Meta-Analysis
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Meta-Anal. Jun 30, 2019; 7(6): 323-338
Published online Jun 30, 2019. doi: 10.13105/wjma.v7.i6.323
Single strain probiotics for dyslipidemia, fatty liver, and obesity: A systematic review and meta-analysis
Krit Pongpirul, Kantima Janchot, Yudi Dai
Krit Pongpirul, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
Krit Pongpirul, Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, United States
Kantima Janchot, Panacee Group Co., Ltd, Bangkok 10110, Thailand
Yudi Dai, Harvard T.H. Chan School of Public Health, Boston, MA 02115, United States
Author contributions: Pongpirul K contributed to conception and design of the study; Pongpirul K, Janchot K and Dai Y contributed to acquisition of data, analysis and interpretation of data, drafting the article, final approval.
Supported by The Thailand Research Fund and Panacee Group Co., Ltd, No. RDG6150124; and Ratchadapiseksompotch Fund (Matching fund), Faculty of Medicine, Chulalongkorn University, No. RA-MF-12/62.
Conflict-of-interest statement: The authors deny any conflict of interest.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
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: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Krit Pongpirul, MD, MPH, PhD, Assistant Professor, Department of Preventive and Social Medicine, Faculty of Medicine, Chulalongkorn University, 1873 Rama IV Rd., Pathumwan, Bangkok 10330, Thailand. doctorkrit@gmail.com
Telephone: +66-866055088 Fax: +66-24111789
Received: April 6, 2019
Peer-review started: April 8, 2019
First decision: June 4, 2019
Revised: June 11, 2019
Accepted: June 18, 2019
Article in press: June 18, 2019
Published online: June 30, 2019
Abstract
BACKGROUND

A number of non-systematic reviews on the effects or mechanisms of probiotics on improving dyslipidemia, fatty liver, and obesity have been available but inconclusive to determine the independent effects of probiotics on each of the three conditions.

AIM

To perform a systematic review and meta-analysis on potential benefits of probiotics among individuals with fatty liver or obesity or hyperlipidemia.

METHODS

A systematic literature search was performed using PubMed and Embase. Adult participants of any gender without major comorbidities who received probiotics were considered following these criteria: (1) Studies on a single genus of probiotics with or without prebiotics; (2) Studies specifying the probiotic dosage into colony-forming units (CFUs); and (3) Studies on food-based probiotics were excluded. The primary outcome measures for fatty liver, obesity, and dyslipidemia were fibrosis score (kPa), body mass index (BMI; kg/m2), and serum lipid profiles (mg/dL), respectively. The secondary outcome measures for fatty liver and obesity were liver enzymes (U/L) and subcutaneous fat area (cm2).

RESULTS

A total of 13 articles, published between 1997 and 2018, fulfilled the selection criteria. Three probiotics were included, of which Lactobacillus was the most commonly studied (10 studies), followed by Bifidobacterium (two studies) and Pediococcus (one study). Probiotics significantly reduced BMI (P = 0.013), total cholesterol (P = 0.011), and low-density lipoprotein (P = 0.006) while increased high-density lipoprotein (P = 0.028); high heterogeneities were observed. Only Lactobacillus could decrease triglyceride level (P = 0.005) with low heterogeneity. No included studies reported fibrosis score, liver functions, subcutaneous fat outcomes.

CONCLUSION

Single probiotics, especially Lactobacillus, have a potentially beneficial effect on improving obesity and dyslipidemia. Evidence on the fatty liver is limited.

Keywords: Fatty liver, Obesity, Hyperlipidemia, Dyslipidemia, Probiotics, Non-alcoholic fatty liver disease, Overweight

Core tip: No consensus is available about the benefit of single probiotics on improving dyslipidemia, fatty liver, and obesity. This meta-analysis investigated the effect of single, non-food-based probiotics, with specified dosage and duration, on body mass index, serum lipid profiles, fibrosis score, liver functions, and subcutaneous fat.