Designing for the Real World The research team—spanning microbiologists, pediatric dentists, and an orthodontist—is tackling the challenge of delivering these beneficial bacteria safely and effectively. “We don’t want to give pills,” says Dr. Lévesque. “We want to use foods children already enjoy, like milk or yogurt. Our strain comes from a healthy child’s mouth, so it’s safe and non-pathogenic. We confirmed it doesn’t carry any toxins or antibiotic resistance genes.” Dr. Neelakantan sees dairy as a natural vehicle. “Yogurt is nutrient-rich and already familiar to consumers,” he says. “But the principle is broader—the key is pairing the right probiotic with its preferred nutrient.” In early studies, the team observed that their probiotic strain could suppress biofilm formation across multiple species of decay-causing microbes. “Most therapies work on one or two bacteria,” says Dr. Neelakantan. “We were pleasantly surprised that this probiotic worked even against a polymicrobial community.” Equally notable is its ability to stick around. “One of the greatest difficulties for keeping therapeutic bacteria in the mouth is saliva, it washes everything away,” he says. “Most probiotics stay for only seconds before being swallowed. But this strain can stick to oral tissues, giving it a sustained effect. That’s very rare.” Dr. Lévesque’s team has also shown that the bacteria can push S. mutans off tooth-like surfaces in lab tests. “If mutans can’t attach to your teeth, it can’t cause caries,” she explains. “It’s as simple as that.” Not everything about Dr. Lévesque’s discovery has been predictable. “This strain has a mind of its own,” she says. “I tried to manipulate its genes, but it refuses to cooperate. It’s incredibly protective, it even has a kind of built-in security system on its DNA. It won’t let me remove or add anything!” To many scientists, that would be frustrating. To Dr. Lévesque, it’s fascinating. “It’s like the bacteria are manipulating us instead of the other way around,” she says. “They know how to protect themselves, and that’s exactly what makes this strain so stable. For probiotics, that’s a huge advantage, you want something that won’t mutate over time.” Lab Bench to Clinical Trials Early mouse models have already shown reduced tooth demineralization when the probiotic is introduced. “Basically, the good bacteria helped protect the teeth,” says Dr. Lévesque. With support from the Canadian Institutes of Health Research, the next step is clinical trials. Dr. Neelakantan believes this ecological strategy could be transformative. “Dental decay is the most common disease in the world, and we still don’t have an effective way to prevent it” he says. “If we can selectively inhibit disease-causing bacteria while preserving the health-associated ones, that’s a true paradigm shift. This will particularly benefit underserved communities and those lacking access to regular dental care.” The collaboration has also opened new lines of inquiry. Dr. Lévesque is now exploring whether the oral microbiome might communicate with the brain, similar to the well-known gut-brain axis. “If we can find connections or diagnostic markers, it could open up a whole new field,” she says. For both scientists, joy remains at the heart of the work. “When we were screening all those samples, it was time-consuming, but we have such fun,” says Dr. Lévesque. “That’s what keeps me going. Science should be joyful.” Dr. Neelakantan echoes the sentiment. “Our collaboration works because we’re both endlessly curious,” he says. “We’re not trying to conquer bacteria, we’re learning how to live with them, but without giving them the competitive advantage to be detrimental to our body.” One of the greatest difficulties for keeping therapeutic bacteria in the mouth is saliva. Most probiotics stay for only seconds before being swallowed. Dr. Prasanna Neelakantan and Dr. Lévesque are collaborators in oral microbiome and antimicrobial therapeutics research. 29 Issue 2 | 2026 | Issues and People
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