Biochemical Interactions in Dental Biofilms

Dental biofilms are structured microbial communities adhering to the tooth surface and embedded in a self-produced extracellular matrix. Initial colonisers such as streptococci adhere to the acquired pellicle and secrete extracellular polymeric substances that scaffold subsequent attachment events. Within this matrix, communal metabolism converts dietary carbohydrates into organic acids, leading to local pH drops that select for aciduric, cariogenic species. Interactions between acid producers and alkali-generating commensals, notably via the arginine deiminase system, modulate pH homeostasis and influence demineralisation–remineralisation cycles. Metabolic cross-feeding between lactate producers and secondary consumers further shapes community composition, while quorum sensing coordinates biofilm maturation, stress responses and extracellular enzyme production. Host factors, including salivary flow and immune mediators, interplay with microbial biochemistry to determine biofilm resilience and the balance between oral health and disease.

Research from Nature Portfolio

Studies have defined how arginine supplementation shifts microbial equilibrium by enriching alkali producers and suppressing aciduric pathogens, thereby restoring a health-associated pH profile in biofilm models. Investigations into combined arginine–fluoride formulations have revealed synergistic disruption of multi-species biofilm architecture, maintenance of ecological homeostasis and downregulation of key virulence genes in cariogenic streptococci. Additionally, synbiotic approaches pairing probiotic Lactobacillus rhamnosus with L-arginine have demonstrated enhanced probiotic viability, significant inhibition of Streptococcus mutans biofilm formation and reduction of lactic acid production, underscoring the potential of strain-specific, mixed-microbial therapies in caries prevention.

Biochemical Interactions in Dental Biofilms publication trend

The graph below shows the total number of articles in biochemical interactions in dental biofilms across all publications each year (not limited to Nature Index journals).

Technical terms

Extracellular polymeric substances: matrix of polysaccharides, proteins and nucleic acids that binds biofilm cells and mediates adhesion.

Acidogenic: describing bacteria or processes that generate acids from carbohydrate metabolism.

Aciduric: describing organisms that tolerate or thrive in low-pH conditions.

Arginine deiminase system (ADS): metabolic pathway that catabolises arginine to produce ammonia, raising local pH.

Metabolic cross-feeding: exchange of metabolic by-products between different microbial species within a biofilm.

Quorum sensing: cell-to-cell signalling mechanism by which bacteria regulate gene expression in response to population density.

References

1. Manipulating the diseased oral microbiome: the power of probiotics and prebiotics. Journal of Oral Microbiology (2024).
2. Heterogeneous lineage-specific arginine deiminase expression within dental microbiome species. Microbiology Spectrum (2024).
3. Spatiotemporal monitoring of a periodontal multispecies biofilm model: demonstration of prebiotic treatment responses. Applied and Environmental Microbiology (2023).
4. Ecological Effect of Arginine on Oral Microbiota. Scientific Reports (2017).
5. The combined antimicrobial effect of arginine and fluoride toothpaste. Scientific Reports (2019).
6. Effect of a novel synbiotic on Streptococcus mutans. Scientific Reports (2020).