Probiotics may help improve liver enzyme levels, hepatic steatosis, and some metabolic parameters in patients with non-alcoholic fatty liver disease (NAFLD), but evidence varies by strain and study design.
What the research shows
Multiple high-quality randomized controlled trials and meta-analyses indicate that probiotics and synbiotics can reduce liver enzymes (ALT, AST, GGT), improve hepatic steatosis as assessed by imaging, and positively affect lipid and glucose metabolism in NAFLD patients. Synbiotic yogurt containing Bifidobacterium animalis showed significant improvements in liver steatosis and enzymes over 24 weeks. Meta-analyses of over 1000 patients confirm probiotics improve liver function, steatosis, blood lipids, and insulin resistance, especially with treatment durations of 12 weeks or longer. However, one RCT using a multi-strain probiotic (MCP BCMC strains) did not find significant clinical improvements in hepatic steatosis or fibrosis but suggested probiotics may stabilize intestinal mucosal immunity and barrier function. Another clinical trial protocol plans to evaluate Lactobacillus acidophilus and Bifidobacterium lactis strains but results are pending. Preclinical and mechanistic studies highlight the role of gut microbiota modulation, including strains like Akkermansia muciniphila, in NAFLD pathogenesis and potential treatment. Overall, probiotics appear promising as adjunctive therapy for NAFLD, but strain-specific effects, optimal formulations, and long-term benefits require further research.
Best studied probiotic strains
Bifidobacterium animalis
Evidence is from a high-quality RCT with a relatively large sample size; effects observed with synbiotic yogurt including prebiotic inulin.
Lactobacillus acidophilus and Bifidobacterium lactis
Evidence is currently moderate and based on planned study; no published results yet.
MCP BCMC multi-strain probiotics
Strain details are not fully specified; clinical benefits were not significant but some immunological effects noted.
Akkermansia muciniphila
Evidence is low and mostly preclinical; no direct clinical trials in NAFLD patients.
Who may benefit
Safety
Probiotics and synbiotics used in the reviewed studies were generally well tolerated with no significant adverse effects reported. However, safety data are limited and long-term effects require further study.
Limitations
Heterogeneity exists in probiotic strains, dosages, treatment durations, and study designs. Some studies have small sample sizes or lack strain specificity. Clinical improvements in liver fibrosis and inflammation are less consistently demonstrated. More large-scale, well-designed RCTs with defined probiotic strains and longer follow-up are needed to confirm efficacy and optimal protocols.
PubMed sources
| Study | Type | Year | PMID |
|---|---|---|---|
| The Effect of Probiotics (MCP BCMC Strains) on Hepatic Steatosis, Small Intestinal Mucosal Immune Function, and Intestinal Barrier in Patients with Non-Alcoholic Fatty Liver Disease. Nutrients |
Randomized Controlled Trial | 2021 | 34579068 |
| Daily Consumption of Synbiotic Yogurt Decreases Liver Steatosis in Patients with Nonalcoholic Fatty Liver Disease: A Randomized Controlled Clinical Trial. The Journal of nutrition |
Randomized Controlled Trial | 2018 | 29931231 |
| The effect of daily consumption of probiotic yogurt on liver enzymes, steatosis and fibrosis in patients with nonalcoholic fatty liver disease (NAFLD): study protocol for a randomized clinical trial. BMC gastroenterology |
Clinical Trial | 2022 | 35255811 |
| Efficacy of probiotics on nonalcoholic fatty liver disease: A meta-analysis. Medicine |
Meta-analysis | 2023 | 36705359 |
| Role of gut microbiota and Toll-like receptors in nonalcoholic fatty liver disease. World journal of gastroenterology |
Research Study | 2014 | 24966608 |
| Gut microbiome-targeted therapies in nonalcoholic fatty liver disease: a systematic review, meta-analysis, and meta-regression. The American journal of clinical nutrition |
Meta-analysis | 2019 | 31124558 |
| Effect of Probiotics Therapy on Nonalcoholic Fatty Liver Disease. Computational and mathematical methods in medicine |
Meta-analysis | 2022 | 35677177 |
| Effects of gut microbial therapy on lipid profile in individuals with non-alcoholic fatty liver disease: an umbrella meta-analysis study. Systematic reviews |
Systematic Review | 2023 | 37605283 |
| Nutraceutical Approach to Non-Alcoholic Fatty Liver Disease (NAFLD): The Available Clinical Evidence. Nutrients |
Systematic Review | 2018 | 30142943 |