Quick summary: Maintaining a diverse oral microbiome containing roughly 700 types of bacteria is fundamental to systemic well being, as these microbes protect against infection and regulate essential functions like digestion. Research indicates that shifting towards a fibre rich plant based diet acts as a natural prebiotic to support beneficial bacteria, moving clinical focus away from reactive treatments for toothache and towards holistic prevention. Recognising the mouth as a gateway to full body health is a critical priority for public policy and healthcare practice, as oral diseases are increasingly linked to serious systemic conditions including diabetes and cardiovascular health.
As National Smile Month begins, experts are highlighting a surprising fact: the human mouth contains roughly 700 types of bacteria, most of which play beneficial roles. Rather than signalling poor hygiene, a diverse oral microbiome helps protect against harmful microbes, supports digestion, and maintains oral health.
Running from 11th May – 11th June, National Smile Month promotes a key message: Prevention is better than cure. Despite this, many people still focus on oral health only when problems such as toothache, bleeding gums, or bad breath arise, by which point damage may already have begun.
Understanding the oral microbiome
The mouth is a complex ecosystem known as the oral microbiome, made up of bacteria, fungi, viruses, and other microorganisms. Scientists have identified more than 700 bacterial species living across the teeth, gums, tongue, and cheeks.
These microbes play an active role in maintaining health. Beneficial bacteria help regulate harmful species, support gum tissue, stabilise pH levels, and contribute to the body’s natural defences. When this balance is disrupted by factors such as high sugar intake, poor diet, or lifestyle habits, harmful bacteria can dominate, increasing the risk of tooth decay and gum disease.
Oral health and overall well-being
The importance of oral health extends beyond the mouth.
Dr Maria Papavergos, known as “The Lifestyle Dentist,” explains: “This National Smile Month, let’s recognise oral health as the foundation to a happy smile. A healthy mouth links to a healthy body, with oral disease increasing risks of systemic disease from Alzheimer’s disease to diabetes and even cancer. Viewing the mouth through a holistic lens, balancing nutrition and lifestyle with oral hygiene, underpins a smile that looks good, feels good and reflects full body health.”
Diet and the role of fibre
For decades, oral health advice has focused on reducing sugar, which fuels harmful bacteria such as Streptococcus mutans that produce enamel-eroding acids.
However, experts say diet is not just about restriction. Increasing evidence shows that fibre-rich, plant-based foods support a healthier oral microbiome.
Fibre contributes in two key ways
- It stimulates saliva production through chewing, helping neutralise acids, remove food particles, and strengthen enamel
- It acts as a prebiotic, feeding beneficial bacteria and helping them outcompete harmful microbes
Foods that support oral health include
- Vegetables such as broccoli, carrots, and leafy greens
- Fruits including apples and bananas
- Whole grains such as oats and brown rice
- Legumes like lentils and chickpeas
- Prebiotic-rich foods such as onions, garlic, leeks, and asparagus
Highly processed diets that are low in fibre and high in refined carbohydrates are linked to microbial imbalance, while whole, plant-based foods promote microbial diversity.
Emerging role of oral probiotics
Oral probiotics are gaining attention as a way to support the microbiome. Unlike traditional products that aim to eliminate bacteria, these introduce beneficial strains to restore balance.
Strains such as Lactobacillus reuteri and Lactobacillus paracasei have been studied for their potential to compete with harmful bacteria, support gum health, reduce plaque, and improve breath.
Prevention and daily habits
Experts recommend simple steps to maintain oral health
- Brush and floss regularly
- Reduce sugar intake
- Eat a fibre-rich diet
- Stay hydrated
- Consider microbiome-friendly oral care products
Samangi Wije sena, microbiologist and co-founder of Luvbiotics, said: “One of the key messages of National Smile Month is the importance of building healthy habits early and maintaining them consistently. However, it’s never too late to make positive changes. By shifting focus from treatment to prevention, and from surface-level care to internal balance, individuals can take greater control of their oral health.”
A shift towards holistic care
Experts say the growing understanding of the oral microbiome is reshaping how oral health is managed. Rather than focusing solely on eliminating bacteria, the emphasis is shifting towards maintaining balance through diet, lifestyle, and targeted care.
The mouth is not separate from the body but a gateway to it. Understanding this connection allows for a more holistic approach to long-term health.