Koumiss promotes Mycobacterium bovis infection by disturbing intestinal flora and inhibiting endoplasmic reticulum stress

Abstract

Mycobacterium bovis is the causative agent of bovine tuberculosis and also responsible for serious threat to public health. Koumiss is a fermented mare's milk product, used as traditional drink. Here, we explored the effect of koumiss on gut microbiota and the host immune response against M bovis infection. Therefore, mice were treated with koumiss and fresh mare milk for 14 days before M bovis infection and continue for 5 weeks after infection. The results showed a clear change in the intestinal flora of mice treated with koumiss, and the lungs of mice treated with koumiss showed severe edema, inflammatory infiltration, and pulmonary nodules in M bovis-infected mice. Notably, we found that the content of short-chain fatty acids was significantly lower in the koumiss-treated group compared with the control group. However, the expression of endoplasmic reticulum stress and apoptosis-related proteins in the lungs of koumiss-treated mice were significantly decreased. Collectively, these findings suggest that koumiss treatment disturb the intestinal flora of, which is associated with disease severity and the possible mechanism that induces lungs pathology. Our current findings can be exploited further to establish the “gut-lung” axis which might be a novel strategy for the control of tuberculosis.