Ever wondered why some people get more cavities than others, even with the same brushing habits? A new study from Cornell University might have the answer. Researchers found that a specific gene linked to starch digestion can influence the bacteria in our mouths, possibly increasing the risk of cavities and gum disease for some.
A new study led by Dr Angela Poole at Cornel discovered that the AMY1 gene, which helps produce salivary amylase (the enzyme that starts breaking down starch in your mouth), affects how oral bacteria react to starchy foods. This could explain why some people deal with more dental problems than others, even with the same oral care routine. (Also read: How to achieve the perfect morning oral hygiene routine: Dentist recommends 10 essential steps )
How your genes influence starch digestion
Most people know to brush after eating sugar, but according to Dr. Angela Poole, some may need to be just as careful with starchy foods. The AMY1 gene, which varies from 2 to 20 copies per person, affects how well starch is broken down. More copies mean more salivary amylase, an adaptation from when humans transitioned to starch-rich agricultural diets.
The research team grew bacteria from saliva samples of 31 adults with different AMY1 copy numbers to see how their bacteria reacted to starch. They created dental plaque-like cultures with and without starch to observe the results. Dr. Poole explained, “We wanted to know how starch affects the mouth and if the response changes based on AMY1 copy number.” They discovered that bacteria from people with high AMY1 copy numbers responded differently to starch.
Specifically, two bacteria, Veillonella and Atopobium, were less abundant in samples from people with more AMY1 copies. These bacteria are linked to cavities and gum disease. Dr. Poole added, “People with more copies break down starch more efficiently, which influences the types of bacteria in their mouth.” It’s fascinating how both our bodies and the bacteria adapt over time.
The evolutionary angle makes this even more interesting. Scientists believe humans developed extra copies of the AMY1 gene around 10,000 years ago, after the agricultural revolution. More copies meant better starch digestion, helping our ancestors extract more calories during food shortages. Dr. Poole explained, “Populations with more access to starch tend to have higher AMY1 copies. It makes sense, being able to break down starch efficiently would have been a survival advantage in times of scarcity.”
How this could change dental care
The study also revealed that starch reduced bacterial diversity in biofilms. Additionally, people with periodontitis (advanced gum disease) had significantly lower bacterial diversity than those with healthy gums. In samples from individuals with high AMY1 copy numbers, researchers found more Streptococcus bacteria, which thrive on starch breakdown products. While some Streptococcus species cause cavities, others are beneficial and may help keep harmful bacteria in check.
Previous research by Dr. Poole found that people with high AMY1 copy numbers had higher levels of Porphyromonas endodontics, a bacteria strongly linked to gum disease. This new study sheds light on how salivary amylase interacts with starch to shape oral bacteria and potentially influence dental health.
In the future, these findings could lead to more personalized dental care. If your AMY1 copy number affects how your mouth responds to starch, dentists might tailor dietary and hygiene recommendations based on your genetics. Some people may need to be extra diligent about brushing after eating carbs to prevent dental issues.
This research is a great reminder that dental health isn’t one-size-fits-all. Your genes might be playing a role in how your mouth processes starchy foods, meaning some people should be extra careful after indulging in bread or pasta. So next time you enjoy a carb-loaded meal, just remember your AMY1 genes might be influencing more than you think.
Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.
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