Text: Editors VU Magazine  |  Image: Own image  |  27 November 2023 

„My children call me 'Professor Spit'," he says with a laugh. "Well, they hardly know what an amazing fluid it is."

Saliva: Just an underappreciated fluid to your children?

„If only it were that simple. Saliva suffers from a poor image. People often find it disgusting. Hence, it's a well-kept secret that saliva holds a wealth of knowledge and potential applications. This extends beyond digestion and moistening mucous membranes and teeth. The importance of saliva is truly felt when one suffers from dry mouth."

What are some applications of saliva?

„A single drop of saliva can contain a billion bacteria, but they don't necessarily make us sick. It has a wealth of proteins that could serve as blueprints for medications. Think of new antibiotics or wound-healing ointments. Since we can chemically recreate many substances from saliva in our lab, research into these antimicrobial and wound-healing substances is very accessible."

Can studying saliva indicate someone's health?

„The absence of certain proteins can indicate difficulties in mouth moistening, higher susceptibility to inflammation, or chronic dry mouth."

„We're also researching the detection of substances indicating general health issues, like Sjögren's syndrome or intestinal diseases. This research is still in its early stages, primarily because current techniques for diagnosing such diseases rely on blood tests. More research is needed to establish a clear link between saliva substances and these diseases."

„However, the research is promising. Donating saliva is much easier than giving blood, as it doesn't require needles. I believe there will be more saliva tests in the future as a supplement to existing diagnostics. This is evident in drug tests, HIV tests, or COVID tests: all screening tests that highlight the potential of saliva diagnostics."

About dry mouth, is it a significant issue?

„When saliva production is inhibited, for example, during stress, pain, or negative emotions, one can experience dry mouth, which is unpleasant. The effects of a prolonged dry mouth are much more severe. Most patients with saliva deficiency in the Netherlands, over a million, suffer from chronic dry mouth, making processes like eating, swallowing, and speaking challenging. Additionally, the risk of cavities and gum inflammation increases due to the loss of saliva's protective function."

„Many elderly people experience dry mouth. As the population ages, I expect these symptoms to increase. Dry mouth care isn't part of regular care in most Dutch dental practices. Consequently, many issues go unnoticed. If it were up to me, dentists would routinely conduct saliva tests. A simple spit test to measure saliva production and asking about dry mouth experiences can help. If done at every check-up, the dentist can detect abnormalities and intervene."

Are there other tests being developed where saliva plays a central role?

„Saliva measurements are widely applicable. I'm currently working with TNO (Dutch Organisation for Applied Scientific Research) to develop a test for detecting nitrous oxide in saliva. Nitrous oxide is often misused for recreational purposes. Driving under its influence is dangerous and illegal. Ideally, such a saliva test could be administered roadside. This shows that saliva research extends beyond dentistry."