Exhale - and discover diseases

Volatile molecules may characterize diseases such as tooth decay and gum disease

Dental examination. Image: depositphotos.com
Dental examination. Image: depositphotos.com

The microbiome - the trillions of microorganisms (such as bacteria) that live in our bodies - has a decisive effect on our health. Some can cause serious diseases and some can fight them. Many studies have proven this over and over since 2007, when researchers announced the Human Microbiome Project. Until recently, it was believed that the gut microbiome - which has the largest population of microorganisms - is the main factor that affects the body's systems and the development of diseases. But today it is understood that the oral microbiome (in the oral cavity) also plays a central role in this and that its importance is similar to that of the intestinal microbiome.

Prof. Yael Khoury-Hadad, dentist and director of the Department of Oral Rehabilitation at the Faculty of Dentistry of the Hebrew University of Jerusalem, and Hadassah Hospital, investigates how the microbiome in the oral cavity affects the development of oral diseases - such as tooth decay, periodontal disease (inflammation around the teeth) and peri-implantitis (inflammation around the implants) - and the connection between these diseases and general, systemic diseases. "The relationship between the health of the oral cavity and the health of the body's systems has already been proven," she says. "Any injury or bleeding in the oral cavity (for example in the gums), even from brushing the teeth, may allow bacteria, even pathogenic (causing diseases), to reach the bloodstream from there. Therefore, a person who suffers from infectious (inflammatory) diseases in the oral cavity may suffer more from chronic diseases (eg heart disease, diabetes and Alzheimer's). Because it is known that at the base of these diseases there is an inflammatory mechanism, and inflammation in the mouth may make them worse."

In one of their latest studies, Prof. Khoury-Haddad and her team, which includes dentist Dr. Maisa Haik, decided to examine the relationship between the composition of bacteria in the oral cavity and volatile molecules (gases that are exhaled in the breath). Says Prof. Khoury-Hadad: "If a person suffers from an inflammatory disease in the mouth, the molecules he exhales will contain components derived from the contaminating bacteria and the products of the associated inflammation. Thus, these molecules can be a 'fingerprint' of oral diseases, and with them we can diagnose them at an early stage."

As part of the study, the researchers let 90 patients - 30 healthy, 30 with caries and 30 with gum disease - blow into two air bags; One bag was tested with an electronic nose - a device the size of a laptop computer developed by Prof. Hussam Hayek of the Technion, which contains a tube that is blown into and nano-sensors, each of which binds to certain organic compounds. The second air bag was tested with a gas chromatography (mass spectrometry) device, which separates volatile molecules, identifies and quantifies them. In both tests, the researchers discovered that each group of patients is characterized by other volatile molecules, and that there are molecules that characterize the patients only.

Following these results, the researchers decided to conduct a larger study, which is taking place these days, with the support of the National Science Foundation. In this framework, the volatile molecules of 300 patients whose medical condition is unknown will be tested with a device called Snipon, which was also developed by Prof. Hussam Haik. Prof. Khoury-Hadad says that this is an artificial intelligence device the size of a smartphone. "You can teach him to identify volatile molecules, characterize them according to different oral diseases and quantify them. The goal is for every person to be able to use it routinely or periodically, at home or in the clinic - to blow into it and know (for example, using a certain color that is obtained after exhaling) if there has been a change in the condition of their mouth. That is, it should be an accessible and easy-to-use tool that will contribute to the early diagnosis of oral diseases, including oral cancer."

צוות המחקר של פרופ' יעל חורי-חדד במעבדה

Life itself:

Prof. Yael Khoury-Hadad, 52 years old, married with four children (ages 16 to 25) and lives in Modi'in. She was born in Tunisia and immigrated to Israel at the age of 14. "I grew up in a small village with a well, carts and horses," she recalls, "and it was always clear to me that I wanted to take care of people." In her free time, she prefers to spend time in the kitchen, among the pots ("If I wasn't a doctor, I would be a cook. Cooking is therapy for me and I really like cooking for others. Their enjoyment of food gives me great satisfaction").

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