Jonathan P. Jacobs is a gastroenterologist and scientist studying the intestinal microbiome in patients with inflammatory bowel disease (IBD), obesity, and other disorders. He graduated magna cum laude with highest honors from Harvard University with a BA in biochemistry. He subsequently received his MD from Harvard Medical School, graduating magna cum laude in a special field. During college and medical school, he trained in an immunology laboratory studying rheumatoid arthritis with funding from the Howard Hughes Medical Institute. He completed a residency in internal medicine at Stanford University and then joined UCLA to pursue gastroenterology training in the Specialty Training and Advanced Research program. He was awarded a PhD in cellular and molecular pathology for his research on the IBD microbiome and afterward joined the UCLA Division of Digestive Diseases faculty. He established the UCLA Microbiome Core in 2016—which provides a comprehensive suite of microbiome-related services to support microbiome research by the UCLA scientific community—and is now co-director of the Goodman-Luskin Microbiome Center. Ongoing projects in his laboratory employ animal models and multi-omics analyses of patient cohorts to define the roles of microbes and their products in IBD, obesity, colon cancer, and other diseases.