Blog | Reading Time 5 minutes

Oral Health: How Does Your Oral Microbiome Evolve?

Oral Health: How Does Your Oral Microbiome Evolve?

On World Oral Health Day, we want to raise awareness on the importance of oral health, as it can contributes to maintenance of health and wellness but also to various health conditions. This article will embrace an important theme: how do the millions of bacteria in your mouth evolve from infancy to adulthood?

The Importance of Caring for Kids Oral Health

At birth, the oral cavity is most likely sterile. Shortly after birth, with the first feeding, some pioneer species start to colonize the mouth. These pioneer species are usually Streptococci, which bind to mucosal epithelium. The metabolic activity of the pioneer community then alters the oral environment to facilitate colonization by other bacterial species. Streptococcus salivarius is dominant in infants and may represent up to 98% of the total flora. By a child’s first birthday and the first teeth, further niches are provided for bacterial colonization, including dental enamel and the gingival crevice. Together with eruption of teeth, the appearance of specific flora able to colonize hard non-epithelial surfaces occurs. Bacteria such as Streptococcus mutans selectively colonize enamel surfaces, forming dental plaque, while other anaerobic bacteria colonize gingival crevices. Therefore, dentists recommend introducing a mouth hygiene routine from an early age.

The Challenges of Teens Oral Microbiota Balance

At puberty, the oral microbiota continues to evolve, transitioning to an adult flora. Spirochaetes, Veillonella, Prevotella, and black-pigmented Bacteroides can be found with higher prevalence during this period of life. Even with all the goodwill in the world, as kids are becoming teens, their dental hygiene is not always optimal, neither properly implemented. It was demonstrated that teens are more prone to dental or gum health issues as scientists have exposed a higher prevalence of dental plaque accumulation than in prepubescent children or adults. This may be linked to the increase in sex hormones during puberty and the teens’ lifestyle (repetitive high sugar intake, soft sticky food consistency) and lack of consistent dental hygiene. All good reasons to keep up the good oral health habits instilled in childhood.

In Adulthood the Oral Flora offers a Natural Protection

The oral microflora becomes more and more diverse over time until it reaches an equilibrium and remains stable although some external factors can alter this balance. At adult age, under normal conditions and with proper oral hygiene, the oral flora is balanced and works as a part of the barrier effect in the immune system. However, this oral microflora balance can be altered by lifestyles: poor dental hygiene, a diet rich in sugar, smoking or alcohol consumption can have a significant impact on the oral microflora. Learn more about the best dental health’s practice to support your oral health in our previous blog article.

Even When You’re Toothless, Bacteria Don’t Take a Rest

The simple fact of aging has direct and indirect effects on the oral microbiota homeostasis. The regular age-related loss of teeth represents the last major bacterial alteration. At this stage, the oral microbiota becomes similar to an infant’s microflora before tooth eruption, given a similar environment due to the lack of hard surfaces.

With the usage of a prosthetic appliance, the oral microbiota can once again be disrupted as new niches are provided, giving way to new microorganism species, particularly Candida species, to take over this new playground. From 70-year-old onwards, it was also demonstrated that there is a high prevalence of Staphylococcus aureus and Lactobacilli.

Oralis SB, One of The Most Documented Probiotic for Oral Health

What can you do to put all the chances on your side to take care of your oral health, all life long? Various solutions exists and probiotics now have documented modes of actions for consideration as a natural solution for oral health – you can read all about it in our previous blog article. Lallemand Health Solutions offers ORALIS SB, the most documented probiotic for oral health, supported by a solid clinical background on the maintenance of healthy teeth and gums. Two clinical studies demonstrated that ORALIS SB helped maintain dental health in healthy adults and children through the control of bacteria in the mouth. Five other clinical studies on gum health showed increased tooth scores and gum health in participants.


Contact us for your oral health project!


Samaranayake, L., & Matsubara, V. H. (2017). Normal Oral Flora and the Oral Ecosystem. Dental Clinics of North America, 61(2), 199–215.
Deo, P. N., & Deshmukh, R. (2019). Oral microbiome: Unveiling the fundamentals. Journal of oral and maxillofacial pathology: JOMFP, 23(1), 122.

Published Mar 22, 2022 | Updated Mar 7, 2024

Need specific information?

Talk to an expert