lactis HN019 (HN019) on periodontal clinical parameters, including gingival bleeding, presence of plaque, gingival tissue immunocompetence, including expression of beta-defensin (BD)-3, toll-like receptor 4 (TLR4), differentiation cluster (CD)-57 and CD-4, and saliva immunological properties, including IgA levels. This evidence concerns the gene CD4 and Gingival bleeding.