Is Sugar Bad for Your Oral Bacteria?

By Jiri Kaloc

What you eat influences the microbes living in your gut. Fibre feeds beneficial bacteria while sugar feeds the ones that cause problems. New research suggests that sugar intake might influence the microbiome directly in your mouth. What does it mean when it comes to sports drinks and energy gels you consume on the bike?

What’s the oral microbiome?

We know that the collection of bacteria in our gut called the microbiome is closely connected to health and disease risk. Research shows that this microbiome is not exclusive to the gut. In fact, every part of your body has its own microbiome, including your mouth. Over 700 different species of bacteria have been identified in the oral cavity. The average person’s mouth hosts more than 250 species at a time.

Scientists from the University of Buffalo decided to explore how food – and sugar intake in particular – impacts the balance of the oral microbiome and how it influences disease risk. Their study is the first to examine sugar intake and the subgingival microbiome, meaning they were taking samples from under the gums, rather than just samples of saliva.

“This is important because the oral bacteria involved in periodontal disease are primarily residing in the subgingival plaque. Looking at measures of salivary bacteria might not tell us how oral bacteria relate to periodontal disease because we are not looking in the right environment within the mouth,” said study first author Amy Millen, PhD.

Sugar and high glycaemic food are disrupting your microbiome

The researchers found a connection between poor oral health and the intake of foods with high sugar content and glycaemic load such as doughnuts, soft drinks, breads and non-fat yoghurts. They showed that eating these foods benefits the growth of several bad bacteria. For example, Streptococcus mutans, which is connected to tooth decay and several types of cardiovascular disease, and Leptotrichia spp., which is connected to Gingivitis, a common gum disease.

“We examined these bacteria in relation to usual carbohydrate consumption in postmenopausal women across a wide variety of carbohydrate types: total carbohydrate intake, fibre intake, disaccharide intake, to simple sugar intake. No other study had examined oral bacteria in relation to such a broad array of carbohydrate types in one cohort. We also looked at associations with glycaemic load, which is not well studied in relation to the oral microbiome,” said Amy Millen.

Should you avoid sugar?

The authors of the study are saying that these findings are important but not yet conclusive enough to make definitive statements.

“As more studies are conducted looking at the oral microbiome using similar sequencing techniques and progression or development of periodontal disease over time, we might begin to make better inferences about how diet relates to the oral microbiome and periodontal disease,” explained Amy Millen.

For those who want to be on the safer side, it might be a good idea to reduce sugar intake, even if you aren’t seeing problems now. Whether it’s sugar to fuel your cycling efforts or sugar in a sweet dessert, your oral microbiome keeps the score.