Probiotic supplementation has little effect on peripheral blood regulatory T cells

Upper respiratory tract infection (URTI) is considered the most prevalent infectious condition in the population. It has high economic and productivity costs and is the most common new condition responsible for general practitioner visits.1 Prevention of URTI is a key reason for the consumption of a range of over-the-counter food supplements, including probiotics. We have shown that daily supplementation for 150 days with either Bifidobacterium animalis subsp. lactis Bl-04 (Bl-04) or Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp.