Microbial remodeling of bile acids: emerging engineering strategies for precision fermentation and functional food innovation.

Bile acids (BAs) are emerging as key signaling metabolites at the interface of diet, the gut microbiota, and host physiology. Microbial transformation generates structurally diverse BA species that regulate host metabolism and immunity via receptor-mediated signaling pathways. Recent advances in synthetic biology enable the modular reconstruction of BA metabolic pathways in tractable microbial hosts, moving the field toward programmable control of BA composition. Integrating engineered chassis with process optimization and emerging technologies such as computational design, biosensors, and encapsulation is accelerating the development of scalable and predictable BA-remodeling platforms. These advances contribute to an emerging paradigm of precision microbiome engineering with broad implications in pharmabiotics, functional foods, and personalized microbiome therapies.