ABSTRACTNonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease. The present study explores the clinical efficacy of probiotics in the treatment of patients with NAFLD by conducting a systematic search of relevant databases. The RevMan 5.4 software was used to evaluate the effects of probiotics on liver function (i.e. alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma-glutamyl transferase [GGT], lipid metabolism, blood glucose, inflammatory factors [e.g. tumor necrosis factor-α, TNF-α] and body mass index [BMI]) in patients with NAFLD. A total of 18 high-quality studies were included in the final meta-analysis. The results of the meta-analysis showed that the use of probiotics in the adjuvant treatment of patients with NAFLD improved liver function and reduced ALT levels (mean difference [MD]: −0.07; 95% confidence interval [CI]: −12.95, −7.19), AST levels (MD: −11.90; 95% CI: −16.55, −7.25) and GGT levels (MD: −8.61; 95% CI: −14.74, −2.48); additionally, the treatment effect was more obvious when the treatment time exceeded 12 weeks. Probiotic therapy reduced patients’ triglyceride levels (MD: −9.71; 95% CI: −18.39, −1.03) and total cholesterol levels (MD: −22.31; 95% CI: −25.41, −19.21). Probiotic treatment improved patients’ levels of fasting blood (MD: −8.22; 95% CI: −12.25, −4.20), insulin (MD: −2.68; 95% CI: −4.94, −0.41) and insulin resistance (MD: −0.72; 95% CI: −1.21, −0.24). Probiotic adjuvant therapy for patients with NAFLD reduced their BMI by approximately 1.67 (95% CI: −2.93, −0.41) and TNF-α levels. The adjuvant treatment of NAFLD with probiotics has a positive clinical effect, which is influenced by treatment time.