Butyric acid, a metabolic end product of anaerobic bacteria, inhibits B-lymphocyte function.

The effect on B-lymphocytes of butyric acid, a metabolic by-product formed by selected anaerobic bacteria of the subgingival plaque and present in mM amounts in the crevicular fluid of patients affected by adult periodontitis was investigated. A dose-dependent inhibition of both mitogenesis and Ig production in B-cells challenged with formalinized Staphylococcus aureus, strain Cowan I (SAC), was observed. A role of this molecule in the downregulation of the local immune response in periodontal patients is proposed.