Effect of Bifidobacterium lactis 420 on microbiota and immune function

A pilot feeding trial was performed for four weeks to study the influence of Bifidobacterium lactis 420 on healthy adult volunteers. B. lactis levels increased by more than 1,000-fold. Total bifidobacteria increased only in subjects who had low initial levels. B. lactis 420 appeared to have some influence on the metabolism of the intestinal microbiota and immune markers were only marginally influenced. Interestingly, trends for inverse correlations between faecal TNF-a and IgA concentrations and B. lactis were noted. Further investigation with more subjects is needed to confirm these influences on the microbial metabolic activity.