When Laurie was in fourth grade, her teacher assigned the class an “ology project.” They had to take something they were interested in, make it an “ology,” and present it to the class. They could turn anything into an “ology,” leading one student to present on bubbleology. Laurie knew immediately what she wanted to do: “There was no hesitation, no ambiguity in my mind when I had to pick an ology project.” She chose microbiology.
Laurie immediately set to work, going around her school taking culture swabs from the bathrooms, water fountains, and door handles. She grew them on agar-filled petri dishes and presented them to the class. Though Laurie doesn’t remember the first time someone told her there were little organisms that exist beyond the resolution of the world we can see, she wishes she did. By fourth grade she wasn’t only interested in the bacteria themselves, but also the relationship between humans and bacteria. This curiosity has taken Laurie from her fourth grade ology project to her honors thesis.
Laurie is now a senior majoring in human biology. Since her sophomore year she has worked in the Relman lab in the microbiology and immunology department, where she has studied the human microbiome: all of the microorganisms that live in and on the human body. “Because there are so many of them,” she explained, “they play really important roles in our health, from making vitamins and minerals that we can’t synthesize ourselves, to educating our immune system and helping us fight off pathogens.”
Laurie’s work focuses on understanding how our microbiomes change over time. She’s been investigating the stability of the gut bacterial community and its resilience when challenged with a perturbation. Anytime we take antibiotics to wipe out an infection, we also challenge the “good” bacteria. In Laurie’s current research, she’s recruited participants to go through a more mechanical perturbation of their microbiome called a colonic lavage. This involves drinking four liters of fluid to mechanically wash out the gastrointestinal tract.
Surprisingly, Laurie says it doesn’t take a lot of pitching to get participants to sign up for the study. Since she’s analyzing bacterial genomic data, not human genomic data, she gets to share her data with the study subjects, and they get to learn more about a huge component of their bodies and their health. Laurie collects microbiota samples from the participants for ten weeks before and after the colonic lavage. Using these samples, she can see what species are present by analyzing the taxonomic composition, what their functional potential is through metagenomic analysis, and what functions they’re actually performing through metabolomics. All of these analyses are helping Laurie figure out what features of the community might predict resilience in the face of a disturbance.
Though it might seem like analyzing all of the samples involves a lot of delayed gratification, for Laurie, that isn’t always the case. While concentrating microbial DNA from samples for her analyses, there’s sometimes enough DNA to form a tiny white pellet at the bottom of the tube. One time Laurie’s samples were too small to see and she thought she had lost her entire data set. But at the end of the protocol, when she resuspended the DNA and took a sample, it was there. Her reaction? “Science works. It’s incredible.”
The ultimate gratification comes from being able to apply a full understanding of microbiome disturbances to future studies and clinical applications. Whether she’s swabbing water fountains or concentrating microbiota DNA, Laurie’s motivation comes from both the end goal and the process: “Even the small steps I can get a lot of enjoyment out of because I delight so much in the scientific process, which I think also harkens back to my scientific upbringing.”
by Kate Nelson