Effect of probiotic yogurt on short-chain fatty acids, inflammation, and oxidative stress biomarkers: A systematic review and meta-analysis of randomized controlled trials

AbstractShort-chain fatty acid (SCFA) production by fermented foods is a promising health strategy regarding inflammation and oxidative stress regulation. However, there is uncertainty whether probiotic yogurt (PY) is truly superior to conventional yogurt (CY). This systematic review and meta-analysis aimed to evaluate current evidence on the effect of PY on SCFAs, oxidative stress, and inflammatory biomarkers. A systematic literature search was performed up to December 2025 on PubMed, Scopus, Embase, Web of Science, and LILACS. Only randomized controlled parallel trials and crossover studies were included. A random effects meta-analysis of standardized mean difference (SMD) and mean differences (MD) was performed. A total of 15,326 articles were selected. After full-text review, 33 trials were considered. Pooled analysis showed a statistically significant increase in fecal acetate levels (SMD 0.29; 95% confidence interval [CI]: 0.02; 0.57). No significant differences were found for propionate, butyrate, and total SCFAs when combining parallel and crossover studies. Subgroup analysis revealed significant differences between study designs in acetate and butyrate. No significant differences were found for C-reactive protein (MD −0.61 mg/L; 95% CI: −2.25; 1.03) and oxidative stress biomarkers. In contrast, interleukin-10 showed a significant increase (SMD 0.48; 95% CI: 0.15; 0.80). Current evidence comparing PY with CY is very limited. Preliminary findings suggest increments of clinically uncertain relevance in fecal acetate levels and interleukin-10. However, due to the very low certainty of the evidence, superiority over CY is uncertain. Further trials are needed to standardize follow-up time doses and to address possible effect modification by study design.Registration: