Searching for a cure
First Canadian to win international award for women in STEM tackles inflammatory bowel disease, diversity
Dr. Carolina Tropini had never intended to study bacteria before she started her PhD, in fact, not studying bacteria was her only requirement.
Like most people, she saw bacteria as dirty, infectious agents that only carry pathogens. That all changed when she heard a Stanford professor passionately talk about gut microbes and their role in human health. A few projects in, she realized the misconception and started seeing the beauty microbes play, not only in our own health, but in the health of the planet as well.
“I realized the mistake that I made and I have never turned back once I started working on bacteria,” she says. “It’s such a deep and expansive world of things that we don’t know yet and they’re so important for human health and the health of the planet. It’s been an incredible chance to learn so much and work on things that are not only intellectually stimulating, but also very impactful.”
Tropini is this year’s winner of the Johnson & Johnson Women in STEM2D
Scholars Award in the field of engineering, one of six selected from more than 500 nominees worldwide. The award will provide her with three years of mentorship and $150,000 in funding. She is the first Canadian to win this award.
Her research looks at how the gut changes in inflammatory bowel disease (IBD). There is still no known cure for IBD. Her team has found that individuals who have IBD have microbiota that looks significantly different from someone without. They’re trying to find the specific bacteria that can ameliorate the inflammatory environment in the gut.
“The example I use is, if the IBD gut is like a desert and you’re trying to make it like a forest, the first thing you need to do is modify the environment so it can accept the forest,” she says. “In a desert, you’d have to water things and get rid of the sand. Specific species that are better adapted to the desert get introduced first and these make way for the more complex communities one would like to foster. We’d like to take a similar approach, but instead of plants, of course, we’re thinking about bacteria and microbial species and how we can introduce them and modify the environment so it’s more permissive for the good species we want to keep in there.”
Over the last two decades, researchers started realizing why we have so much bacteria in our bodies – we carry around somewhere in the neighbourhood of tens of trillions of organisms every day.
“We need them,” says Tropini. “They digest food that we’re not able to digest. They produce vitamins that we’re not able to produce, they protect us from pathogens and we’ve evolved with these communities and we really need them to be healthy. One of the things I find most beautiful is how much of human biology is tied to these organism, and we don’t even realize it.”
Tropini gives the example of childbirth. While it’s still debated, in general, there is no bacteria in the womb. As soon as the baby is born, the mother coats her vagina with bacteria that will help the baby consume milk, and during the process of birth, the baby is seeded with bacteria from the mother’s body at the vagina.
“The body of the baby gets inoculated with this bacteria, and these are the first bacteria and microbiota that the body sees” she says. “From that point on, the entire digestive tract of the baby gets set up to host these microorganisms. It’s really beautiful if you look at maternal milk, about a quarter of it is made up of things the baby cannot actually break down. There are sugars that only microbes are able to consume. It happens even for mothers who are malnourished, it highlights how important they are for our own functioning.”
Our modern lives have become optimized for fighting pathogens, but it’s also led to a loss in diversity in our microbiota. Between the heavy use of antibiotics, strong sanitization of our surroundings, and spending less time outdoors, we’re no longer exposed to as many bacteria as our ancestors.
“While this helps decrease the burden of infectious diseases, it’s correlated with a very large increase in inflammatory diseases,” says Tropini. “Our bodies are primed to be exposed to bacteria and viruses and microbes. Now all of a sudden, we’re not doing this anymore. There’s a mismatch between the bacteria that our body expects and the ones that we actually have.”
Our diet has also led to this loss of diversity. Our ancestors used to have high amounts of digestible fibre in their diets, but now that we eat more processed foods, we don’t see nearly as many bacteria.
Our microbiota can change overnight, but our biology has remained relatively identical to that of our ancestors from the last few centuries.
“We have a microbiota adapted for foods that are very highly processed and a lifestyle that is different than what our biology got set up with,” she says. “We think this mismatch basically is what is leading to a lot of the inflammatory diseases, which has an effect on diseases like allergies, obesity, diabetes. All of which our ancestors did not know existed.”
As a first-generation college graduate, Tropini knows firsthand the importance of reaching out to underrepresented communities, especially in allowing Indigenous, people of colour, and women to feel empowered and supported as academics. Her lab works with Indigenous communities to provide students with internships.