Effects of combined OncoTherad immunotherapy and probiotic supplementation on modulating the chronic inflammatory process in colorectal carcinogenesis

• Defects in the integrity of the gut barrier and changes in the microbiota trigger inflammation. • Inflammation and tumorigenesis: bi-directional pathway. • Toll-like receptors are strongly related to intestinal homeostasis maintenance and immune system. • Attractive physiological and immunological mechanisms of the probiotics via Toll-like receptors. • OncoTherad exhibits immunoprotective activity by activating the innate immune system. This study evaluated the effects of combined OncoTherad immunotherapy and probiotic supplementation on colorectal carcinogenesis chemically induced with 1,2-dimethylhydrazine (DMH) in mice. The animals were randomly allocated in five groups: Control, DMH: did not receive any treatment; DMH + OncoTherad: received weekly I.P. (intraperitoneal) dose of OncoTherad; DMH + Probiotic: received daily administrations via gavage of the functional food ( Lactobacillus : acidophilus and paracasei , Bifidobacterium : lactis and bifidum ) and DMH + Probiotic + OncoTherad: received the same treatment than the previous groups. After ten weeks of treatment, the large intestine was collected for immunohistochemical analysis of TLR4, MyD88, NF-κB, IL-6, TLR2, TRIF, IRF-3, IFN-γ, Ki-67, KRAS, IL-10, and TGF-β. For the statistical analysis, the variance tests (ANOVA) and Kruskal-Wallis were used and significance set at p < 0.05. Probiotic supplementation associated with the OncoTherad were able to modulate weight loss, stimulate the canonical signaling pathway TLR2/TLR4 (MyD88-dependent), reduce the non-canonical signaling pathway (TRIF-dependent), attenuate the proliferative pathway mediated by Ki-67 and KRAS oncogene, and stimulate the production of IL-10 and TGF-β cytokines. Thus, the association of OncoTherad and probiotic supplementation has shown important immudomulatory effects and could be considered a potential new therapeutic approach for colorectal cancer after further investigations.