Bacillus subtilis: a shocking message from a probiotic

Abstract

How probiotics such as Bacillus subtilis exert a protective effect has been much debated. In this issue of Cell Host & Microbe, Fujiya et al. reveal that a B. subtilis quorum-sensing signal molecule, the competence- and sporulation-stimulating factor (CSF), is internalized via the mammalian oligopeptide transporter OCTN2, where it induces the heat shock protein Hsp27, which protects intestinal cells against oxidant-mediated tissue damage and loss of barrier function.