Synbiotic modulates intestinal microbiota metabolic pathways and inhibits DMH-induced colon tumorigenesis through c-myc and PCNA suppression

[Display omitted] •Synbiotic reduces the expression of genes related to colorectal carcinogenesis.•Synbiotic modulates functional metabolic pathways of the intestinal microbiota.•Synbiotic VSL#3 and PBY reduces colonic inflammatory response in colon. The use of probiotic and synbiotic is a promising strategy to modulate the intestinal microbiota, and thereby modify the risk of diseases. In this study, the effect of probiotic VSL#3, isolated or associated with a yacon-based product (PBY), on the functional metabolic pathways of the microbiota, in a colorectal carcinogenesis model, was evaluated. For this, mice induced to carcinogenesis were fed with standard diet AIN-93 M (CON), diet AIN-93 M and VSL#3 (PRO) or diet AIN-93 M with yacon and VSL#3 (SYN). The SYN group showed a highly differentiated intestinal community based on the MetaCyc pathways. Of the 351 predicted functional pathways, 222 differed between groups. Most of them were enriched in the SYN group, namely: amino acid biosynthesis pathways, small molecule biosynthesis pathways (cofactors, prosthetic groups, electron carriers and vitamins) carbohydrate degradation pathways and fermentation pathways. In addition, the synbiotic was able to stimulate the anti-inflammatory immune response and reduce the gene expression of PCNA and c-myc. Thus, we conclude that the synbiotic impacted more significantly the metabolic functions of the microbiota compared to the isolated use of probiotic. We believe that the enrichment of these pathways can exert antiproliferative action, reducing colorectal carcinogenesis. The prediction of the functional activity of the microbiota is a promising tool for understanding the influence of the microbiome on tumor development.