Randomised controlled trial: effects of gluten-free diet on symptoms and the gut microenvironment in irritable bowel syndrome.

"data s1 click here for additional data file."

"Declaration of personal interests: Joost P. Algera; Maria K. Magnusson; Stine Störsrud; and Hans Törnblom: none. Lena Öhman has received financial support for research from Genetic Analysis AS, Biocodex, Danone Nutricia Research and AstraZeneca and served as Consultant/Advisory Board member for Genetic Analysis AS, and as a speaker for Biocodex, Ferring Pharmaceuticals, Takeda, AbbVie and MEDA. Magnus Simrén has received unrestricted research grants from Glycom and Danone Nutricia Research, and served as advisory board member/consultant and/or speaker for Biocodex Glycom, Danone Nutricia Research, Ironwood, Genetic Analysis AS, Kyowa Kirin, Menarini, Arena, Adnovate, Tillotts, Takeda, Alimentary Health, AlfaSigma, Falk Foundation and Shire. Figures were created with Biorender.com."

"FUNDING INFORMATION This study was funded in full by grants from the Swedish state under the agreement between the Swedish government and the county councils, the ALF‐agreement (ALFGBG‐726561, 722,331, 875,581), the Swedish Research Council (2018–02566 and 2021–00947), and the Faculty of Medicine at the University of Gothenburg (Dnr DS2019/1843)."

"Adult sex‐ and age‐matched IBS patients and HC were recruited by public advertisement in university buildings and university‐related social media of the University of Gothenburg, Sweden. The IBS diagnosis (Rome IV) was confirmed by experienced gastroenterologists (M.S. and H.T.) after initial assessment by a trained medical doctor (J.A.). The same data were collected for the whole study population. Exclusion criteria were specific allergy or intolerance to food, severe cardiovascular, hepatic, neurological or psychiatric diseases, other GI disease, diabetes, compliance to a specific diet (including gluten‐free, vegan, low‐carb high‐fat, and low fermentable oligo‐, di‐, monosaccharides and polyols [FODMAP] diet), GI surgery (except for appendectomy or cholecystectomy), use of antibiotics within 1 month before inclusion, and pregnant or lactating females. Participants that already identified gluten as a trigger of their GI symptoms were also excluded. Baseline laboratory tests, including faecal calprotectin, tissue transglutaminase immunoglobulin (Ig) A antibodies, haemoglobin, leucocytes, thrombocytes, C‐reactive protein, sodium, potassium, calcium, albumin, e‐glomerular filtration rate, creatinine, alkaline phosphatase, alanine transaminase, aspartate aminotransferase, thyroxine, thyroid stimulating hormone, haemoglobin A1c, fasting glucose, cholesterol (total), high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, and triglycerides were done to rule out any severe concomitant disease. In addition, the participants reported usage of IBS medication (e.g., anti‐diarrhoeal medication, laxatives and neuromodulators) and probiotics. All participants signed informed consent at the screening visit and before any study related procedures. The study was approved by the regional Ethical Review Board in Gothenburg (Dnr 627‐18) in August 2018, and was carried out at Sahlgrenska University Hospital, Gothenburg, Sweden between October 2018 and November 2019, according to the declaration of Helsinki. All authors had access to the study data and reviewed and approved the final manuscript. Clinicaltrials.gov: NCT03869359."