Tooth-friendly diet: These foods strengthen teeth and the gut microbiome

Figure 1: Diet has a greater influence on oral health than many people realise. A mouth-healthy diet benefits the gut microbiome and overall health in many ways.

That too much sugar damages the teeth is well known. But did you know that you can strengthen your oral health through the right diet? In this blog post you will learn why the typical Western diet increases the risk of caries and periodontitis and how you can counteract this with a tooth-friendly diet. We also present the six principles of a mouth-healthy diet and examine the close connection between oral health and the gut microbiome. Finally, we give you six practical tips to easily and sustainably support your oral health in everyday life.

Why focus on a tooth-friendly diet?

Figure 2: A tooth-friendly diet can supply the teeth with important nutrients and strengthen the oral microbiome.

When people think of “healthy teeth”, many first consider regular toothbrushing, flossing, professional dental cleaning or check-ups at the dentist. The impact of diet on dental and oral health is often underestimated, yet it plays a decisive role. Certain nutrients can specifically support oral health: mineral-rich foods containing calcium and phosphate promote remineralisation and strengthen tooth enamel, making it more resistant to acid attacks. Vitamins (e.g. vitamin C and vitamin D) also make an important contribution to oral health. These vital nutrients have anti-inflammatory effects, strengthen the gums and support local immune defence.¹

In addition, what we eat significantly influences the oral microbiome. A balanced, tooth-friendly diet promotes beneficial bacteria and helps stabilise the microbial balance. When the oral flora is in balance, pathogenic microbes have a much harder time multiplying. This can effectively reduce the risk of common diseases of the teeth and oral cavity (e.g. caries, periodontitis or gum inflammation). Because the oral microbiome is closely linked with other areas of the body, a tooth-friendly diet has effects beyond the mouth. It can also positively influence systemic processes and is associated, among other things, with conditions such as type 2 diabetes, cardiovascular disease and obesity.

Tooth-friendly nutrition is therefore much more than mere oral care: it acts as a preventive tool that not only helps prevent dental disease but also supports overall health in the long term.

The effects of the “Western Diet” on dental and overall health

Our environment – especially the social environment – shapes our eating habits in a lasting way. In Western countries, the range of foods available today is enormous. However, it is not just the wide choice that is problematic, but rather the aggressive promotion of industrially processed foods. These products strongly stimulate human reward mechanisms, particularly the dopamine system, and thus encourage excessive consumption. This consumption has negative effects on almost all organs – including oral health – and can lead to health problems. Advertising and the availability of such products make it difficult for people to control or reduce their intake. The targeted marketing and availability of foods that foster addiction and push people towards a “Western Diet” is a major problem.

Particularly harmful to dental and overall health are primarily:

• sugary foods and drinks
• acidic foods
• highly starchy, refined products
• highly processed foods that no longer contain fibre
• trans fats
• alcohol and tobacco

Sugar in particular has a high potential in this context to influence eating behaviour and to strengthen the desire for repeated consumption.

At the same time, such a diet, often referred to as the “Western Diet”, only partially meets actual nutrient requirements. In the long term, consumption of highly processed and sugar-rich foods, refined flour and saturated fats can lead to a kind of “micronutrient fasting” – with potentially negative health consequences. Modern eating habits are associated with a range of chronic diseases. These include, among others, type 2 diabetes, obesity, metabolic syndrome, inflammatory bowel diseases and systemic inflammatory processes.²

How do modern eating habits affect teeth and gums?

But what does the “Western Diet” specifically mean for our oral health? In short: it favours pathogenic processes in the mouth. Sugar serves as food for certain bacteria. The microorganisms then produce acids that attack the enamel and significantly increase the risk of caries.³ At the same time, the oral microbiome can easily fall out of balance: when pro-inflammatory microbes dominate, this promotes not only caries but also the development of periodontitis and other gum diseases.⁴ A diet low in fibre and micronutrients also lacks nutrients essential for oral health, such as calcium and phosphate, which can impair enamel resistance and immune defence in the mouth.⁵

The six principles of a mouth-healthy diet

Figure 3: Those who follow the six principles of a mouth-healthy diet according to Wölber and Tennert create a solid foundation for the long-term health of teeth and gums.

In their recommended book “Die Ernährungszahnbürste” Prof. Dr. Johan Wölber and Prof. Dr. Christian Tennert define six central principles of a mouth-healthy diet. According to the authors, the six elements are intended as a guide to make daily food choices easier. In studies, gingival inflammation was reduced by more than 50 per cent within four weeks through this mouth-healthy diet.⁶ In addition, caries-associated bacteria were significantly reduced in study participants.⁷

The following section briefly describes each principle and its effects on oral health. In addition to teeth and gums, many other areas of the body can benefit from these recommendations.

1. Low glycaemic

A low-glycaemic diet focuses on foods that cause blood sugar to rise slowly and moderately. The so‑called glycaemic index (GI) describes how much and how quickly a carbohydrate-containing food affects blood glucose. Foods with a high glycaemic index – such as free sugars, refined flour products or confectionery – lead to a rapid increase in blood sugar. As a result, more insulin is released, which regulates the transport of glucose from the blood into the body’s cells. In addition, insulin promotes the storage of excess energy as fat and can thus contribute to weight gain in the long term.

Another disadvantage of high sugar consumption is that it promotes the development of caries, inflammatory gum diseases, overweight and cardiovascular diseases.⁸ A low-glycaemic diet counteracts these effects. More stable blood sugar levels lead to more even energy supply, longer-lasting satiety and improved insulin sensitivity.⁹

2. High in fibre

Dietary fibre is known for a wealth of potential health benefits: among other things, it influences satiety, bowel movements and nutrient absorption. Studies also show protective effects of increased fibre intake on cardiovascular disease, obesity, hypertension, type 2 diabetes, certain cancers and mortality risk.¹⁰ The German Nutrition Society (DGE) recommends healthy adults consume at least 30 grams of fibre per day.¹¹ Wild populations consume 100–150 grams of fibre per day.

Fibre benefits oral health primarily because of its texture: most high-fibre foods such as raw vegetables, fruit or wholegrain products require intensive chewing, which increases saliva flow. Saliva in turn washes sugar from the teeth and remineralises tooth tissue – two factors essential for caries prevention.¹² It is therefore not surprising that average fibre intake can be a reasonably good predictor of an individual’s caries risk.¹³

3. Rich in micronutrients

Not only fibre but also micronutrients are often lacking in the modern Western diet. Although micronutrients such as vitamins, minerals and trace elements are not required for energy production like macronutrients, they play a key role in many cellular processes and in the immune system. With regard to oral health, particular attention should be paid to adequate supplies of calcium and phosphate as well as vitamin D and vitamin C. Vitamin D is an important regulator of calcium metabolism and helps incorporate calcium into bone and tooth tissue.¹⁴ Adequate vitamin C intake can significantly reduce the risk of caries, gingivitis and periodontitis.¹⁵

4. Prebiotic

Prebiotics are the food for probiotic bacteria that have a positive effect on human health. Prebiotics – mainly fibres – pass undigested into the large intestine where they are fermented and converted into short-chain fatty acids. These contribute to satiety and have strong anti-inflammatory effects. In contrast, most ingredients of the “Western Diet” serve as ideal food for pathogenic bacteria in our oral and gut microbiomes. For example, free sugars are metabolised by cariogenic bacteria in the oral biofilm into organic acids. These cause a drop in pH in dental plaque, leading to the dissolution of minerals from the enamel and promoting the development of caries.¹⁶

5. Rich in omega‑3

An adequate intake of omega‑3 fatty acids is associated with less severe periodontitis, fewer gum inflammations and better tooth retention. Unlike the generally pro-inflammatory omega‑6 fatty acids, omega‑3s are attributed anti-inflammatory and inflammation-resolving properties. The German Nutrition Society (DGE) recommends eating oily sea fish once or twice a week, which is an excellent source of long-chain omega‑3 fatty acids.¹⁷  Alternatively, omega‑3 can be supplemented as algal oil or obtained from plant foods such as flaxseed/seeds and oil, hemp seeds/oil, walnuts or chia seeds.

6. Evolutionary

According to Wölber and Tennert, our current diet is far removed from a healthy, species-appropriate way of eating. As a primate species, a predominantly plant-based diet with relatively few animal foods is evolutionarily ideal for humans. The shift to settled agriculture around 15,000 years ago and the early keeping of livestock fundamentally changed our typical diet. The diversity of primary plant compounds was replaced by large quantities of cereal products as well as meat and dairy. Later, many industrially processed and sugar-rich foods were added. Products to which sugar has been added, in particular, carry an increased risk for the development of caries and gum inflammation and should therefore be avoided or consumed very sparingly from an oral health perspective.

How are oral health and the gut microbiome connected?

Figure 4: The oral microbiome in the mouth and the intestinal microbiome in the gut are closely connected. If one of the two areas is out of balance, the other area may also suffer.

Our diet significantly influences both dental and gut health. Both areas host complex microbial ecosystems – the oral microbiome in the mouth and the intestinal microbiome in the gut. The oral cavity alone harbours over 700 different bacterial species. Every day, billions of these microorganisms are swallowed with saliva and pass from the mouth into the digestive tract. Recognising this process makes it clear that the oral and intestinal microbiomes are closely linked – together they form the oral‑intestinal microbiome system.

When the oral microbiome is out of balance, as in periodontitis, more disease-promoting bacteria and their metabolic products can reach the gut. There they can influence immune responses and subsequently contribute to various conditions such as Crohn’s disease, ulcerative colitis or type 2 diabetes. Conversely, the gut microbiome also affects oral health: a disturbed gut microbiome can impair the immune system, amplify inflammatory processes and increase susceptibility to gum disease.

The good news is that many components of a tooth-friendly diet simultaneously support the gut microbiome. Above all, a high-fibre diet, reduced consumption of sugar and heavily processed foods, and regular consumption of probiotic foods (e.g. sauerkraut, kimchi, kefir) can positively influence both oral and gut health.

From raw carrots to wholegrain bread: a selection of tooth-friendly foods

Figure 5: Eating foods that require intensive chewing supports oral health by stimulating saliva production and mechanically cleaning the teeth.

A tooth-friendly diet supplies tooth tissue with important minerals and prevents the mouth from becoming a breeding ground for potentially pathogenic bacteria. The most important nutrients for oral health include calcium, phosphorus, fluoride, vitamin C, vitamin A and vitamin D. In addition, sufficient intake of fibre and omega‑3s should be ensured. Foods that require intensive chewing are also ideal, as vigorous chewing stimulates saliva production, which additionally cleans the teeth and promotes remineralisation.

The following list contains foods that meet one or more of the above criteria and are therefore particularly suitable for a tooth-friendly diet:

• seasonal and regional organic vegetables (e.g. leafy greens and cruciferous vegetables such as cauliflower or broccoli)
• raw vegetables and fruit (e.g. apples, carrots, celery)
• wholegrain products (e.g. wholemeal bread, wholegrain pasta)
• legumes (e.g. lentils, chickpeas)
• dairy products (e.g. milk, yoghurt, cheese)
• nuts and seeds (e.g. almonds, chia seeds)
• sustainably caught sea fish or algal oil

Tooth-friendly eating in everyday life: 6 tips for strong, healthy teeth

Our eating and drinking habits influence oral health more than many people realise. Proper oral hygiene between meals also plays an important role in maintaining a healthy oral flora. The following everyday tips can help support oral health and effectively prevent diseases of the teeth and gums:

• Watch out for hidden sugar when shopping: For caries prevention, it is important to keep sugar intake as low as possible. It is well known that sweets, ice cream and sweet pastries are high in sugar. However, there are many products that appear “healthy” at first glance but contain as much sugar as gummy bears. This is especially true for dressings, fruit yoghurt, processed meats, ketchup, sauces and many ready meals. Instead of fruit yoghurt, for example, you can enjoy unsweetened yoghurt with berries or fresh fruit.
• Drink only unsweetened beverages: Drinks such as soft drinks, lemonades, fruit juices and cocktails often contain high amounts of sugar and are therefore risk factors for oral health. However, sugar‑ and calorie‑free “light” versions are not really tooth‑friendly alternatives either. They contain organic acids that significantly lower the pH in the mouth and thus promote demineralisation of the enamel and erosive damage to tooth tissue. Water or unsweetened tea is a far better choice for meeting fluid needs.
• Snack preferably at main meals: For oral health, not only the amount of sugar consumed matters but also how often you snack. If sweet foods are eaten repeatedly throughout the day, cariogenic bacteria constantly receive new nourishment. If the urge for something sweet becomes strong, it is preferable to snack during or after a meal. This way the teeth are not repeatedly exposed to small amounts of sugar and blood sugar remains more stable.
• Sweeten with almond butter and cinnamon: Instead of refined sugar, natural alternatives such as almond butter or cinnamon can be used. Almond butter provides healthy fats and minerals, while cinnamon gives a pleasant sweetness without burdening the enamel. This way you can reduce sugar intake without sacrificing flavour.
• Avoid very sticky foods: Caramel, dried fruit, chewy sweets and other sticky foods adhere particularly long to the teeth. This prolongs the exposure time of sugar and acids to the enamel, increasing the risk of caries. After consuming sticky foods, pay particular attention to thorough cleaning of the teeth and mouth.
• Do not brush your teeth immediately after consuming acidic foods: After consuming acidic foods and drinks (e.g. citrus fruits, soft drinks, vinegar, wine and sparkling wine) the enamel is temporarily softened. Brushing immediately in this state can wear away the outer layer of enamel, which can make teeth more sensitive. Therefore, it is advisable to wait at least 30 minutes after consuming acidic items before brushing your teeth.

Disclaimer

This article does not replace treatment by a qualified practitioner. The basis of this contribution is studies and current literature. It must not be used for self-diagnosis or self-treatment. Discuss any inspirations from this article with a practitioner you trust.

Biography

Katharina Korbach regularly writes blog posts on medicinal plants and natural substances for Narayana Verlag. She developed an interest in language early on and began writing her own literary texts. A severe illness during her final school exams prompted an intensive engagement with health and nutrition topics that continues to this day. After repeated failures of conventional medical treatments, she chose a more self‑efficacious, naturopathic therapeutic approach. A plant‑based diet was an important key on her path to recovery.

Katharina studied Cultural Studies (B.A.) and Applied Literary Studies (M.A.). In 2022 she published her debut novel “Sperling” with Berlin Verlag. She now lives in Berlin as a freelance author, medical editor and lecturer. She prefers to spend her free time with friends or at barre training. She also loves travelling and trying out new vegan recipes.

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21 April 2026