Association of Anti‐Inflammatory Dietary Adherence With Biomarkers and Gut Microbiota Related to Colorectal Cancer Risk: A Retrospective Study

Colorectal cancer is one of the most common cancers and a primary cause of death. The increased incidence in low- and middle-income nations highlights the need for better prevention. Chronic inflammation, obesity, and gut microbial dysbiosis are major risk factors for CRC, making nutritional interventions attractive. This study aims to examine the association between adherence to an anti-inflammatory diet and anthropometric, biochemical, inflammatory, molecular, and gut microbiota parameters related to colorectal cancer risk. In this retrospective analysis, anti-inflammatory diet adherents (<i>n</i> = 515) and non-adherents (<i>n</i> = 435) were compared. Hematological, hepatic, inflammatory, tumor, genetic/molecular, and gut microbiota tests were performed, and chi-square tests were used for categorical outcomes. Multiple regression was used to examine the association between adherence to an anti-inflammatory diet and the development of colorectal cancer. Multiple logistic regression analysis indicated that anti-inflammatory diets were associated with improved clinical, biochemical, and microbiome outcomes in patients with CRC. Diet adherence was associated with a lower risk of obesity, central obesity, dyslipidemia, anemia, and leukocytosis after adjusting for age, sex, BMI, smoking, and caloric intake (<i>β</i> = -1.90, SE = 0.26, OR = 0.15, 95% CI: 0.09-0.25). Several inflammatory markers, including CRP, IL-6, CEA, and MMP-9, decreased markedly (<i>p</i> < 0.001). Molecular alterations associated with CRC, including p53 mutation, Ki-67 overexpression, microsatellite instability, APC mutation, and β-catenin nuclear expression, were significantly decreased (<i>p</i> < 0.001). <i>Bifidobacterium</i>, <i>Lactobacillus</i>, <i>Faecalibacterium prausnitzii</i>, and <i>Akkermansia muciniphila</i> were increased, and pathogenic species decreased in the gut (ORs 2.10-2.30; <i>Fusobacterium nucleatum</i>, <i>Clostridium difficile</i>, pathogenic <i>Escherichia coli</i>; ORs 0.16-0.18). Anti-inflammatory diets significantly improve metabolic, inflammatory, tumor-related, and microbiome profiles in patients with CRC. Adherence to an anti-inflammatory dietary pattern is significantly associated with improved metabolic, inflammatory, molecular, and gut microbiota profiles, all of which are linked to colorectal cancer risk. These findings support anti-inflammatory dietary strategies as cost-effective and non-invasive approaches for colorectal cancer prevention and adjunctive management.