High-throughput models to investigate the ecology and control of oral biofilms

The microbial community inhabiting the oral cavity constitutes a subset of the broader human microbiome. Second only to the gut in species diversity, the oral microbiome is implicated in numerous oral and systemic diseases. These microorganisms persist within the challenging oral environment as biofilms, structures which provide protection against environmental stressors and facilitate cooperative microbial interactions. Biofilm development is influenced by numerous variables which results in inconsistency both clinically and in vivo, restricting standardisation.
In vitro modelling overcomes this with better control of experimental conditions whilst retaining the potential to predict clinical outcomes. Nevertheless, increasing the physiological relevance in these devices typically degrades throughput, thereby reducing research capacity.
The “MiTooth” platform described here is engineered with an aim of addressing this key limitation through scalable design. The model was evaluated through three different case studies, each designed to assess specific model features:
1. Evaluating the protective efficacy of topical self-assembling peptides against acid-induced enamel erosion. Analysis by X-ray microtomography revealed increased enamel demineralisation in peptide-treated teeth versus a fluoride varnish control under pH cycling.
2. Investigating how environmental parameters influence the development of defined-species biofilms. Changes to culture conditions in parallel experiments created distinct biofilm communities. Increased environmental complexity was associated with a reduced disparity between Gram-positive and Gram-negative populations in a biofilm composed of species implicated in periodontitis.
3. Assessing the effects of probiotic supplementation on periodontal biofilm formation. This study demonstrated that probiotic species can integrate into a developing defined-species oral biofilm, albeit with limited impact to composition.
Although MiTooth is limited in its long-term evaluation and ability to impose defined spatial restriction to developing biofilms, the case studies presented here demonstrate that it can be adapted to facilitate diverse research objectives. Its focus on resource efficiency and scalability positions it as a candidate tool for supporting studies into biofilm dynamics and exploring potential therapeutic targets related to oral and systemic diseases.