the University of Hong Kong, where he engaged in a research program studying oral infections, in addition to his clinical work. It was there that the two paths crossed. “When I started working on microbiological ideas, a colleague said, ‘Why don’t you speak to Céline? She’s got the expertise for that,’” Dr. Neelakantan says. “And there’s been no looking back. We’ve co-supervised students, won grants, and even awards together.” Now based at the University of Alberta, Dr. Neelakantan’s lab focuses on developing antimicrobial therapeutics, especially for those with weakened immune systems, which make them highly susceptible to infections. “About 60% of our work is dedicated to therapeutics for immunocompromised patients, particularly fungal infections, which are a huge problem,” he says. “The remaining 40% is on dental infections, root canals and caries prevention, and that’s where our collaboration with Céline continues.” the main culprit behind tooth decay. “It was like meeting an old friend from my PhD,” she laughs. “Except now, that friend was helping fight the bad bacteria.” For Dr. Neelakantan, the implications were immense. “This amazing probiotic strain could kill most diseasecausing bacteria without affecting the healthy ones,” he explains. “It even inhibits fungi like Candida from forming biofilms, which is remarkable because fungi are often overlooked in dental decay.” “Caries happen when bad bacteria take over in the acidic environment they thrive in,” Dr. Lévesque says. “But if we can help the good bacteria grow, they’ll keep everything in check. It’s not about getting rid of bacteria entirely, it’s about harmony.” Their research focuses on shifting that balance through a synbiotic—a blend of probiotics (beneficial bacteria) and prebiotics (the nutrients they feed on). “Probiotics alone often fail because they don’t have the right food source,” Dr. Neelakantan explains. “The idea is to deliver them with a compatible prebiotic so they can survive and function even in harsh environments.” Dr. Lévesque adds, “Why not give these bacteria something to eat? We’re thinking about prevention, not just treatment—something children could take before caries even start.” A “Good” Bacterium and a Big Idea Dr. Lévesque’s doctoral work focused on Streptococcus salivarius, one of the first bacteria to colonize a baby’s mouth after birth. “It’s a friendly bacterium,” she explains. “A good one.” She moved to Toronto for her postdoctoral work, trading the “good” bacteria for “bad”: Streptococcus mutans, the primary culprit behind dental caries. “I wanted to understand how mutans sticks to enamel and forms biofilms,” she says. “It’s fascinating how something so small can cause so much damage.” Dr. Lévesque’s discovery began with plaque samples collected from children with and without cavities. “When I saw one colony and it looked familiar. It was Streptococcus salivarius,’” she says. “It had the same morphology, so I saved it just out of curiosity.” That curiosity paid off. The strain, found in a cavityfree child, turned out to inhibit Streptococcus mutans, Caries happen when bad bacteria take over in the acidic environment they thrive in. But if we can help the good bacteria grow, they’ll keep everything in check. Tooth with dental caries and close-up view of microbes that cause caries Streptococcus mutans. 28 | 2026 | Issue 2 Issues and People
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