NCCIH Research Blog

This past fall, Claire M. Fraser, Ph.D., gave the annual NIH Rolla E. Dyer Lecture, which honors one of NIH’s past directors by featuring an internationally renowned researcher who has contributed substantially to the medical and biological knowledge of infectious diseases.

Dr. Fraser is professor of medicine, microbiology, and immunology and director of the Institute for Genome Sciences at the University of Maryland School of Medicine. Her research interests focus on characterizing the structure and function of microbial communities and genomics in the human gastrointestinal environment, as part of the NIH-funded Human Microbiome Project. Dr. Fraser’s most recent grant support includes funding from the National Institute of Allergy and Infectious Diseases and the National Institute of Diabetes and Digestive and Kidney Diseases. She also is engaged with collaborators funded by the National Center for Complementary and Integrative Health (NCCIH), and was a speaker at the Center’s 10th Anniversary Research Symposium in 2009.

Dr. Fraser’s Dyer Lecture, “Functional Dynamics of the Gut Microbiome in Health and Disease,” is now available online. She discussed the evolution of studies in her lab from single microbes that can be grown in culture to examination of complex communities in a number of environments, particularly the human gastrointestinal tract. A major focus was the intriguing possibility that the gut microbiota may play an important role in response to vaccines and susceptibility to enteric pathogens.

On a related theme, Dr. Fraser expressed her heightened interest in examining the hypothesis that probiotics can modulate and restore resident microbial ecosystems. As a collaborator with Patricia Hibberd, M.D., Ph.D., an NCCIH grantee, she described the impact of a probiotic on the structure and functional dynamics (gene expression) of the gut microbiota in a study of healthy individuals aged 65 to 80 years receiving the Haemophilus influenzae vaccine. The probiotic Lactobacillus rhamnosus GG ATCC 53103 (LGG) was administered in this preliminary open-labeled and placebo-controlled clinical trial, and using novel “omics” technologies, the team examined potential changes over the course of probiotic consumption. The phased analysis is still in progress, and transcriptomic findings shown to date were particularly compelling. Dr. Fraser expressed her fascination with continuing to systematically study the effects of probiotic bacteria on microbial-host functional dynamics in the gut and to elucidate how these organisms confer outcomes on the host.

In her final remarks, Dr. Fraser stated that the ongoing exploration of the human microbiome promises to bring more attention to the link between gut and brain interactions. Her current research raises the possibility that scientists can develop novel biologic approaches from probiotics to enhance mental health. NCCIH has high program interest in this area, as we still need a lot more research into the mechanisms by which gut bacteria interact with the brain. We still have a long way to go to clarify the exact neurogenic, immunologic, and metabolic pathways in understanding the role of microbiota in gut-brain connections, and we look forward to additional groundbreaking discoveries.