Effects of ingestion of yogurts containing Bifidobacterium and Lactobacillus acidophilus on spleen and Peyer's patch lymphocyte populations in the mouse

Certain probiotic lactic acid bacteria have been reported to improve immune system function. Here, the effects of ingesting yogurts on lymphocyte popu lations in the spleens and Peyer's patches were determined in mice. Three p robiotic-supplemented yogurts containing Streptococcus thermophilus, Lactob acterillus bulgaricus, Bifidobacterium, and Lactobacillus acidophilus and o ne conventional yogurt containing only S thermophilus and L. bulgaricus wer e prepared from commercial starter cultures and used in the study. B6C3F1 f emale mice were fed the four different types of yogurts mixed with an AIN-9 3G diet in a 50:50 (wt/wt) ratio. Nonfat dry milk mixed at a 50:50 (wt/wt) ratio with AIN-93G diet was used as the control. After a 14-day feeding per iod. spleen and Peyer's patches were removed and lymphocytes subjected to p henotype analysis by flow cytometry. ingestion of the four yogurts had no e ffect on percentages of CD8(+) (cytotoxic T cells), B220(+) (B cells), IgA( +), or IgM(+) cells in spleen or Peyer's patches. The percentage of CD4(+) (T helper) cells was significantly increased in the spleens from one group of mice fed a yogurt containing Bifidobacterium and L. acidophilus, and a s imilar trend was found in the remaining two probiotic-supplemented yogurts. Effects on CD4(+) populations were not observed in spleens of mice fed con ventional yogurt or in the Peyer's patches of any of the four yogurt groups . Zn total, the results suggested that ingestion of conventional or probiot ic-supplemented yogurts for 2 weeks had very little effect on lymphocyte di stribution in the systemic or mucosal immune compartments.