Our data indicate that oral administration of BLS-mix to newly weaned F4ab/acR− pigs ameliorates enteritis in an F4+ ETEC/VTEC/EPEC model; however, induction of IL-10–producing Foxp3− Treg cells by BLS-mix administration cannot account for the protection of newly weaned F4ab/acR− pigs from F4+ ETEC/VTEC/EPEC infection, and that excessive generation of CD4+IL-10+ T cells following consumption of BLS-mix during episodes of intestinal inflammation that is caused by enteric pathogens might prohibit clearance of the pathogen. This evidence concerns the gene CD4 and enteritis.