Probiotic G.I. provides 10 billion CFU per capsule of the beneficial bacteria Lactobacillus acidophilus, Lactobacillus salivarius, Lactobacillus casei, Bifidobacterium bifidum, Bifidobacterium lactis and Streptococcus thermophilus. Research indicates that these strains provide particular support for healthy immune balance within the G.I. tract. Beneficial microflora are crucial for proper gut associated lymphoid tissue (GALT) function and development. The GALT helps protect intestinal mucosa from allergens and toxins and is a major component of the body's immune system. It is estimated that more than 70% of the body's B lymphocytes are found in the GALT. Probiotics are believed to support healthy GALT composition, and in turn, support barrier function, G.I. epithelial cell health and T cell function within the G.I. tract. Some probiotic strains may also modulate local production of cytokines in the G.I. epithelium. B. lactis supports healthy T cell activity and cytokine production in the intestine, at least in part by regulating transcription of genes that encode for cytokines. L. acidophilus promotes healthy cytokine production in the colon. Research also suggests that metabolites produced from Streptococcus thermophilus may cross the intestinal barrier to support healthy cytokine production and immune function.