Fermented Kefir–Fiber Synbiotic Shows Broad Anti-Inflammatory Protein Reductions in Healthy Adults

A University of Nottingham team reports that a six-week randomized trial of a fermented kefir–based synbiotic—combining live kefir with a diverse prebiotic fiber mix—led to broad reductions in circulating inflammation-related proteins and improved blood lipid profiles in healthy adults.

The study, published in Journal of Translational Medicine, compared data from two parallel randomized trials: one testing the kefir synbiotic against a no-intervention control, and another evaluating omega-3 fatty acids or inulin fiber in separate cohorts. Adjusted analyses showed the synbiotic produced the largest number and magnitude of significant protein decreases, including IL-6, IFN-γ, SIRT2, 4EBP1, and chemokines CCL23, CCL25, and CCL28, measured through a 96-protein inflammation panel.

Metabolically, the synbiotic group showed improvements in total, LDL, and non-HDL cholesterol, but no significant changes in glucose or insulin. Serum butyrate concentrations increased, correlating inversely with IL-6 levels, suggesting that microbial short-chain fatty acid production may contribute to anti-inflammatory effects.

The authors emphasize that microbiome composition was not directly measured and that causal links between microbial metabolites and proteomic changes remain speculative. Still, the findings indicate that combining fermented foods with prebiotic fibers can generate multi-pathway anti-inflammatory signatures detectable within six weeks—warranting further long-term and mechanistic studies.