Probiotics

A New Tool for Oral Health

For a variety of reasons, people with diabetes are more susceptible to periodontal (gum) disease than the general public. Periodontal disease can affect both the soft tissues and the bone surrounding the teeth. While keeping blood glucose under control can help limit the risk of dental and oral problems, as can regular brushing and flossing, many people with diabetes would benefit from taking some extra steps to maintain a healthy mouth.

This is where oral probiotics may help. Most of the buzz about probiotics in recent years has been about their potential to aid in digestive health. But there’s another type of probiotics, called oral probiotics, that help manage the health of the mouth. This article takes a look at what oral probiotics are, how they work, and what their benefits might be.

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What’s in your mouth, and why

Your mouth was more or less sterile when you were born. The first time someone kissed your tiny lips, he passed his germs on to you. If this person had a lot of cavities or fillings, he probably gave you some harmful, cavity-causing forms of bacteria. If he had periodontal disease, he may well have given you the bacteria that cause periodontal disease. As you grew up, you continued to acquire new mouth bacteria – and to share yours – through such activities as sharing eating utensils and kissing.

One type of bacteria that is particularly problematic is Streptococcus mutans, often shortened to S. mutans. (The Streptococcus genus of bacteria also includes S. pneumoniae, which can cause strep throat, ear infections, and bacterial pneumonia.) Once inside the mouth, S. mutans settles in and starts to pump out a sticky substance that protects the colony of bacteria on the teeth, gums, cheeks, and tongue. This sticky coating, known as a biofilm, is designed to resist disruption by substances like toothpaste and mouthwash. The coating also allows communication between bacteria that live together. As the colony grows, other species of bacteria and other organisms (such as yeasts) are invited in. Up to 700 species of microorganisms are known to reside in the mouth of every person. Some of these species contribute to disease, while others are neutral or may even clean the place up a bit.

Depending on the particulars of your immune system (which is affected by many factors, from your genes to who kissed you first), you may be naturally susceptible or resistant to different oral diseases. If your immune system is great at fighting against cavity-causing germs but not against those that cause periodontal disease, or vice versa, you may have one but not the other. Natural immunity also explains how you can be cavity-free while your sibling, who eats the exact same diet as you and brushes better, still gets cavities. Mechanical removal of biofilm is just one factor at play in the prevention of oral disease.

Brushing and flossing are effective at breaking up the colonies in the mouth, but even people who are excellent at mechanically removing biofilm cannot reach everywhere, so there are always varying amounts of germs left on the teeth and gums. Germs are very small, and an entire colony can survive within a very small piece of biofilm. Because it’s so hard to manage biofilm through mechanical removal alone, it is important to look beyond brushing and flossing. And one of the newest options to support oral health is oral probiotics.

Probiotic basics

According to the National Center for Complementary and Alternative Medicine, part of the National Institutes of Health, probiotics are live microorganisms (in most cases, bacteria) that are similar to beneficial microorganisms found in the human gut. They are also called “friendly bacteria” or “good bacteria.” Probiotics are available to consumers in both foods and dietary supplements. Yogurt and other fermented foods are the main sources of naturally occurring probiotic bacteria both in the United States and throughout the world.

While many Americans may not have been aware of the probiotics in yogurt until the Dannon company started advertising the probiotic effects of its Activia brand, they have always been there. The “Live & Active Cultures” seal on yogurt labels refers to the probiotics contained within. The fresher the yogurt, the more viable bacteria it contains. Yogurt must contain at least 100 million living bacteria per gram (10 million for frozen yogurt) at the time it is marketed to make the claim that it contains live cultures.

While yogurt has always contained certain live cultures, adding specific strains of bacteria to yogurt or other foods solely for their effect on human health is a relatively new idea. Originally, bacteria were added in the yogurt manufacturing process to metabolize the lactose in pasteurized milk, causing the milk to thicken and become yogurt. In a happy coincidence, those cultures also contributed to the colony of beneficial bacteria in the gut. But now, “good” bacteria are added to a variety of food products that are advertised specifically as “probiotic.”

Some foods with added probiotics (and some probiotic supplements) also contain a prebiotic to act as food for the bacteria. A prebiotic is different from a probiotic. According to The American Journal of Clinical Nutrition, “A prebiotic is defined as a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon.” In other words, prebiotics are substances that promote the growth of healthy bacteria, while probiotics are healthy bacteria. Prebiotic ingredients may serve a useful purpose, and some have health benefits of their own, but they are not a necessary component of probiotics.

Oral probiotics

Just as the probiotics in yogurt are taken to improve gut health, oral probiotics are taken with the intention of improving mouth health by making the oral biofilm more healthful.

Oral probiotics are the products of recent research on the various strains of oral bacteria. One researcher, Dr. Jeffrey D. Hillman, was working on developing a vaccine against cavities when he noticed that some people in Europe drank a small probiotic supplement after lunch every day. It dawned on him that people might be willing to take a daily oral probiotic (as an alternative to a vaccine, which wasn’t coming along very well). Dr. Hillman isolated three particular types of bacteria from healthy mouths and grouped them together to produce a supplement.

Hillman’s bacterial mix is called ProBiora3, and it is found in the consumer products Evora-Pro and Probiotic Smile. This is the only oral probiotic containing strains of bacteria cultivated from the teeth of healthy people. In his research, Dr. Hillman found that his bacterial mix crowded out the cavity-causing bacteria that usually start forming a biofilm in the mouth. This new mix of bacteria didn’t pump out as much of the sticky substance, so the bacteria couldn’t form a functioning biofilm very easily. The probiotic blend reduced biofilm even in places where a brush and floss couldn’t reach.

The benefits of oral probiotics have been confirmed in other studies. One 2009 trial found that two strains of bacteria, taken together, reduced bleeding in the gums of participants upon being probed. Participants had moderate gum inflammation but were otherwise healthy; none were known to have diabetes. The probiotic mix also reduced the level of cytokines in the gums, a measure of inflammatory response.

For information about other oral probiotics, see “Oral Probiotics on the Market.”

What to consider

For healthy people, oral probiotics are safe. But because probiotics are live bacteria, they should not be used by people whose immune systems are compromised. That includes people who are undergoing chemotherapy and those who have HIV/AIDS. There are other conditions that may negatively affect the immune system; if you have any concerns about your immune health, speak to your doctor about whether oral probiotics are safe for you. If they are not, and because immune-compromised people often need to take extra measures to manage their oral biofilm, products containing xylitol may be a good alternative to try. Xylitol is a sugar alcohol used in some sugar-free gums and oral care products. It cannot be metabolized by the bacteria in the mouth, so it inhibits their growth.

When looking at the labels of oral probiotics, there are several factors to consider, including the following:

• Where are the bacteria from? Look for an oral probiotic that is sourced from healthy mouths. Probiotics that use gut bacteria don’t seem to be of great benefit to oral health.

• How is the product taken? A good oral probiotic should dissolve in the mouth; simply swallowing it won’t do much for oral health.

Good oral probiotics are freeze-dried, meaning that the bacteria are in suspended form but will become reanimated in the presence of moisture (such as saliva). Freeze-drying is ideal for all probiotic supplements that are not added to food, since without a source of nutrients, non-freeze-dried bacteria will die. (Because oral probiotics are meant to colonize the mouth rather than the digestive tract, they are not added to foods such as yogurt.) Freeze-drying may lead to a more expensive product, but these products tend to be much more effective and stable on store shelves.

The best time to start taking oral probiotics is right after a professional dental cleaning. That way, the new-to-you bacterial strains will be able to establish a foothold and crowd out more harmful bacteria. The scientists who make ProBiora3 recommend at least 90 days of daily use, but there’s really no reason to stop using oral probiotics if you feel they are benefiting you.

That said, it can be hard to determine whether the benefits of products like probiotics are worth the cost, since so many factors can have an impact on oral health. But for comparison, independent studies by two insurance companies found that people with diabetes could save $2,000 a year in medical costs just by seeing a dental hygienist for preventive care. If oral probiotics can deliver even a fraction of the benefits that regular dental cleanings do, they will be well worth the cost.