Published online Jun 30, 2019. doi: 10.13105/wjma.v7.i6.323
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
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.
To perform a systematic review and meta-analysis on potential benefits of probiotics among individuals with fatty liver or obesity or hyperlipidemia.
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).
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.
Single probiotics, especially Lactobacillus, have a potentially beneficial effect on improving obesity and dyslipidemia. Evidence on the fatty liver is limited.
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.