SIBO: Diagnostics, treatments, and current approaches

Abstract

Small intestinal bacterial overgrowth (SIBO) is a disorder of the gut microbiota characterized by an excessive and/or abnormal proliferation of bacteria or archaea within this segment of the gastrointestinal tract, with significant clinical implications. The development of SIBO is multifactorial and involves alterations in intestinal motility, disruption of the epithelial barrier, and the presence of comorbidities such as celiac disease, liver cirrhosis, inflammatory bowel diseases, or chronic use of proton pump inhibitors. Clinical diagnosis is often challenging due to the nonspecific nature of symptoms. Breath tests using glucose or lactulose are the most commonly employed methods, although their reliability is limited. Complementary techniques such as jejunal aspirate cultures, blood tests, and stool analysis can enhance diagnostic accuracy. SIBO treatment must be individualized. Antibiotics – particularly rifaximin, and in cases of IMO (intestinal methanogen overgrowth), in combination with neomycin – have shown significant clinical efficacy. The inclusion of probiotics and prebiotics may help alleviate symptoms, although the supporting evidence is limited. Additionally, low-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) diets have demonstrated symptomatic benefits, provided they are applied temporarily and under supervision to prevent nutritional deficiencies. SIBO management should be comprehensive and personalized, combining accurate diagnostic strategies with tailored therapeutic interventions that integrate antibiotics, nutritional support, and microbiota modulators.