Oral microbiome: Plaque biofilm and Listerine in oral health

You already know how important it is to maintain a healthy oral microbiome.

But did you know that LISTERINE® can play a role in cultivating a healthy equilibrium of microorganisms in the oral cavity1? Don’t discount the part twice-daily rinsing can play in helping your patients sustain balanced oral health!



One of the most diverse microbial communities in the body is found in the oral cavity, which offers many distinct habitats for colonization (teeth, tongue, gingiva, etc.). Hundreds of bacterial species—and billions of individual bacteria—live in the human mouth.1-3 Control of dental plaque biofilm is therefore essential to the maintenance of oral health.4

A complex equilibrium among microbial species helps maintain a healthy state (eubiosis) in the oral cavity. But biological changes in the body (such as pregnancy), certain diseases (such as rheumatoid arthritis), and factors that can be modified (such as diet, glycemic control, smoking, and the use of antibiotics) may affect the risk of oral diseases (dysbiosis).5

Accumulation of biofilm threatens Eubiosis

Communities of microorganisms may adhere to one another and to surfaces, forming a biofilm—a complex, highly organized, 3-dimensional microbial colony enclosed in, and protected by, an extracellular matrix. In the mouth, changes in the composition of biofilm may cause unhealthy imbalances. For example, when large quantities of microbes accumulate as dental plaque biofilm and are not disrupted or removed, dysbiosis may occur.5

Biofilm begins to appear within minutes after mechanical cleaning.6 Microbes form a complex biofilm within days. 6

Changes within biofilm may drive dysbiosis

The makeup of a biofilm’s microbial population does not remain stable over time. Plaque biofilm colonies initially consist of gram-positive organisms. If left undisturbed, the biofilm eventually becomes more complex and shifts to a predominantly gram-negative mix.7 In addition, changes in the local environment within the mouth select organisms that are more tolerant of that environment, which, in turn, may drive further change. For example, the increased frequency of sugar intake or reduced flow of saliva expose biofilms to a more acidic environment in which acid-tolerant or acid-producing organisms thrive and populations of organisms that prefer neutral pH may struggle. This may result in dysbiosis.5

Dysbiosis may lead to disease

Plaque biofilm may contain pathogens that interfere with the immune system. In a dysbiotic environment, these may lead to gingivitis and periodontitis.5

Controlling plaque biofilm to promote health

Strategies for the prevention and treatment of periodontal diseases include both mechanical and chemical methods. Good oral hygiene, including regular brushing and flossing, is required to effectively disrupt and remove plaque biofilm. LISTERINE® aids with whole-mouth plaque control by penetrating the biofilm's extracellular matrix and killing bacteria, helping to keep the biofilm healthy.7


Educating your patients

It is important that patients understand the concept of maintaining a healthy balance of the microbiome in their mouths and the impact poor oral hygiene and smoking may have on plaque biofilms.5 Patients also need to understand that periodontal disease results from the accumulation of plaque biofilm.4

Help your patients understand that there are more ways to control plaque and gingivitis than mechanically removing plaque by brushing and flossing. Consider recommending an essential oil-based, antimicrobial mouthrinse to improve their ability to control plaque between dental visits.

References: 1. Johnson & Johnson internal study: CCSORC001793 (Serenity) 2020. 2. Dewhirst FE, Chen T, Izard J, et al. The human oral microbiome. J Bacteriol. 2010;192(19):5002-5017. 3. Chen, T, Yu W-H, Izard J, Baranova OV, Lakshmanan A, Dewhirst FE, The Human Oral Microbiome Database: a web accessible resource for investigating oral microbe taxonomic and genomic information. Database, Vol. 2010, Article ID baq013, doi: 10.1093/database/baq013. Online Open Access: 4. Kumar PS. From focal sepsis to periodontal medicine: a century of exploring the role of the oral microbiome in systemic disease. J Physiol. 2017;595(2):465-476. 5. Kilian M, Chapple ILC, Hannig M, et al. The oral microbiome—an update for oral healthcare professionals. Br Dent J. 2016;221(10): 657-666. 6. Marsh PD, Martin MV, Lewis MAO, Williams DW. Dental plaque. Oral Microbiology E-Book, Fifth edition. London: Churchill Livingstone; 2009:74-102. 7. Gurenlian JR. The role of dental plaque biofilm in oral health. J Dent