Combination of Vitamin D and Probiotics Inhibits Chemically Induced Colorectal Carcinogenesis in Wistar Rats.

The modulation of inflammatory elements, cell differentiation and proliferation by vitamin D and the role of probiotics in the intestinal microbiota and immunogenic response have sparked interest in the application of both in chemotherapeutics and chemoprevention of colorectal tumors.Aims: The present study aimed to investigate the effects of isolated and/or combined treatment of vitamin D3 and probiotics on colorectal carcinogenesis.Main methods: Pre-neoplastic lesions were induced with 1,2-dimethylhydrazine in the colon of Wistar rats, which were treated with probiotics and/or vitamin D in three different approaches (simultaneous, pre-, and post-treatment). We investigated the frequency of aberrant crypt foci (ACF) and aberrant crypt (AC) in the distal colon, fecal microbiome composition, gene and protein expression through immunohistochemical and RT-PCR assays, and general toxicity through water consumption and weight gain monitoring.Key findings: Results confirm the systemic safety of treatments, and show a protective effect of vitamin D and probiotics in all approaches studied, as well as in combined treatments, with predominance of different bacterial phyla compared to controls. Treated groups show different levels of Nrf2, GST, COX2, iNOS, beta-catenin and PCNA expression.Significance: These experimental conditions explore the combination of vitamin D and probiotics supplementa-tion at low doses over pathways involved in distinct stages of colorectal carcinogenesis, with results supporting its application in prevention and long-term strategies.