Defined bacterial consortium

Class

Live biotherapeutic (multi-strain consortium)

A defined bacterial consortium is a live biotherapeutic product composed of a fixed set of characterized, non-pathogenic bacterial strains manufactured together in known proportions. Rather than acting on a single molecular receptor, the consortium works by recolonizing the gastrointestinal tract and restoring functions normally provided by a healthy gut microbiome. These functions include competitive exclusion of pathogens for nutrients and attachment sites, production of metabolites such as short-chain fatty acids that support the intestinal barrier, and modulation of local immune signaling. This approach is relevant in conditions where the normal microbial community has been disrupted or depleted, most notably after antibiotic treatment, in recurrent intestinal infections, and in some inflammatory or metabolic conditions linked to microbiome imbalance (dysbiosis). Using a defined, cultured set of strains rather than an unprocessed fecal-derived material allows manufacturers to control composition, dosing, and quality, and to attribute biological effects to specific organisms. The rationale for a multi-strain design, as opposed to a single organism, is that restoring a functioning ecosystem generally requires several complementary bacterial species working together, since a single strain rarely reproduces the metabolic diversity and ecological stability of a natural community.