Wandering Gut Bacteria Linked to Autoimmune Disease

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Bacteria from the small intestines of mice and humans can travel to other organs and generate an autoimmune response.

 

Gut bacteria have been linked to a number of autoimmune diseases characterized by the immune system attacking healthy tissues.

 

To try and understand the link, researchers from Yale University focused on Enterococcus gallinarum, a bacterium they discovered is able to spontaneously travel away from the gut to lymph nodes, the liver, and spleen.

 

Using mouse models, the researchers found that when outside the gut, E. gallinarum caused the production of auto-antibodies (which attack the host’s healthy tissue) and inflammation.

 

Next, they confirmed the same type of inflammation happened in cultured liver cells of healthy people, and that the bacterium is present in livers of patients with autoimmune disease.

 

This follow-up is important because it confirms what the researchers saw in mice is also true in humans.

 

Through further experiments, the scientists found that they could turn off the autoimmune response in mice with an E. gallinarum-targeting antibiotic or vaccine.

 

These findings are particularly relevant to systemic lupus and autoimmune liver disease and suggest that treatment with an antibiotic or specific vaccine could improve the lives of patients with autoimmune diseases.

 

Reference

S. Manfredo Vieira, M. Hiltensperger, V. Kumar, D. Zegarra-Ruiz, C. Dehner, N. Khan, F. R. C. Costa, E. Tiniakou, T. Greiling, W. Ruff, A. Barbieri, C. Kriegel, S. S. Mehta, J. R. Knight, D. Jain, A. L. Goodman, M. A. Kriegel. Translocation of a gut pathobiont drives autoimmunity in mice and humans. Science, 2018; 359 (6380): 1156 DOI: 10.1126/science.aar7201