBO prevalence in children with functional gastro-intestinal disorders. The majority of studies did not include a control group.

Figure 3

Small intestinal bacterial overgrowth (SIBO) in relation to childhood constipation: diagnostic and treatment opportunities. Created with BioRender.com (https://biorender.com/) Small intestinal bacterial overgrowth (SIBO) has been linked to functional constipation and irritable bowel syndrome (IBS). The possibility of SIBO depiction through multiple types of breath tests (BTs), such as lactulose BT, hydrogen BT, glucose BT or methane BT leads to miscellaneous results of currently available studies, due to methodology-related disparities. Current treatment options of SIBO include probiotics belonging to the Bifidobacterium genre and Saccharomyces boulardii (S. boulardii), as well as antibiotics, but research on this matter is ongoing. IBS, irritable bowel syndrome; S. boulardii, Saccharomyces boulardii; SIBO, small intestinal bacterial overgrowth.