Dr. Lior Lobel

The Laboratory of Diet-Host-Microbe Interactions

Our lab studies diet–microbe–host interactions, with one persistent emphasis: what gut bacteria are doing, not just which taxa are present. We ask how dietary and host-derived metabolites change bacterial enzyme activity within hours, and how those changes affect host physiology and immunity.

Our distinctive research focus is the post-translational modification (PTM) of bacterial proteins. Lysine acetylation, S-nitrosylation, and persulfidation form a a dynamic layer of protein regulation that is well characterized in eukaryotic biology but remains largely unexplored in the gut microbiome in vivo. We investigate PTMs as a mechanism through which diet can directly influence bacterial metabolism, independently of changes in microbial abundance.

To investigate these processes, we combine quantitative metaproteomics, metagenomics, gnotobiotic and germ-free mouse models, targeted enzymology, computational tools developed in our laboratory, and human clinical cohorts.

Our current research projects examine the relationship between soluble dietary fiber, acetylation of glutamate dehydrogenase (GDH), and intestinal ammonia metabolism, including potential links to responses to immune checkpoint blockade in melanoma. We also investigate persulfidation in Fusobacterium nucleatum and its regulation of bacterial adhesins in colorectal cancer; intratumoral bacterial antigens as potential targets for cancer immunotherapy in microsatellite-stable (MSS) tumors; microbial protein activity in inflammatory bowel disease and chronic kidney disease using metaproteomics; and the urinary microbiome (urobiome) in prostate cancer.

Across all these research directions, the aim is the same: find the enzyme, then steer it.