Daily intake of household-produced milk kefir on Salmonella Typhimurium infection in C57BL/6 mice: mortality, microbiota modulation, and immunological implications.

This article investigates the effects of daily consumption of household-produced milk kefir, a probiotic-rich fermented beverage, on Salmonella enterica serovar Typhimurium infection in C57BL/6 mice. While kefir intake prior to infection reduced intestinal inflammation and altered cytokine profiles by decreasing IL-10 and increasing IFN-γ, it did not improve infection outcomes; instead, it was associated with higher fecal Salmonella counts and increased mortality. Metabarcoding analysis revealed kefir-induced changes in gut microbiota composition and increased butyric acid production before infection, but these alterations potentially facilitated systemic pathogen translocation and worsened disease severity. The findings suggest that kefir at the tested dosage may not be effective against acute Salmonella infections and highlight the need for cautious evaluation of probiotic-rich beverages during such infections due to possible adverse effects.