Garrett investigates host-microbiota interactions in health and disease. She is interested in the interplay between the gastrointestinal immune system and the gut
microbiome, particularly in the context of
inflammatory bowel disease and
colorectal cancer. She has shown that the gut microbiota influence both innate and adaptive immune populations, contributing to immune homeostasis and disease. She identified specific microbial species, pathways, and metabolites that impact health and disease states. Garrett has investigated the microbes and immune cells that play a role in carcinogenesis and intestinal homeostasis. She has developed approaches that combine meta-
omics, microbiology, cellular immunology, biochemistry, cell biology, and cancer biology. To uncover fundamental biological mechanisms and apply findings to precision medicine, Garrett combines mouse models, human specimens, and mammalian and bacterial cells, as well as
in vivo and
in vitro model systems. Garrett has shown that
Fusobacterium nucleatum, a microbe of the mouth, is abundant in colon tumors. She believes that this could be an early indicator of carcinogenesis. The biobank is the most comprehensive collection of specimens in the world, using samples of people from the
Nurses' Health Study and other long-term cohort studies. In 2020 she was elected to the
American Society for Clinical Investigation, who awarded her the Marian W. Ropes, MD Award in 2023. In 2025, she was elected to the American Academy of Arts and Sciences and the National Academy of Medicine. == Selected publications ==