Recombinant live biotherapeutics against chronic metabolic diseases: Challenges and opportunities.

Chronic metabolic diseases (CMDs) such as obesity, type 2 Diabetes mellitus (T2DM), metabolic dysfunction-associated steatotic liver disease (MASLD), and cardiovascular diseases (CVDs) represent an escalating global health crisis. The etiology and pathophysiology of CMDs are linked to persistent metabolic, inflammatory, and gut microbiome dysfunctions. Recombinant Live Biotherapeutic Products (rLBPs) are engineered microbes designed to deliver targeted metabolic, anti-inflammatory, or hormonal effects in situ, offering a promising alternative to conventional therapies. The development of the rLBPs is expected to bring a paradigm shift in the clinical management of chronic diseases. This chapter provides an overview of rLBPs by highlighting seminal examples of rLBPs, which are in the early phase of development for CMDs. It also deliberates on existing scientific, technical and regulatory challenges along with potential opportunities associated with the development of rLBPs.