NLRP6 as a candidate segmental barrier to carcinogenesis in the human gut: a hypothesis

Colorectal cancer (CRC) is a major global health burden, whereas small intestinal cancers are rare despite arising within the same gastrointestinal tract. This disparity suggests that segment-specific epithelial programmes may influence carcinogenesis. NLRP6 is an inflammasome-forming sensor with established roles in epithelial homeostasis, barrier maintenance, mucosal immune surveillance, and host-microbiota interactions. Public human tissue resources, an exploratory reanalysis of currently available single-cell data, and our local colonic cohort, provide hypothesis-generating observations compatible with segmental differences in NLRP6 expression, including very low bulk transcript abundance in human colonic samples. However, the currently available human evidence remains limited and heterogeneous, and does not yet support a simple binary model of presence in the small intestine and absence from the colon. Murine studies nevertheless support biological plausibility, as Nlrp6 deficiency exacerbates inflammation-driven colonic tumourigenesis and impairs epithelial repair. In addition, independent human studies indicate protein-level and clinicopathological relevance of NLRP6 in colonic disease, suggesting that its expression may vary according to segment, cell type, inflammatory context, and disease state. We therefore propose that NLRP6 may function as one candidate component of a segment-restricted epithelial defence and mucosal immune surveillance network in the human gut, potentially shaping CRC-relevant inflammatory and barrier conditions rather than acting as an established human tumour-suppressive mechanism. This model should now be tested through orthogonal human validation, including protein-based assays, spatial and single-cell analyses, and correlation with inflammatory status and clinical outcome, before any biomarker-guided intervention strategies are considered.