Calcium Tungstate Microgel Enhances the Delivery and Colonization of Probiotics during Colitis via Intestinal Ecological Niche Occupancy.

The effective delivery and colonization of probiotics are recommended for therapeutic interventions during colitis, the efficacy of which is hampered by abnormally colonized Enterobacteriaceae at pathological sites. To improve the delivery and colonization of probiotics, a calcium tungstate microgel (CTM)-based oral probiotic delivery system is proposed herein. CTM can selectively disrupt the ecological niche occupied by abnormally expanded Enterobacteriaceae during colitis to facilitate probiotic colonization. In addition, the calcium-binding protein, calprotectin, which is highly expressed in colitis, efficiently extracts calcium from CTM and releases tungsten to inhibit Enterobacteriaceae by displacing molybdenum in the molybdenum enzyme, without affecting the delivered probiotics. Moreover, CTM demonstrated resistance to the harsh environment of the gastrointestinal (GI) tract and to intestinal adhesion. The synergistic reduction of Enterobacteriaceae by 45 times and the increase in probiotic colonization by 25 times, therefore, result in a remarkable treatment for colitis, including restoration of colonic length, effective downregulation of the inflammatory response, restoration of the damaged mucosal barrier, and restoration of gut microbiome homeostasis.

Bionic Regulators Break the Ecological Niche of Pathogenic Bacteria for Modulating Dysregulated Microbiome in Colitis.

Therapeutic approaches that reprogram the gut microbiome are promising strategies to alleviate and cure inflammatory bowel disease (IBD). However, abnormal expansion of Escherichia coli during inflammation can promote pathogenic bacteria occupying ecological niches to resist reprogramming of the microbiome. Herein, a bionic regulator (CaWO4 @YCW) is developed to efficiently and precisely regulate the gut microbiome by specifically suppressing the abnormal expansion of E. coli during colitis and boosting probiotic growth. Inspired by the binding of E. coli strains to the mannose-rich yeast cell wall (YCW), YCW is chosen as the bionic shell to encapsulate CaWO4 . It is demonstrated that the YCW shell endows CaWO4 with superior resistance to the harsh environment of the gastrointestinal tract and adheres to the abnormally expanded E. coli in colitis, specifically as a positioner. Notably, the high expression of calprotectin at the colitis site triggers the release of tungsten ions through calcium deprivation in CaWO4 , thus inhibiting E. coli growth by replacing molybdenum in the molybdopterin cofactor. Moreover, YCW functions as a prebiotic and promotes probiotic growth. Consequently, CaWO4 @YCW can efficiently and precisely reprogram the gut microbiome by eliminating pathogenic bacteria and providing prebiotics, resulting in an extraordinary therapeutic advantage for DSS-induced colitis.