Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 7, 2016; 22(29): 6673-6682
Published online Aug 7, 2016. doi: 10.3748/wjg.v22.i29.6673
Microbiota-based treatments in alcoholic liver disease
Hotaik Sung, Seung Woo Kim, Meegun Hong, Ki Tae Suk
Hotaik Sung, Department of Molecular and Cell Physiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, United States
Seung Woo Kim, Department of Biomedical Science, Hallym University College of Medicine, Chuncheon 200-704, South Korea
Meegun Hong, Ki Tae Suk, Department of Internal Medicine, Hallym University Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Chuncheon 200-704, South Korea
Author contributions: Sung H and Kim SW contributed equally to this work; Sung H performed the majority of writing and contributed to acquisition, analysis, and interpretation of the data; Kim SW and Hong M contributed to the acquisition of data, analysis and interpretation of the data, and drafted the manuscript; Suk KT designed and critically revised the article for important intellectual content and finally approved the version to be published.
Conflict-of-interest statement: There is no conflict of interest associated with any of the senior author or other coauthors contributed their efforts in this manuscript.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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:
Correspondence to: Ki Tae Suk, MD, PhD, Department of Internal Medicine, Hallym University Chuncheon Sacred Heart Hospital, Hallym University College of Medicine, Gyo-dong, Chuncheon 200-704, South Korea.
Telephone: +82-33-240-5826 Fax: +82-33-241-8064
Received: February 29, 2016
Peer-review started: March 2, 2016
First decision: April 14, 2016
Revised: May 21, 2016
Accepted: June 13, 2016
Article in press: June 13, 2016
Published online: August 7, 2016

Gut microbiota plays a key role in the pathogenesis of alcoholic liver disease (ALD). Consumption of alcohol leads to increased gut permeability, small intestinal bacterial overgrowth, and enteric dysbiosis. These factors contribute to the increased translocation of microbial products to the liver via the portal tract. Subsequently, bacterial endotoxins such as lipopolysaccharide, in association with the Toll-like receptor 4 signaling pathway, induce a gamut of damaging immune responses in the hepatic milieu. Because of the close association between deleterious inflammation and ALD-induced microbiota imbalance, therapeutic approaches that seek to reestablish gut homeostasis should be considered in the treatment of alcoholic patients. To this end, a number of preliminary studies on probiotics have confirmed their effectiveness in suppressing proinflammatory cytokines and improving liver function in the context of ALD. In addition, there have been few studies linking the administration of prebiotics and antibiotics with reduction of alcohol-induced liver damage. Because these preliminary results are promising, large-scale randomized studies are warranted to elucidate the impact of these microbiota-based treatments on the gut flora and associated immune responses, in addition to exploring questions about optimal delivery. Finally, fecal microbiota transplant has been shown to be an effective method of modulating gut microbiota and deserve further investigation as a potential therapeutic option for ALD.

Keywords: Alcoholic liver disease, Gut, Microbiota, Probiotics, Treatment

Core tip: Alcoholic liver disease (ALD) brings about imbalance in the gut microbiota which results in deleterious immune responses that affect the liver. However, there is little research on therapy that targets this aspect of ALD pathophysiology. This review summarizes ALD-induced changes in gut microbiota and its associated inflammatory effects, and explores the gamut of latest research on microbiota-based treatments for ALD, which include probiotics, prebiotics, antibiotics, and fecal microbiota transplant.