Dual-component kefir (grain and beverage) supplementation confers protective effects against Salmonella infection through immune modulation and pathogen inhibition.

Abstract

Salmonella infections remain a major public health challenge, and innovative probiotic strategies are urgently needed. This study investigates the protective effects of a kefir grain and beverage mixture against Salmonella Typhimurium infection in rats. Thirty-six male Sprague-Dawley rats were allocated to three groups: (1) control (no kefir or Salmonella), (2) kefir + Salmonella (Sal) receiving daily kefir grain/beverage for four weeks, and (3) Salmonella-only (no kefir). On day 21, both kefir-treated and Salmonella groups were challenged with S. Typhimurium 14028. Results showed that kefir treatment markedly lowered Salmonella levels in the liver, spleen, feces, and cecal contents. Liver enzymes activity and inflammatory markers- Interleukin 10, serum amyloid A, and tumor necrosis factor α-were lower in the kefir treated group relative to the Salmonella group, indicating reduced hepatic injury and systemic inflammation. Kefir consumption also mitigated the infection-induced rise in white blood cell counts, implying an overall suppression of the inflammatory response. Collectively, the findings support the combined use of kefir grain and beverage-a dual-source of live microbes and fermentation metabolites-as a potent probiotic intervention, capable of reducing pathogen proliferation, limiting organ and inflammatory damage, and modulate host immune responses during Salmonella infection in this rat model. Unlike prior studies focusing on the kefir beverage alone, our work demonstrates the synergistic protective effect of grain + beverage against Salmonella infection.