Efficacy of an Irritable Bowel Syndrome Diet in the Treatment of Small Intestinal Bacterial Overgrowth Treatment: A Narrative Review

Introduction: Small Intestinal Bacterial Overgrowth (SIBO) is highly prevalent in Irritable Bowel Syndrome (IBS). An eradication of bacterial overgrowth with antibiotics is the first-line treatment. However, focusing only on the antimicrobial effect, without taking care to improve lifestyle factors, especially dietary patterns, may not yield satisfactory results and may even predispose to intestinal microbiota dysfunction. Aim: The objective of this study is to determine whether the current recommendations regarding nutrition in IBS are suitable for patients with SIBO. Methods: A narrative literature review was carried out using databases including PubMed, ScienceDirect and Google Scholar to investigate the current recommendations regarding the necessary elements of lifestyle and nutrition therapies in SIBO treatment. Results: Recent studies indicate that dietary manipulation may have a role in alleviating SIBO gastrointestinal symptoms. A low FODMAP-diet proposed for IBS may regulate symptoms of the digestive system, but there is no reliable data to determine whether this specific elimination diet will be effective in patients with SIBO. Long-term reduction of prebiotics (FODMAPs) may result in unfavorable changes in the composition of the gut microbiota, promoting dysbiosis. Supplementation with soluble fiber can alleviate the symptoms of diarrhea and constipation in IBS and SIBO. Targeted probiotic therapy with the use of well-characterized microbial strains may increase the effectiveness of antibiotic treatment, regulate bowel movements and improve the quality of life of patients with disturbed intestinal microbiota. In patients with SIBO a lower frequency of migrating motor complex (MMC) is acknowledged, which are responsible for cleansing the gastrointestinal tract from food debris and excess bacteria. Therefore optimal dietary patterns play a key role in the treatment of SIBO. Conclusions: Based on currently available literature, the potential efficacy of the IBS diet in SIBO is largely hypothetical. Future research is needed to characterize a specific diet for the treatment of SIBO.