Immunological effects of Kefir produced from Kefir grains versus starter cultures when fed to mice

摘要

Background: Natural kefir grains have a unique microbiota. The structure contains lactic acid bacteria (LAB), acetic acid bacteria, and yeast in specific ratios, in a polysaccharide matrix. Authentic kefir is produced by a traditional method using kefir grains cultured in milk. In contrast, starter cultures are used instead of kefir grains in the industry. The commercial kefir starter cultures used are limited and often very different from the kefir grain microbiota. The resultant commercial “kefir” is just a fermented drink containing some probiotic microorganisms and does not possess the same microbial population or chemical and physical characteristics of authentic kefir. The aim of this project was to determine and compare the effects on the mouse immune system of kefir produced using natural kefir grain versus commercial kefir produced by starter culture.Methods: Kefir produced with different cultures was fed to Balb/c mice (6-8 weeks, 20-25 grams, male) by gavage for two weeks at 300 μl/day. Intestinal tissues were collected from sacrificed mice at the end of the trial. The control group of mice (CNI group) were fed with phosphate buffered saline (PBS). The experimental treatments were mice fed mice fed authentic kefir produced using kefir grains (KGI group) and mice fed kefir produced using starter culture (STI group). Immunoglobulin (Ig) A, Immunoglubulin G, Interleukin (IL)-4, Interleukin-10, Interleukin-12, Toll Like Receptor (TLR)-4 were analyzed immunologically in intestinal fluid samples. Results: Results indicated that IgA values were 60.87, 72.78 and 55.31 ng/mL; IgG values were 26.59, 38.90 and 29.44 ng/mL; IL-4 values were 84, 40.28 and 53.28 pg/mL; IL-10 values were 110.98, 175.91 and 134.77 pg/mL; IL-12 values were 53.90, 22.93 and 24.75 pg/mL; TLR-4 values were 0.53, 0.43 and 1.37 ng/mL, for the CNI, KGI and STI groups, respectively.Conclusion: The high probiotic content of grain kefir had the ability to modulate many immunological mechanisms.