Metagenome of Tibetan kefir grains and its alleviating effect on dysfunction of gut microbiome and depressive colorectal cancer comorbidity induced by chronic stress and AOM/DSS

The prevalence of major depression in cancer patients ranges from 5% to 26%. The research on the screening of neurotrophic and anticancer psychoprobiotics is way of important. The aim of this work was to demonstrate the interventional effect of Tibetan kefir fermented goat milk on colorectal cancer and a co-morbidity model established by chronic unpredictable stress (CUMS). The results showed that the Tibetan kefir fermented milk significantly alleviated the manifestations of depressive behavior and altered the level of corticotropin-releasing factor (CRF), serum corticosterone, and inflammatory factors (IL-6, IL-17, TNF-α and IL-1β) in serum, hippocampus and colon Moreover, the Tibetan kefir fermented milk could alleviate the inflammatory response and the hyperactivity of the HPA axis and inhibite the disturbance of 5-hydroxytryptamine system caused by colorectal cancer and CUMS to prevent the progress of depressive colorectal cancer. These results interpreted the potential mechanism of Tibetan kefir on antidepressant and anticancer. It provided a theoretical basis for the exploitation of psychotropic probiotic dairy products and enriched patients' dietary supplement.