{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T17:36:32Z","timestamp":1789061792913,"version":"build-2803163510"},"reference-count":29,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2020,5,14]],"date-time":"2020-05-14T00:00:00Z","timestamp":1589414400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"This work was supported by a grant from Daewoong Pharmaceutical (Seoul, Korea).","award":["M2019C096900002"],"award-info":[{"award-number":["M2019C096900002"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Functional dyspepsia (FD) is associated with small intestinal bacterial overgrowth (SIBO). Several animal studies have reported that ursodeoxycholic acid (UDCA) has antibacterial and anti-inflammatory effects in the intestine. We hypothesized that UDCA may be effective against dyspeptic symptoms and SIBO in patients with FD. We conducted this randomized controlled trial to investigate the effects of UDCA in FD patients with SIBO. Twenty-four patients diagnosed with FD and SIBO based on lactulose breath test (LBT) were randomly assigned to either a UDCA treatment group or an untreated group. The treatment group received 100 mg of UDCA three times per day for two months; the untreated group was monitored for two months without intervention. After two months in both groups, we reevaluated LBT and FD symptoms using the Nepean dyspepsia index-K. FD symptoms in the UDCA-treated group were significantly reduced after two months compared with baseline and FD symptom scores between the UDCA-treated and untreated groups showed statistically significant differences after two months. In addition, the total methane gas levels for 90 minutes in LBT were significantly decreased after two months compared with baseline in the UDCA-treated group. In this preliminary exploratory study, we found that two months of UDCA treatment resulted in FD symptom improvement and reduced methane values during 90 minutes on the LBT, suggesting that methane-producing SIBO were associated with symptoms of dyspepsia and that UDCA was helpful in these patients. These findings need to be validated via large-scale controlled and well-designed studies.<\/jats:p>","DOI":"10.3390\/nu12051410","type":"journal-article","created":{"date-parts":[[2020,5,14]],"date-time":"2020-05-14T10:27:19Z","timestamp":1589452039000},"page":"1410","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["The Effect of Ursodeoxycholic Acid on Small Intestinal Bacterial Overgrowth in Patients with Functional Dyspepsia: A Pilot Randomized Controlled Trial"],"prefix":"10.3390","volume":"12","author":[{"given":"Bom-Taeck","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Family Practice and Community Health, Ajou University School of Medicine, Suwon 16499, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kwang-Min","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Family Practice and Community Health, Ajou University School of Medicine, Suwon 16499, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1213-5004","authenticated-orcid":false,"given":"Kyu-Nam","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Family Practice and Community Health, Ajou University School of Medicine, Suwon 16499, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1262","DOI":"10.1053\/j.gastro.2016.02.032","article-title":"Functional Gastrointestinal Disorders: History, Pathophysiology, Clinical Features and Rome IV","volume":"150","author":"Drossman","year":"2016","journal-title":"Gastroenterology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3486","DOI":"10.3748\/wjg.v22.i12.3486","article-title":"Helicobacter pylori eradication therapy for functional dyspepsia: Systematic review and meta-analysis","volume":"22","author":"Du","year":"2016","journal-title":"World J. Gastroenterol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"526","DOI":"10.1053\/gast.2001.27180","article-title":"Symptoms associated with hypersensitivity to gastric distention in functional dyspepsia","volume":"121","author":"Tack","year":"2001","journal-title":"Gastroenterology"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"783","DOI":"10.1111\/j.1572-0241.2003.07389.x","article-title":"Symptoms associated with impaired gastric emptying of solids and liquids in functional dyspepsia","volume":"98","author":"Sarnelli","year":"2003","journal-title":"Am. J. Gastroenterol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1036","DOI":"10.1053\/gast.1996.v110.pm8612991","article-title":"Risk indicators of delayed gastric emptying of solids in patients with functional dyspepsia","volume":"110","author":"Stanghellini","year":"1996","journal-title":"Gastroenterology"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1136\/gutjnl-2019-318536","article-title":"Novel concepts in the pathophysiology and treatment of functional dyspepsia","volume":"69","author":"Wauters","year":"2020","journal-title":"Gut"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1590\/S0004-28032012000400009","article-title":"Evaluation of small intestine bacterial overgrowth in patients with functional dyspepsia through H2 breath test","volume":"49","author":"Costa","year":"2012","journal-title":"Arq. Gastroenterol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1159\/000494718","article-title":"High Prevalence of Pathological Hydrogen Breath Tests in Patients with Functional Dyspepsia","volume":"100","author":"Petzold","year":"2019","journal-title":"Digestion"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"767","DOI":"10.1111\/apt.13945","article-title":"Randomised clinical trial: Rifaximin versus placebo for the treatment of functional dyspepsia","volume":"45","author":"Tan","year":"2017","journal-title":"Aliment. Pharmacol. Ther."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1194\/jlr.R500013-JLR200","article-title":"Bile salt biotransformations by human intestinal bacteria","volume":"47","author":"Ridlon","year":"2006","journal-title":"J. Lipid Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"S21","DOI":"10.5604\/01.3001.0010.5672","article-title":"The Role of the Gut Microbiota in Bile Acid Metabolism","volume":"16","year":"2017","journal-title":"Ann. Hepatol."},{"key":"ref_12","first-page":"83","article-title":"Ursodeoxycholic Acid and Its Taurine- or Glycine-Conjugated Species Reduce Colitogenic Dysbiosis and Equally Suppress Experimental Colitis in Mice","volume":"17","author":"Hindryckx","year":"2017","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"469","DOI":"10.1111\/bph.14095","article-title":"Tauroursodeoxycholic acid inhibits intestinal inflammation and barrier disruption in mice with non-alcoholic fatty liver disease","volume":"175","author":"Wang","year":"2018","journal-title":"Br. J. Pharmacol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1002\/cam4.1965","article-title":"Effects of ursodeoxycholic acid on the gut microbiome and colorectal adenoma development","volume":"8","author":"Pearson","year":"2019","journal-title":"Cancer. Med."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"534","DOI":"10.1136\/gutjnl-2016-313332","article-title":"Gut microbial profile is altered in primary biliary cholangitis and partially restored after UDCA therapy","volume":"6","author":"Tang","year":"2018","journal-title":"Gut"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1007\/s00253-016-8006-6","article-title":"Interaction of gut microbiota with bile acid metabolism and its influence on disease states","volume":"101","author":"Staley","year":"2017","journal-title":"Appl. Microbiol. Biotechnol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1016\/S0899-3289(00)00039-0","article-title":"Ways of measuring drinking patterns and the difference they make: Experience with graduated frequencies","volume":"12","author":"Greenfield","year":"2000","journal-title":"J. Subst. Abus."},{"key":"ref_18","first-page":"48","article-title":"Validation of the Nepean Dyspepsia Index- Korean version","volume":"15","author":"Lee","year":"2003","journal-title":"Korean J. Neurogastroenterol. Motil."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1038\/ajg.2017.46","article-title":"Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus","volume":"112","author":"Rezaie","year":"2017","journal-title":"Am. J. Gastroenterol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1016\/j.mehy.2017.07.005","article-title":"Is small intestinal bacterial overgrowth involved in the pathogenesis of functional dyspepsia?","volume":"106","author":"Tziatzios","year":"2017","journal-title":"Med. Hypotheses"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1408","DOI":"10.1111\/nmo.12399","article-title":"Associations between IL-1RA polymorphisms and small intestinal bacterial overgrowth among patients with irritable bowel syndrome from India","volume":"26","author":"Srivastava","year":"2014","journal-title":"Neurogastroenterol. Motil."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e13304","DOI":"10.1111\/nmo.13304","article-title":"Micro-inflammation in functional dyspepsia: A systematic review and meta-analysis","volume":"30","author":"Du","year":"2018","journal-title":"Neurogastroenterol. Motil."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"G227","DOI":"10.1152\/ajpgi.00267.2012","article-title":"A novel mechanism for gut barrier dysfunction by dietary fat: Epithelial disruption by hydrophobic bile acids","volume":"304","author":"Stenman","year":"2013","journal-title":"Am. J. Physiol. Gastrointest. Liver Physiol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1300","DOI":"10.1248\/bpb.b16-00094","article-title":"Ursodeoxycholic Acid Ameliorated Diabetic Nephropathy by Attenuating Hyperglycemia-Mediated Oxidative Stress","volume":"39","author":"Cao","year":"2016","journal-title":"Biol. Pharm. Bull."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Chung, J., An, S.H., Kang, S.W., and Kwon, K. (2016). Ursodeoxycholic Acid (UDCA) Exerts Anti-Atherogenic Effects by Inhibiting RAGE Signaling in Diabetic Atherosclerosis. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0147839"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"339","DOI":"10.1016\/j.aller.2016.12.003","article-title":"Beneficial effects of ursodeoxycholic acid via inhibition of airway remodelling, apoptosis of airway epithelial cells, and Th2 immune response in murine model of chronic asthma","volume":"45","author":"Karaman","year":"2017","journal-title":"Allergol. Immunopathol. (Madr)"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"G1089","DOI":"10.1152\/ajpgi.00574.2004","article-title":"Methane, a gasproduced by entericbacteria, slowsintestinaltransit and augments smallintestinal contractile activity","volume":"290","author":"Pimentel","year":"2006","journal-title":"Am. J. Physiol. Gastrointest. Liver Physiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"185","DOI":"10.5056\/jnm.2011.17.2.185","article-title":"Slow transit constipation associated with excess methane production and its improvement following rifaximin therapy: A case report","volume":"17","author":"Ghoshal","year":"2011","journal-title":"J. Neurogastroenterol. Motil."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1159\/000336174","article-title":"Comparison of lactulose and glucose breath test for diagnosis of small intestinal bacterial overgrowth in patients with irritable bowel syndrome","volume":"85","author":"Rana","year":"2012","journal-title":"Digestion"}],"container-title":["Nutrients"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6643\/12\/5\/1410\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:28:41Z","timestamp":1760174921000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6643\/12\/5\/1410"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,5,14]]},"references-count":29,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2020,5]]}},"alternative-id":["nu12051410"],"URL":"https:\/\/doi.org\/10.3390\/nu12051410","relation":{},"ISSN":["2072-6643"],"issn-type":[{"value":"2072-6643","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,5,14]]}}}