Poly-β-hydroxybutyrate alleviated diarrhea and colitis via Lactobacillus johnsonii biofilm-mediated maturation of sulfomucin.

Maintainance of sulfomucin is a key end point in the treatment of diarrhea and inflammatory bowel disease (IBD). However, the mechanisms underlying the microbial sense to sulfomucin are poorly understood, and to date, there are no therapies targeting the secretion and maturation of sulfomucin in IBD. Herein, we biosynthesized poly-β-hydroxybutyrate (PHB) and found that PHB could alleviate inflammation caused by diarrhea and colitis by enhancing the differentiation of sulfomucin. Microbiota transplantation and clearance together demonstrate that PHB promoting sulfomucin is mediated by Lactobacillus johnsonii (L. johnsonii). Further studies revealed that PHB provides a favorable niche for L. johnsonii biofilm formation to resist disturbance and support its growth. L. johnsonii-biofilm alleviates colitis by regulating fucose residues to promote goblet cell differentiation and subsequent sulfomucin maturation. Importantly, PHB alleviates colitis by enhancing sulfomucin secretion and maturation in a L. johnsonii-dependent manner. PHB represents a class of guardians, acting as a safe probiotic-biofilm delivery system that significantly promotes probiotic proliferation. Altogether, this study adds weight to the possible role of probiotics and functional materials in the treatment of intestinal inflammation. The application of PHB and biofilm self-coating L. johnsonii carries high translational potential and may be of clinical relevance.