How Gut Microbes Evolve to Escape the Intestines and Trigger Chronic Infection

July 13, 2022

The gut is home to a plethora of pathobionts. When housed within the gut, they typically don’t cause problems. But when they escape the intestines in what is known as “leaky gut syndrome,” they can trigger chronic inflammation that leads to the development of autoimmune diseases. A team of researchers hypothesized that pathobionts evolve to become more pathogenic and potentially leave the gut over time.

A study titled Within-host evolution of a gut pathobiont facilitates liver translocation published in Nature examined how a pathobiont species evolves in mice over the course of three months. At the end of the experiment, they found that the microbes separated into two populations: one reminiscent of the original microbes, and one that gained mutations that allowed them to live outside of the gut and persist in lymph nodes and the liver.

To limit the pathobionts’ evolution, the authors of the study believe a diverse microbiome, which is in part based on diet, can prevent the overgrowth of one species and the potential evolution of harmful characteristics from repeated rounds of growth.

Citation for report:

Yang, Y., Nguyen, M., Khetrapal, V., Sonnert, N. D., Martin, A. L., Chen, H., Kriegel, M. A., & Palm, N. W. (2022). Within-host evolution of a gut pathobiont facilitates liver translocation. Nature, 607(7919), 563–570. https://doi.org/10.1038/s41586-022-04949-x