Genetically-Programmed Hypervesiculation of Lactiplantibacillus Plantarum Increases Production of Bacterial Extracellular Vesicles with Therapeutic Efficacy in a Preclinical Inflammatory Bowel Disease Model.

Inflammatory bowel diseases (IBD) affect over 6 million people globally and current treatments achieve only 10-20% rates of durable disease remission. Bacterial extracellular vesicles (BEVs) from probiotic lactic acid bacteria (LAB) are a promising novel therapeutic with mechanisms holding potential to drive increased rates of durable disease remission, including immunomodulation and intestinal epithelial tissue repair. However, translation of these cell-secreted nanovesicles is limited by long standing biomanufacturing hurdles, especially low production yields due to low biogenesis rates from cells. Here, Lactiplantibacillus plantarum is identified as a candidate LAB producing BEVs effective in treating acute dextran sulfate sodium (DSS)-induced murine colitis with greater efficacy than BEVs from probiotic Escherichia coli Nissle 1917. Genetic engineering of L. plantarum to create a hypervesiculating strain via inducible expression of a peptidoglycan-modifying enzyme is shown to enable a 66-fold increase in BEV productivity. Finally, hypervesiculating L. plantarum BEVs are confirmed to be therapeutically effective in the acute DSS mouse model of colitis, with superior reduction of mucosal tissue damage compared to live L. plantarum cells. These findings demonstrate that BEVs from genetically engineered hypervesiculating strain of L. plantarum are a promising preclinical therapeutic candidate for IBD that overcomes historical biomanufacturing limitations of BEV therapeutics.