José Fachi, Ph.D.

Research

In the Colonna lab, I will explore how metabolites produced by healthy gut bacteria promote intestinal immunity. Microbes that reside in the healthy human intestine play an important role in promoting metabolism and fortifying the immune system. One way they act is through the generation of short-chain fatty acids (SCFAs), which are produced when the bacteria digest dietary fibers. In the Colonna lab, I discovered that feeding mice acetate, one type of SCFA, protected them from infection with a bacterium that causes diarrhea—and that it does so by stimulating immune cells called ILC3s. Now, using cutting-edge techniques in cell and molecular genetics, immunology, and genomics, I will assess how acetate and other SCFAs activate mouse ILC3 cells—making them more responsive to immune-boosting compounds, enhancing their production of immune regulatory molecules, or altering their metabolism. I will also determine whether SCFAs such as acetate do the same to ILC3s cultured from human tonsils. This work could lead to the development of new strategies for treating intestinal infections, particularly in individuals for whom standard antimicrobial therapies are intense and/or ineffective.