Effect of the probiotic CMS1 on the immune response and the oral microbiome: a randomized, double-blind, placebo-controlled, parallel study.

The oral cavity connects the external environment and the respiratory and digestive systems, and the oral microbial ecosystem is complex and plays a crucial role in overall health and immune defense against external threats. Recently, the potential use of probiotics for disease prevention and treatment has gained attention. This study aimed to assess the effect of CMS1 ( CMS1) consumption on the oral microbiome and immune function in healthy individuals through a 12-week clinical trial. This randomized, double-blind, placebo-controlled, parallel trial enrolled 90 healthy subjects. The consumption of CMS1 significantly increased salivary immunoglobulin A ( = 0.046) and decreased tumor necrosis factor-α (TNF-α) levels ( = 0.008). Analysis of the oral microbiota revealed changes in beta diversity, increased abundance of Firmicutes and Actinobacteria, and decreased abundance of Bacteroidetes and Fusobacteria after 12 weeks of consuming CMS1. Significant increases in various strains, including Lactobacillales, Bacilli, Streptococcaceae, Streptococcus, and Firmicutes, were observed in the CMS1 group after 12 weeks of intake. Additionally, and exhibited a positive correlation with TNF-α. These findings demonstrate the positive effect of CMS1 on the oral environment and immune function.