Alternative Treatment Approaches to Small Intestinal Bacterial Overgrowth: A Systematic Review

Broad-spectrum antibiotics are the first-line treatment for small intestinal bacterial overgrowth (SIBO). However, many antibiotics have a considerable side-effect profile and SIBO commonly reoccurs after successful eradication with antibiotics. Alternative therapies such as probiotics, therapeutic diets, and herbal medicines have been used to individualize SIBO management, particularly in recalcitrant cases. The objective of this review is to evaluate the role of alternative therapies in SIBO treatment. EMBASE, MEDLINE, and the Cochrane Central Register were systematically searched for clinical studies evaluating alternative therapies in the management of SIBO. Human studies in which an alternative intervention was used to treat SIBO were included. Alternative interventions were defined as an intervention that included a probiotic supplement, herbal preparation, or a dietary change. Randomized controlled trials (RCTs), nonrandomized clinical trials with or without a control, and crossover studies were included. The following information was extracted from the selected studies: study type, study participants, SIBO subtype, intervention, comparison, outcome measures, relevant results, relevant side effects, and Jadad score. Eight studies met inclusion criteria. The studies evaluated probiotics (n = 5), therapeutic diet (n = 1), and herbal medicines (n = 2). Among these studies, there were four RCTs, two open-label single-arm studies, one randomized, double-blind crossover study, and one two-arm open-label study with crossover. Main results are summarized. There may be studies not captured by the defined search criteria. Additionally, studies used different methodologies in both breath testing and measurement of clinical symptoms, making it difficult to draw conclusions on SIBO eradication and symptom improvement across studies. Our findings suggest preliminary evidence for a role of alternative therapies in the treatment of SIBO. However, robust clinical trials are generally lacking. Existing studies tend to be small and lack standardized formulations of treatment. Breath testing protocols and clinical symptom measurement greatly varied between studies. Large-scale, randomized, placebo-controlled trials are needed to further evaluate the best way to utilize alternative therapies in the treatment of SIBO.