In June scientists at King’s College London announced a link between bacteria in the mouth and gut and the progression of cognitive decline in Parkinson’s disease. Photo / Getty Images
From flossing to probiotics, good dental hygiene is key to warding off conditions such as Parkinson’s.
I’m in a funky dental practice near London’s Bond St and Dr Victoria Sampson is encouraging me to spit into a test tube. I feel slightly ridiculous. What will my saliva contain? Gin? Coffee? Lipstick?
I’m here because the new buzzword in dentistry is the oral microbiome – a “dynamic eco system” of over 700 different species of bacteria, fungi, yeasts and viruses in the mouth, tongue, cheeks, teeth, gums.
It is the second largest and most diverse microbiome after the gut. Usually the good and bad bacteria are balanced, but when there are more bad bacteria present, problems occur. And Sampson has spent three years refining her own test for The Health Society, Oralis 1, to test the inner workings of the oral microbiome.
She’s the woman who can tell you if your breath smells – for your own good. Her test can reveal whether you have good or bad bacteria in your mouth, how acidic your saliva is, how much inflammation you have, and whether you have genetic mutations that could triple your risk of developing gum disease. Her mantra is: “You go to your doctor for a blood test, why not go to your dentist for a saliva test?”
But most importantly, this test may be a key to helping to ward off systemic diseases linked to poor oral health, such as diabetes, cardiovascular disease, Alzheimer’s and infertility.
In June, scientists at King’s College London announced a link between bacteria in the mouth and gut and the progression of cognitive decline in Parkinson’s disease, so all the more reason to have my oral microbiome tested.
Specific changes in these bacteria (the microbiome) are associated with cognitive decline in Parkinson’s, including a shift from mild memory issues to dementia, a common symptom.
According to Dr Saeed Shoaie, co-author of the study: “The human gut and oral bacterial communities are increasingly linked to neurodegenerative diseases.
“A common gum disease bacterium like Porphyromonas gingivalis, has been discovered as a potential driver of Alzheimer’s.”
So why am I here? For years I have battled the dreaded periodontal pockets, a symptom of periodontitis (gum disease), which if left untreated can lead to severe infection, loss of bone and gum, even tooth loss. I spend hours flossing madly, staying vigilant, if I find a sore area of gum.
When you have gum disease, tissue breakdown can occur, causing gaps. These pockets hold bacteria, causing damage to the surrounding tissues that anchor teeth within the jaw. If gums bleed, a periodontal pocket may have formed.
Periodontal disease is often hereditary. My mum has it; my grandmother was given dentures in her 20s. But gum issues get worse after the age of 40. I’ve had several pockets measuring over 7mm (advanced periodontitis). At the moment they’re stable, but my plaque levels worry my hygienist.
Porphyromonas gingivalis is a species of bacteria closely linked to advanced periodontal disease. I am nervous as to what my test will show but test I will. My one hope is I gave up free sugar for this paper back in February, so perhaps I will see a reduction in inflammation in my saliva and a lesser chance of serious disease?
Cosmetic dentist Dr Sandra García Martin uses Oralis 1 for her patients. “If I see chronic bad breath, recurring cavities, inflamed gums, oral thrush, those are signs of dysbiosis, the imbalance of the microbiome when pathogenic germs take hold. Maybe the patient has high levels of streptococcus bacteria (which cause strep throat). Okay, so then, let’s get you on this diet, or that toothpaste.”
Sampson designed her own test, worried previous ones were too superficial. “They weren’t pairing your genetic mutations and host immune response to the bacteria,” she recalls. “You’d have two patients with exactly the same microbiome test results, but one would have raging gum disease, the other would be completely fine.
“We started to realise it’s not the bacteria that causes the disease, but how your body responds to that bacteria, plus hereditary factors. So if you have genetic mutations, you might respond more aggressively.”
At her clinic The Health Society – the first oral diagnostic centre in Europe – she tests 500 bacteria in the mouth, looking at 10 genetic mutations. “We can assess not only the bacteria present in your microbiome but also understand your body’s individual response to that bacteria. At least 50 systemic diseases are now linked to the oral cavity.”
Patients with good oral hygiene can still develop gum disease if their body responds poorly to bacteria. Even super-healthy bio-hackers may find they have genetic mutations, “which means they’re predisposed to inflammation, so if they ever picked up a cigarette, they’re more likely to get gum disease than another person”.
She also sees people going through cancer treatment, or living with heart disease. “We get referrals from doctors, gastroenterologists.” The King’s College study underscores the potential importance of maintaining oral and gut health in mitigating or slowing neurodegenerative processes.
“As research into the microbiome and inflammation has exploded, these tests have become far more credible. It was definitely seen as fringe a few years ago – more biohacker than dental clinic. But they’re now used in preventive medicine, longevity clinics, and increasingly in mainstream dental care,” says Dr Parveen Dehal, associate dentist at London Smiling.
After I’ve finished spitting into a test tube, Dr Sampson takes an extensive medical history – age, weight, number of fillings, toothpaste/mouthwash used, whether I’ve had a root canal. Plus diet, medication, family history.
The sample is sent to the lab, where the DNA from the microorganisms from our saliva is extracted and processed. It’s run through a sequencing machine where the millions of DNA sequences are matched to a database of microbiome genomes to work out which microorganisms are present.
“We analyse the growth patterns of diverse bacterial groups, factor in your genetic mutations and compare your microbiome to those of ‘healthy’ individuals to generate an overall health risk score,” explains Sampson, who is in the process of building a biobank for oral microbiome samples to scientifically validate links between oral and systemic health.
She was shortlisted as one of the most promising young scientists in Europe for the Forbes 30 under 30 in Science and Healthcare for her work on salivary diagnostics.
The test examines 500 bacteria, focusing on the top 20 strongly associated with diseases, including gum disease, colorectal cancer and Alzheimer’s. Results come back in three to four weeks and she designs a treatment plan based on your unique biological makeup.
She calls it seeing dentistry through a different lens. “For example, we found is that if a patient is battling with diabetes, we can help lower their blood glucose levels more than them doing it alone with their doctor.
Or we have patients who have really high inflammatory markers, but brush and floss really well, so there could be a problem like a massive abscess that doctors missed. If you’re having radiotherapy, often your saliva glands may be shot and you suffer from a dry mouth (xerostomia). Or a patient may have been taking antibiotics which kill friendly bugs with the pathogens.”
It’s far better than I dared hope. I score 9.6 in terms of risk (normal is 10). Halitosis, gum disease, decay and general inflammation scores are low. Levels of pathogenic bacteria associated with oral disease are normal or absent.
I have low levels of bad bacteria, hurrah (and no concerning genetic mutations associated with Alzheimer’s and neurodegeneration). My main problem is I have low levels of good bacteria, too, so Sampson recommends taking a probiotic daily.
In her 20-page report, she explains that the two genetic mutations highlighted by my test are the DEFB1 gene – which makes you more addicted to sugar (oh yes), and the IL6 gene (a marker for inflammation). As my beta-defensin-1 production is reduced (which plays a key role in the innate immune system), I need vitamin-rich foods (blackcurrants, kiwi, berries, broccoli) and more vitamin D found in zinc (seafood, nuts) and selenium (tuna, cottage cheese).
To my amazement my gum disease is stable. As a comparison Sampson shows me the anonymous test result of a “healthy” man in his 40s who hasn’t been to a dentist in years. He has sky-high levels of bad bacteria including Porphyromonas gingivalis (where the more virulent strains can be a driver of Parkinson’s and Alzheimer’s).
“Porphyromonas gingivalis in some patients releases what we call gingipains. These gingipains are able to cross the blood-brain barrier and have been shown to cause neuroinflammation and damage to the neurons. In one study, over 97 per cent of patients with Alzheimer’s had gingipains in their cerebral spinal fluid.”
Clearly I owe a debt to my brilliant hygienist, but also taking the test has been the incentive I need. It’s easy to get dispirited about flossing, and slack off.
I feel genuinely hopeful about my gums for the first time in over a decade. I buy the probiotic she suggests but the game-changer is the Oral-B iO8 toothbrush she recommends.
With more targeted brushing (on my phone, it advises when to increase or decrease brush pressure) I’m down to just two minutes. My teeth and gums feel super-clean. I’d begun to fear I’d never have a relationship again because of the hours in the bathroom (and wall of toothbrushes!).
Around 50% of the population has some level of gum disease. We need to take the shame away. It may sound unconventional – a little “out there”, but the saliva test feels genuinely empowering especially if it acts as an early warning system about diseases like Parkinson’s and helps us future-proof our brains.
1. Have regular check-ups and professional dental cleaning
A hygienist will remove plaque and tartar from around teeth, reducing gum inflammation. “I prefer our patients to see their hygienist more than to see me,” says Dr Sampson.
2. Use a smart-pressure toothbrush
Brush at a 30-degree angle toward the gum margin, says Sampson who recommends a smart pressure sensor toothbrush for those of us who over-brush or have recession.
3. Floss daily – before brushing
This breaks up plaque biofilms between the teeth. Consider interdental brushes if you have larger pockets. “If you don’t have time to brush your teeth, please floss. At least the saliva protects us all the time,” says Martin.
4. Use a special toothpaste
Sampson recommends BioMin toothpaste which releases calcium, phosphate and fluoride over several hours after brushing. Or if you want fluoride-free, SuperTeeth Prebiotic Mineral Toothpaste, fortified with naturally derived hydroxyapatite, prebiotics and CoQ10 to reduce inflammation while inhibiting harmful bacteria growth.
5. Take oral probiotics or add more microbe-friendly foods to your diet
Ideally those which contain zinc, vitamin D, vitamin B12, calcium and vitamin C.
Fermented foods such as kefir, kimchi or sauerkraut also provide live, friendly microbes known as probiotics.
Increase intake of food rich in prebiotics: apples, onion, garlic, bananas, leeks, asparagus, wholegrain. Have a high-fibre diet and omega 3 fish oils.
6. Keep hydrated
If you regularly wake with a dry mouth, it is important to tackle hydrating it to reduce risk of further oral diseases. Sampson recommends a hydrating gel such as Oralieve and Xylimelts (discs that stick to gums and teeth to increase saliva flow) and to chew sugar-free gum. Sinusitis and allergies can signify an imbalance in the microbiome.
Stay hydrated – saliva is your body’s natural mouthwash, buffers acids and provides antimicrobial properties to control harmful bacteria. Do mouth exercises to stimulate saliva, says Martin. “Every two hours, do simple movements around the mouth with your tongue, to stimulate saliva ducts under the tongue.”
1. Spices, acids and alcohol
“Anything that causes inflammation,” says Dr Martin. Booze diminishes saliva and dries the mouth.
2. Sugar and ultra-processed foods
These feed the wrong bacteria. Eat a fibre-rich, plant-based diet to support both oral and gut health.
3. Stress
This impacts both immune function and microbial balance. If you’re sleeping well, you have less stress.
4. Cigarette smoke
This directly affects microbes through oxygen deprivation, or by disrupting defence mechanisms against pathogens. But vaping is much worse because it’s constantly in your mouth, says Dr Martin.
5. Too many soft foods
“Eat more solids, says Dr Martin. “ Our jaws are designed to eat hard things. Kids now eat fewer apples and more yogurt as a snack, but gums are designed to have hard food.”
6. Pollution
Inflammation and immune responses are triggered by air pollutants which can alter the mouth and nasal cavity environment, favouring the increase of pathogens.
7. Sedentary jobs
Another baddie for our microbes. Regular daily fitness is key.
8. Harsh antiseptics
Unless prescribed – these wipe out beneficial bacteria. “The best antiseptic is always salt water.”