Abstract Background & objective: Recently, dietary restriction of fermentable carbohydrates (a low-FODMAP diet) in combination with a gluten-free diet (GFD) has been proposed to reduce the symptoms in irritable bowel syndrome (IBS) patients. Different studies reported that IBS has been associated with dysbiosis in the gut microbiota. Additionally, a few studies have reported inflammation in gastrointestinal (GI) system of adults with IBS. In this study we aim to investigate the effects of GFD and low-FODMAP diet on clinical symptoms, intestinal microbiota diversity, and fecal calprotectin (FC) level in Iranian patients with IBS. Design: In this clinical trial study, 42 patients with IBS (Rome IV criteria) underwent GFD + low-FODMAP dietary intervention for 6 weeks. Symptoms were assessed using the IBS symptom severity scoring (IBS-SSS), and fecal samples were collected at baseline and after intervention and analyzed by quantitative 16S rRNA PCR assay. The diversity of gut microbiota compared before and after 6 weeks of dietary intervention. FC was also analyzed by ELISA method. Results: Thirty patients (mean age 37.8 ± 10.7 years) completed the 6-week diet. The IBS-SSS was significantly ( P = 0.038) reduced after GFD + low-FODMAP dietary intervention compared to the baseline. Significant microbial differences before and after intervention were noticed in fecal samples. A significant increase was found in Bacteroidetes , and the Firmicutes to Bacteroidetes (F/B) ratio was significantly ( P = 0.001) decreased after the dietary intervention. The value of FC was significantly decreased after 6 weeks dietary intervention ( P = 0.001). Conclusions: Our study suggests that patients with IBS under a GFD + low-FODMAP diet had a significant improvement in IBS symptoms severity, with reduced FC level following normalization of their gut microbiota composition. Further rigorous trials are needed to establish long-term efficacy and safety of this dietary intervention for personalized nutrition in IBS.
Authors: Kaveh Naseri, Hossein Dabiri, Mohammad Rostami‐Nejad, Abbas Yadegar, Hamidreza Houri, Meysam Olfatifar, Amir Sadeghi, Saeede Saadati, Carolina Ciacci, Paola Iovino, Mohammad Reza Zali
DOI: https://doi.org/10.21203/rs.3.rs-136688/v1
Publish Year: 2021
