Meta-Analysis
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World J Gastroenterol. Oct 28, 2013; 19(40): 6911-6918
Published online Oct 28, 2013. doi: 10.3748/wjg.v19.i40.6911
Effects of probiotics on nonalcoholic fatty liver disease: A meta-analysis
Yan-Yan Ma, Lin Li, Chao-Hui Yu, Zhe Shen, Li-Hua Chen, You-Ming Li
Yan-Yan Ma, Lin Li, Chao-Hui Yu, Zhe Shen, Li-Hua Chen, You-Ming Li, Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
Author contributions: Li YM proposed the study; Ma YY, Lin L, Yu CH, Shen Z, Chen LH collected data; Ma YY, Lin L, Yu CH, Shen Z, Chen LH, Li YM analyzed and interpreted the data; Ma YY drafted the manuscript; Li YM revised the manuscript; all the authors contributed to the design and interpretation of the study, read and approved the final version to be published.
Supported by National Natural Science Foundation of China, No. 81300303; Zhejiang Provincial Laboratory Animal Science Technology Program of China, No. 2011C37088; Natural Science Foundation of Zhejiang Province, China, No. Y13H030004
Correspondence to: You-Ming Li, MD, Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou 310003, Zhejiang Province, China. zlym@zju.edu.cn
Telephone: +86-571-87236532 Fax: +86-571-87236532
Received: June 30, 2013
Revised: August 24, 2013
Accepted: September 3, 2013
Published online: October 28, 2013
Abstract

AIM: To investigate the relationship between the gut-liver axis and nonalcoholic fatty liver disease (NAFLD), we performed a meta-analysis to evaluate the effects of probiotic therapy in NAFLD.

METHODS: We searched PubMed, Medline, Embase, Web of Science, the Cochrane Library and Chinese Biomedicine Database for all relevant randomized controlled trials on probiotics in patients with NAFLD/nonalcoholic steatohepatitis (NASH). A statistical analysis was performed using RevMan 5.0 software.

RESULTS: Four randomized trials involving 134 NAFLD/NASH patients were included. The results showed that probiotic therapy significantly decreased alanine aminotransferase (ALT), aspartate transaminase (AST), total-cholesterol (T-chol), high density lipoprotein (HDL), tumor necrosis factor (TNF)-α and homeostasis model assessment of insulin resistance (HOMA-IR) [ALT: weighted mean difference (WMD) -23.71, 95%CI: -33.46--13.95, P < 0.00001; AST: WMD -19.77, 95%CI: -32.55--7.00, P = 0.002; T-chol: WMD -0.28, 95%CI: -0.55--0.01, P = 0.04; HDL: WMD -0.09, 95%CI: -0.16-0.01, P = 0.03; TNF-α: WMD -0.32, 95%CI: -0.48--0.17, P < 0.0001; HOMA-IR: WMD -0.46, 95%CI: -0.73--0.19, P = 0.0008]. However, the use of probiotics was not associated with changes in body mass index (BMI), glucose (GLU) and low density lipoprotein (LDL) (BMI: WMD 0.05, 95%CI: -0.18-0.29, P = 0.64; GLU: WMD 0.05, 95%CI: -0.25-0.35, P = 0.76; LDL: WMD -0.38, 95%CI: -0.78-0.02, P = 0.06).

CONCLUSION: Probiotic therapies can reduce liver aminotransferases, total-cholesterol, TNF-α and improve insulin resistance in NAFLD patients. Modulation of the gut microbiota represents a new treatment for NAFLD.

Keywords: Probiotics; Nonalcoholic fatty liver disease; Nonalcoholic steatohepatitis; Liver function; Insulin resistance; Meta-analysis

Core tip: For many decades, researchers have carried out studies on the treatment of nonalcoholic fatty liver disease (NAFLD). However, no firm conclusions have been made regarding the efficacy of various treatments for NAFLD. Here we conducted a meta-analysis of the pooled data from randomized controlled trials to assess the efficacy of probiotic therapies and showed that probiotic therapy significantly decreased alanine aminotransferase, aspartate transaminase, total-cholesterol, high density lipoprotein, tumor necrosis factor-α and homeostasis model assessment of insulin resistance. Thus, probiotics may help to improve liver function, fat metabolism and insulin resistance in NAFLD patients.