Engineered PEA-producing Lactobacillus paracasei F19 prevents colitis-associated colorectal cancer in mice by modulating inflammatory–angiogenic signaling and beneficially reshapes gut microbiota composition

Abstract

Colitis-associated colorectal cancer (CAC) arises from the interplay between chronic inflammation, epithelial dysregulation, angiogenesis, and microbiota alterations. Palmitoylethanolamide (PEA) is an endogenous lipid mediator with anti-inflammatory and anti-angiogenic properties, but despite its promise, insufficient bioavailability at the intestinal mucosa represents a major hurdle. We investigated whether local, sustained PEA delivery via an engineered Lactobacillus paracasei expressing N-acyl-phosphatidylethanolamine-specific phospholipase D (pNAPE-LP) could prevent CAC by targeting inflammatory, angiogenic, and microbial pathways. pNAPE-LP/palmitate markedly reduced mucosal damage and tumor burden compared with the AOM/DSS group, while naïve pLP and palmitate alone were ineffective. Treatment suppressed epithelial proliferation and angiogenesis, restored p53-wt expression, and significantly increased colonic PEA levels, confirming effective in situ biosynthesis. Mechanistically, pNAPE-LP inhibited activation of the Akt/mTOR/p70S6K pathway and reduced HIF-1α expression. Microbiota profiling revealed profound tumor-associated dysbiosis characterized by the collapse of dominant commensalsand expansion of pathobionts in the AOM/DSS group. pNAPE-LP induced a robust ecological remodeling, shifting beta-diversity toward healthy controls, restoring key genera associated with mucosal homeostasis, and suppressing taxa overrepresented in the tumor state. These effects were strictly dependent on PEA release following substrate administration, enabled by NAPE-PLD expression. Engineered pNAPE-LP acts as a living biotherapeutic that locally delivers PEA while simultaneously reprogramming inflammation, angiogenesis, oncogenic signaling, and microbiota composition. This multimodal mechanism effectively interrupts the pathogenic feedback loops driving CAC. Engineered PEA-producing probiotics represent a promising strategy for mucosa-targeted prevention of inflammation-associated colorectal cancer.