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:
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.
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
Research background

An imbalance of the microorganisms could lead to many human diseases including dyslipi-demia, fatty liver, and obesity. Probiotic supplementation has been considered an alternative treatment.

Research motivation

Variety of probiotics has been available as ‘healthy’ products to consumers for many health purposes. These over-the-counter probiotics usually comprised of multiple probiotic strains with some health claims. Given limited evidence on the isolated effect of each probiotic strain, a systematic approach to synthesize current scientific evidence is essential.

Research objectives

This study was aimed to identify clinical trials on the use of single probiotics alone or in combi-nation with prebiotics for improving fatty liver, obesity, and dyslipidemia.

Research methods

This systematic review and meta-analysis was conducted using a rigorous methodology and supported by the use of systematic review management software. Titles and abstracts of the primary studies listed in PubMed and Embase databases were screened by two assessors using standard sets of inclusion and exclusion criteria. Data from the included articles were extracted in order to synthesize the effect of single probiotics on specific outcome measures.

Research results

A total of 13 randomized controlled trials were included. Three probiotics were included: Lactobacillus (10 studies), Bifidobacterium (2 studies), and Pediococcus (1 study). Probiotics significantly reduced BMI, reduced total cholesterol, reduced low-density lipoprotein, and increased high-density lipoprotein, compared to placebo; high study heterogeneities were observed. Only Lactobacillus could decrease triglyceride level with low heterogeneity. No included studies reported fibrosis score, liver functions, or subcutaneous fat outcomes.

Research conclusions

This systematic review emphasizes the effects of single genus non-food-based probiotics on decreasing BMI, total cholesterol and low-density lipoprotein as well as increasing high-density lipoprotein levels.

Research perspectives

Evidence on single genus probiotics is still limited. Additional clinical trials are needed for each of the single probiotics before combining two or more probiotics could be investigated.