Effects of fermented dairy products on inflammatory biomarkers: A meta-analysis

Aim: Fermented dairy products (FDPs) are made from raw milk under the action of specific microorganisms by lactic acid bacteria fermentation or co-fermentation of lactic acid bacteria, bifidobacteria, and yeast. The aim of this study was to explore the effects of FDPs on inflammatory biomarkers. Data synthesis: A comprehensive search was conducted on four electronic databases, including PubMed, Web of Science, Embase, and the Cochrane Library. Finally, fourteen trials (15 arms) were included in this meta-analysis: yogurt ( n = 9), fermented milk ( n = 4), and kefir (n = 2). Additionally, the random effects model or fixed-effects model was used to pool the study results. Firstly, the analysis indicated that FDPs' supplementation decreased the levels of C-reactive protein (CRP) (SMD = -0.21; 95% CI: -0.40, -0.02; P Z 0.033) and increased interferongamma (IFN-gamma) levels (SMD = 0.12; 95% CI: 0.01, 0.23; P = 0.033). Furthermore, we obtained some statistically significant results in the following subgroups: CRP decreased in participants with metabolic diseases. IFN-gamma increased in the intervention that lasted >= 12 weeks, Asian, yogurt, and healthy population. Finally, there was no significant effect on tumor necrosis factor-alpha, interleukin (IL)-6, IL-10, and IL-2. Conclusions: FDPs reduced CRP and increased IFN-gamma, but they had no effect on other inflammatory markers. The results showed that the consumption of FDPs was slightly associated with reduced inflammation, but because of the limited literature, these results should be interpreted with caution. (c) 2023 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

Automated summary

The aim of this study was to explore the effects of fermented dairy products (FDPs) on inflammatory biomarkers. The analysis showed that FDPs supplementation decreased CRP levels and increased IFN-gamma levels, but had no effect on other inflammatory markers. These findings should be interpreted with caution due to limited literature.