How Your Diet Changes Your Oral Health and Performance
A specialized diet changes the bacterial community in your mouth, but surprisingly preserves its ability to convert healthy compounds from vegetables like beetroot.
Imagine a bustling city within your mouth, home to billions of microscopic inhabitants that shape your health in ways science is just beginning to understand. This invisible ecosystem, known as the oral microbiome, does far more than just influence your dental health—it may hold the key to unlocking the performance benefits of certain foods, even when you radically change your diet. Recent research reveals a fascinating story of how a popular dietary approach transforms this community of oral bacteria while surprisingly preserving its ability to convert healthy compounds from vegetables like beetroot.
For athletes and health enthusiasts alike, the low carbohydrate, high fat (LCHF) diet has gained considerable attention for its ability to shift the body's fuel source from carbohydrates to fat. Yet this metabolic flexibility comes with a puzzling trade-off: despite enhanced fat burning, athletes often experience impaired performance during high-intensity endurance activities. The mystery lies in what scientists call "exercise economy"—the oxygen cost of movement—which curiously worsens on LCHF diets even as other metrics improve 1 .
The community of microorganisms residing in the human mouth, playing crucial roles in digestion, immunity, and nutrient processing.
A dietary approach emphasizing high fat intake while restricting carbohydrates, prompting metabolic adaptations.
At the heart of this story lies a remarkable biological pathway that connects the food we eat to our blood vessels and muscle function. Understanding this process requires exploring three key concepts:
The conversion process where dietary nitrate becomes beneficial nitric oxide via oral bacteria.
Dietary approach that shifts metabolism from carbohydrates to fat as primary fuel source.
The bacterial ecosystem in the mouth that serves as a metabolic gateway for nitrate conversion.
When we consume nitrate-rich vegetables like beetroot, spinach, or rocket, an intricate conversion process begins in our mouths. Specialized bacteria living on our tongue and throughout our oral cavity contain enzymes that reduce dietary nitrate to nitrite 2 . This nitrite is then swallowed and further converted in our stomach and bloodstream to nitric oxide (NO), a molecule with far-reaching effects in the body 9 .
Nitrate-rich vegetables like beetroot are consumed, providing the raw material for conversion.
Oral bacteria convert nitrate (NO₃) to nitrite (NO₂) using specialized enzymes.
Nitrite is swallowed and converted to nitric oxide (NO) in the stomach and bloodstream.
Nitric oxide relaxes blood vessels, improves blood flow, and enhances muscle efficiency.
The LCHF diet, typically consisting of less than 50 grams of carbohydrates per day with approximately 80% of energy coming from fat, prompts a profound metabolic adaptation 1 8 . Within days of adopting this eating pattern, the body shifts from primarily burning carbohydrates to efficiently oxidizing fat, both at rest and during exercise. This transition doubles the rate of fat oxidation during physical activity, potentially sparing limited glycogen stores 6 .
The oral microbiome represents a diverse ecosystem of bacteria, with significant variation between individuals in both the types and abundance of species present 6 . This community is remarkably sensitive to environmental influences, with diet emerging as a powerful factor in shaping its composition.
The bacteria responsible for nitrate reduction are particularly vulnerable to dietary changes, since they depend on nitrate not just for the conversion process but as an essential component of their metabolic activities 1 .
To unravel the complex relationship between LCHF diets, the oral microbiome, and nitrate supplementation, researchers designed an elegant experiment using highly trained male race walkers 1 6 .
| Aspect | High Carbohydrate (HCHO) Group | Low Carbohydrate, High Fat (LCHF) Group |
|---|---|---|
| Participant Profile | Highly trained male race walkers (Tier 3 to Tier 5) | Highly trained male race walkers (Tier 3 to Tier 5) |
| Sample Size | n = 11 | n = 13 |
| Dietary Composition | 8.5 g/kg/day carbohydrate, ~2 g/kg protein, 20% fat | <50 g/day carbohydrate, ~2 g/kg protein, 80% fat |
| Daily Energy Intake | ~40 kcal/kg lean body mass | ~40 kcal/kg lean body mass |
| Test Beverage | 140 mL beetroot juice (8.4 mmol nitrate) | 140 mL beetroot juice (8.4 mmol nitrate) |
The results revealed fascinating changes in the oral microbiome that were both pronounced and unexpected. After just five days on the LCHF diet, athletes experienced a significant reduction in oral bacterial diversity, along with noticeable changes in specific bacterial groups 1 6 .
| Bacterial Genus | Change with LCHF Diet | Associated Functions & Notes |
|---|---|---|
| Neisseria | +10% increase | Associated with periodontal health and younger age; known nitrate-reducer 1 7 |
| Fusobacteria | +3% increase | - |
| Prevotella | -9% decrease | Associated with inflammation; decreases with nitrate-rich juice in older adults 1 7 |
| Veillonella | -4% decrease | Associated with inflammation; decreases with improved oral health 1 |
Despite microbiome changes, nitrite response remained intact in LCHF group.
The preservation of nitrate reduction capacity despite reduced bacterial diversity suggests the oral microbiome displays a remarkable functional adaptability 1 .
Even when the overall community structure changes, the essential nitrate-reducing function can be maintained—possibly through the increased abundance of key nitrate-reducing genera like Neisseria observed in the LCHF group 1 .
| Parameter | High Carbohydrate (HCHO) Group | Low Carbohydrate, High Fat (LCHF) Group | Statistical Significance |
|---|---|---|---|
| Plasma Nitrite Increase | Significant increase post-beetroot juice | Significant increase post-beetroot juice | p = 0.04 (between groups) |
| Diet-Trial Interaction | Not significant | Not significant | p = 0.71 |
| Interpretation | Beetroot juice effectively raised nitrite levels | Beetroot juice effectively raised nitrite levels despite microbiome changes | Difference between groups not attributable to dietary intervention |
The implications of this research extend far beyond the world of elite athletics. The same nitrate-nitrite-nitric oxide pathway that enhances exercise performance in athletes also plays a crucial role in cardiovascular health for the general population, particularly older adults 7 .
Nitric oxide improves blood flow to the brain, supporting cognitive health.
Vasodilation from nitric oxide helps regulate blood pressure.
Improved oxygen delivery enhances muscle performance during exercise.
"Research involving older adults (aged 70-80) has shown that regular consumption of nitrate-rich beetroot juice can significantly lower blood pressure and improve cognitive function 2 . Interestingly, these benefits were accompanied by specific changes in the oral microbiome, including decreases in potentially inflammatory bacteria (Prevotella and Veillonella) and increases in health-associated genera (Neisseria) 2 7 —mirroring some of the shifts observed in the LCHF study with athletes."
For individuals following LCHF diets, these findings offer reassuring evidence that the cardiovascular benefits of nitrate-rich vegetables remain accessible even when the oral microbiome undergoes dietary-induced changes.
The intricate relationship between our diet, our oral microbiome, and our health continues to reveal surprising complexities. The recent discovery that LCHF diets alter oral bacterial communities without impairing their nitrate-reducing capacity provides a powerful testament to the resilience and adaptability of our internal ecosystems.
While dietary patterns will inevitably influence the microscopic worlds within us, essential biological functions appear remarkably well-preserved.
This research offers reassuring news for athletes and health enthusiasts following LCHF diets while highlighting the enduring value of including nitrate-rich vegetables in our eating patterns—regardless of our overall dietary approach.
As science continues to unravel the mysteries of the human microbiome, one lesson emerges clearly: our bodies possess an extraordinary capacity to maintain crucial functions even as we change the fuel we provide them. The vibrant community living within our mouths not only adapts to our dietary choices but preserves its ability to unlock the health benefits hidden within a simple glass of beetroot juice.