Revealing How Allulose Influences Oral Microbiota and Biofilm Formation via Cariogenic Potential

The oral risk that formulators often miss

If you formulate sugar-free confectionery or oral-care products, you have a new reason to look at allulose. A 2025 study in Frontiers in Cellular and Infection Microbiology (DOI: 10.3389/fcimb.2025.1670139) compared allulose with common sugars and sugar alcohols. The results put allulose in a surprising position. It behaves more like xylitol and erythritol than like sucrose. That is a big deal for product developers.

Dental caries is not simply a sugar problem. It is a microbial problem. Oral bacteria feed on carbohydrates, produce acid, and build biofilms. Streptococcus mutans is the main driver. It uses sucrose to synthesize sticky extracellular polysaccharides (EPS). Those polysaccharides create a dense scaffold, trapping acid against enamel. If a sweetener doesn’t feed that process, it has low cariogenic potential. Allulose appears to fit that profile.

What the researchers did

The team exposed oral microbiota to allulose, sucrose, glucose, fructose, xylitol, and erythritol. They measured bacterial growth, acid output, biofilm architecture, and expression of virulence genes in S. mutans. They also looked at how the microbial community shifted in the presence of allulose.

The results were clear. Allulose supported lower bacterial growth and acid production than the three conventional sugars. Its performance resembled the non-fermentable sugar alcohols. Sucrose produced thick, EPS-packed biofilms with microcolonies and dome structures. Allulose did not. Biofilms formed under allulose conditions lacked that dense scaffold and maintained higher microbial diversity.

Key findings

The most striking number is 99%. Acid production in the allulose group was 99% lower than in the sucrose group. That is not a small reduction. It changes the risk equation for formulators.

Allulose also downregulated three key cariogenic virulence genes in S. mutans: gtfD, ldh, and atpD. Those genes control glucan synthesis, lactate production, and acid tolerance. Suppressing them reduces both the bacteria’s ability to stick and its ability to demineralize enamel.

Sweetener	Bacterial growth	Acid output	Biofilm architecture
Sucrose	High	High (reference)	Dense EPS microcolonies, dome-shaped
Glucose / fructose	High	High	Not described in this paper
Allulose	Low	Low; 99% lower than sucrose	No dense EPS; higher microbial diversity
Xylitol / erythritol	Low	Low	Similar non-fermentable profile

What it means for formulators

This study gives you a microbiological rationale for using allulose in oral-care and sugar-free products. It is not just a bulk sweetener. It appears to resist the cariogenic cascade at multiple points: less bacterial growth, less acid, less EPS, and lower virulence gene expression.

That matters for chewing gum, mints, lozenges, and confectionery. In those formats, sweeteners sit in the mouth long enough to influence plaque pH. Allulose could help maintain a more diverse oral microbiota instead of feeding the same acid-producing organisms. That is a meaningful differentiation point for ingredient buyers.

One caution: this is an in vitro study, not a clinical caries trial. It does not prove that allulose prevents cavities in humans. It does suggest that allulose has low cariogenic potential in the same experimental context as xylitol and erythritol.

FAQ

Is allulose cariogenic?

In this model, no. Allulose supported less bacterial growth and acid production than sucrose, glucose, and fructose. Its acid production was 99% lower than sucrose. That places it close to xylitol and erythritol in cariogenic potential.

Can I replace sucrose with allulose in a formulation?

This paper does not address sensory or processing issues. It addresses microbiology. From that angle, allulose behaves more like a non-fermentable polyol than a conventional sugar. You will still need to test sweetness, texture, and stability in your specific product.

Does allulose prevent cavities?

No clinical evidence yet. Low cariogenic potential is not the same as cavity prevention. The current data point is encouraging, but clinical validation is needed before making anti-caries claims.

The dental risk of a sweetener depends on what oral bacteria do with it. Sucrose feeds the plaque-forming, acid-producing machinery. Allulose does not appear to do that. For formulators, that makes allulose a more interesting option than its calorie count alone suggests.