Feasibility of integrated dietary assessment, targeted fecal bacterial profiling and screening colonoscopy: the prospective ColoMAR-1 pilot study

Background ColoMAR-1 was a prospective pilot designed to test the operational feasibility of integrating dietary assessment, blood and stool collection, targeted fecal bacterial profiling, screening colonoscopy and normal-mucosa biopsies, while generating exploratory data on colorectal polyps and fish intake. Methods Thirty asymptomatic adults aged ≥ 40 years were enrolled in a single-center observational pilot. The prespecified primary endpoint was completion of all study variables in ≥ 80% of participants (≥ 24/30). Component-specific feasibility and colonoscopic findings were summarized. In participants with sufficiently complete dietary data, marine-food frequency was compared with polyp status using exact Fisher-Freeman-Halton tests with Benjamini-Hochberg false-discovery-rate correction. Results All 30 participants returned the dietary questionnaire and underwent blood sampling; targeted fecal bacterial profiling was processed in 27/30 (90.0%) and colonoscopy was completed in 29/30 (96.7%). Paired right- and left-colon biopsies were obtained in all 29 colonoscoped participants, with no study-related procedural complications. Only 16/30 questionnaires (53.3%) were sufficiently complete for item-level dietary analysis; therefore, the composite feasibility endpoint was not met. Polyps were detected in 9/29 participants (31.0%; 95% CI 17.3–49.2), with an adenomatous component in 6/29 and a hyperplastic component in 5/29; no colorectal cancers were identified. In the complete dietary subset (n = 16), oily-fish frequency showed a nominal association with polyp status (exact P = 0.010; FDR q = 0.079); a post hoc weekly-versus-lower comparison found 0/10 versus 4/6 participants with polyps (Fisher exact P = 0.008). White-fish frequency also showed a nominal association (P = 0.030; q = 0.119), but in the opposite direction. No marine-food association remained significant after multiplicity correction. Conclusions The colonoscopy and biospecimen pathway was highly feasible, but the exhaustive self-administered dietary questionnaire was the principal bottleneck and prevented achievement of the prespecified composite endpoint. The 31% polyp detection rate and exploratory dietary and bacterial-marker patterns support a larger validation study using a shorter, prospectively standardized dietary instrument. These exploratory findings do not establish protective or causal effects.