Systematic Reviews
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Jul 27, 2023; 15(7): 925-938
Published online Jul 27, 2023. doi: 10.4254/wjh.v15.i7.925
Associations between irritable bowel syndrome and non-alcoholic fatty liver disease: A systematic review
Jareth Jun Jie Ng, Wai Mun Loo, Kewin Tien Ho Siah
Jareth Jun Jie Ng, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
Wai Mun Loo, AliveoMedical, Mount Alvernia and Mount Elizabeth Hospitals, Singapore 574623, Singapore
Kewin Tien Ho Siah, Division of Gastroenterology and Hepatology, National University Hospital, Singapore 119228, Singapore
Kewin Tien Ho Siah, Department of Medicine, National University Hospital, Singapore 119228, Singapore
Author contributions: Siah KTH contributed to the design and implementation of the research and supervision; Ng JJJ and Loo WM performed the analysis of the results and writing of the manuscript.
Conflict-of-interest statement: The authors declare that there is no conflict of interest.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised accordingly to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Kewin Tien Ho Siah, MD, Division of Gastroenterology and Hepatology, National University Hospital, NUHS Tower Block, Level 10, 1E Kent Ridge Road, Singapore 119228, Singapore. kewin_siah@nuhs.edu.sg
Received: March 26, 2023
Peer-review started: March 26, 2023
First decision: May 15, 2023
Revised: June 12, 2023
Accepted: July 3, 2023
Article in press: July 3, 2023
Published online: July 27, 2023
Processing time: 116 Days and 22.3 Hours
ARTICLE HIGHLIGHTS
Research background

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease with the rise of obesity and metabolic syndrome. Functional gastrointestinal disorders like irritable bowel syndrome (IBS) are increasing in prevalence.

Research motivation

At present, there is limited understanding regarding the links between the two conditions despite there being suggestions of possible overlap between IBS and NAFLD. We hope to explore literature to assess this overlap and also possible common pathophysiological links.

Research objectives

To review the current literature regarding the overlap of NAFLD and IBS and potentially identify common pathophysiological links which may show potential for utilizing common therapeutics to treat both conditions.

Research methods

A systematic search was done to assess current literature showing overlap between NAFLD and IBS in human subjects from PubMed, EMBASE and Cochrane.

Research results

We identified studies showing overlap between NAFLD and IBS. Both IBS and NAFLD patients demonstrated more metabolic risk factors like obesity, hypertension, dyslipidaemia and diabetes. IBS was seen to be more common in NAFLD patients and vice versa. Common pathophysiological links included the brain-gut-liver axis, intestinal permeability, gut microbiota dysbiosis, bile acid signalling dysregulation, obesity and metabolic syndrome.

Research conclusions

Our systematic review summarizes the current literature regarding IBS and NAFLD and demonstrates overlap between the two conditions. Common pathophysiological links were identified between both conditions.

Research perspectives

The evidence supports the association between IBS and NAFLD. With common postulated pathophysiology of both conditions discussed, further studies would be useful to further strengthen the association between both conditions and also look into possible common therapeutics.