Harnessing the endogenous Type I-C CRISPR-Cas system for genome editing in Bifidobacterium breve

The lack of effective genetic tools for Bifidobacterium breve is an obstacle to studying the molecular mechanisms of its health-promoting effects, hindering the development of next-generation probiotics. Here, we introduce a gene editing method based on the endogenous CRISPR-Cas system, which can achieve gene deletion, single-base substitution, gene insertion, and successive gene editing in B. breve . This study will facilitate discovery of functional genes and elucidation of molecular mechanisms of B. breve pertaining to health-associated benefits.