A new study suggests that chronic stress can accelerate colorectal cancer progression by disrupting gut microbiota, especially lowering levels of Lactobacillus, a beneficial bacterium essential for immune response.

Researchers tested this by inducing chronic stress in mice through daily restraint, mimicking human stress.

Stressed mice showed faster tumor growth and reduced beneficial bacteria, compromising their cancer-fighting ability. Both stressed and non-stressed mice developed tumors 11 weeks after antibiotic treatment depleted their gut bacteria.