Microbes – bacteria, viruses, and other tiny organisms – make up the majority of the human body, outnumbering human cells 10 to one. In recent decades, scientists have begun to explore the genetic make-up of these microbes, called microbiomes, to see how their genes impact human health, including immunity, nutrition, and development.

Grace Lee, a fourth-year medical student at the Virginia Tech Carilion School of Medicine (VTCSOM), first became interested in microbiomes while working at the National Institutes of Health (NIH) prior to medical school. “I was in immunology working on vaccine research. But I realized while I was there that the hot new topic was the microbiome. We were just now discovering how important all these microbiotic differences are in all types of health conditions,” Lee said.

With her curiosity piqued at NIH, Lee found herself drawn to Xin Luo’s laboratory for her long-term research project. Research is one of the core value domains at VTCSOM. Luo is associate professor of biomedical science and pathobiology at the Virginia-Maryland College of Veterinary Medicine. One of her lab’s endeavors is to look at the maternal microbiome and how it may impact offspring before and after birth.

Lee began to work closely with a doctoral student in the lab, Brianna Swartwout, who is in the Translational Biology, Medicine, and Health graduate program. “We had co-discovered a difference between two Limosilactobacillus reuteri strains in activating antibody production with cells cultured in a petri dish,” Swartwout said. “Grace was able to identify that the next step for the project was to investigate whether the same difference is observed when the bacteria strains are administered to mice.”

Lee tested this by giving the bacteria to maternal mice during their pregnancy and lactation periods, and also to their pups directly. “When we gave it to them directly, we saw that these bacteria did seem to cause an increased immune response in the neonatal pups,” Lee said.

While the finding can’t immediately be implemented in humans, the hope is that as more research is done, it could help inform treatment for infants who have certain deficiencies, particularly in their immune response.

“One of the key findings was that two different strains of the same bacteria could have profoundly different influences,” Swartwout said. “There are a lot of probiotic products on the market and people are really interested in how you can modulate your gut microbiome to improve your health. But it's really hard to pin down empirical data on their efficacy and I think part of that could be explained by these differences we're seeing in strains. You might be using a particular strain that's just not tied to what your body needs at that time.”

The project was a good fit for Lee, who loves basic science, but also appreciated that the project had a translational aspect to it that could one day impact human health. “It was a great way to tie my clinical interest with some of my basic science interest,” Lee said.

Swartwout added Lee was able to bring a new perspective to the lab, as a medical student who is focused on improving human health. “There are a lot of differences between mice and humans. Grace was able to identify those differences and how the research needed to be framed to translate it to humans.”

“Brianna and Grace were a great team and together they made interesting discoveries that have enhanced our understanding of how the immune system develops in the neonate,” Luo said.

In May, Lee will graduate from VTCSOM and pursue residency in obstetrics and gynecology. She hopes to continue doing research. “Something my experiences have taught me is that medicine is constantly evolving and noticing anything that could improve patient care can lead to some really interesting research,” Lee said.

Lee will give a presentation on her project at the VTCSOM’s annual Medical Student Research Symposium on Friday, March 26, from noon to 6 p.m. The eight students in the class who are selected to receive letters of distinction for their project, including Lee, will give oral presentations. The rest of the Class of 2021 will give poster presentations on their projects, as part of the school’s rigorous research value domain of its curriculum.

Guests are encouraged to attend the symposium, which will be shared virtually this year. Participants are asked to register to receive the Zoom information to attend.