Stressing Out Cancer: Chronic Stress Induces Dysbiosis and Enhances Colon Cancer Growth.

Psychologic stress significantly impacts colorectal cancer, and chronic stress is known to decrease treatment efficacy and survival rates in patients with colorectal cancer. Previous studies have linked psychologic stress to changes in the gut microbiota, and the role of the microbiota in colorectal cancer progression is well characterized. Despite this, the mechanistic link between chronic stress and colorectal cancer remains unclear. In this issue of Cancer Research, Cao and colleagues reveal that chronic stress exacerbates colorectal cancer progression by reducing the presence of Lactobacillus johnsonii (L. johnsonii) and its metabolite protocatechuic acid (PCA). The authors demonstrate an increase in β-catenin expression as the major mechanism by which chronic stress potentiates cancer stemness and pathogenesis. Administration of L. johnsonii or PCA to stressed mice decreased β-catenin activity and colorectal cancer progression. This study defines a precise mechanism underlying chronic stress and colorectal cancer progression, emphasizing the relevance of psychologic well-being in colorectal cancer outcome. In addition, the study demonstrates the potential efficacy of L. johnsonii or PCA supplementation as promising therapeutics for colorectal cancer treatment. See related article by Cao et al., p. 771.