saliva test from patient


Expect More From Your Spit: The Slobbery Link Between Your Saliva and Diabetes

Written By : Generations of Smiles Writers

Reviewed By : Charles Rodgers, DDS

Published: Apr 08, 2022

Updated: Oct 04, 2023

In This Article
When it comes to diagnosing a disease, you may have to look no further than the spit in your very own mouth. With current research exploring the use of oral DNA in saliva as a diagnostic tool for oral and systemic diseases, such as heart disease, gum disease, and diabetes, timely and less invasive testing will be more easily achieved, resulting in better health care, including oral health care. 
What is oral DNA testing? The use of saliva to diagnose disease in the mouth and body is also referred to as oral DNA testing because it uses specific information found in your saliva to shed light on what is happening in your body. 

Diabetes is not spread through saliva, but the fluid in the oral cavity can actually aid in diagnosing and monitoring diabetes so the harmful complications of this disease never fully develop. Researching the connection between saliva and diabetes through salivary diagnostics, or saliva tests for health issues, is opening up new and innovative ways to diagnose diseases, like periodontitis, in more accessible, less invasive methods. By using saliva instead of blood for testing, patients will be more likely to have the tests done so that disease or the potential for disease can be caught early and possibly be avoided altogether. Studies are being done to find a correlation between salivary and blood glucose levels as well as looking for biomarkers, objective signs indicating your medical state, for a plethora of diseases and conditions, including diabetes.

Diabetes is a disease that affects over 37 million people in the United States alone. According to the Center for Disease Control,  diabetic patients suffer from issues with the insulin released by the pancreas, resulting in an inability to transfer sugar in the blood, also called glucose, to the cells where it is needed. The glucose ends up staying in the bloodstream causing high blood sugar, which can lead to a long list of negative effects on the body, including loss of vision, heart disease, kidney disease as well as causing troubling gum disease and oral infections.
Currently, the way that glucose in the blood is monitored is by sticking the finger to produce a drop of blood. For patients, this is an unpleasant requirement for keeping tabs on their diabetes. For individuals who have an aversion to needles, having a sample of blood frequently taken can cause them to avoid testing their blood sugar, leaving them at risk of the harmful effects of unmonitored diabetes. With recent research suggesting a strong link between the glucose levels in saliva and in blood, an easier testing process with no pain is possible and greatly anticipated by doctors and patients alike.  

What Is Salivary Glucose?

Saliva, or spit, is the unique substance found in your mouth that serves many jobs like delivering important minerals to the teeth, washing away food debris, and helping to break down food in the mouth for taste and ease of swallowing. Saliva is created in three large pairs of saliva glands in addition to hundreds of smaller glands in the oral cavity. 

Can diabetes cause salivary gland problems? Saliva is crucial to the health of the mouth by providing antibodies that attack and kill germs. Patients can be diagnosed with salivary gland disorders and even cancer. But low levels of saliva can also be connected to diseases, such as diabetes, that can then result in further complications like gum disease

Does saliva contain sugar? Glucose is the sugar that comes from the foods you eat and provides energy for all your bodily functions. Glucose can be found in the blood, which is the main transportation system of these energy-source sugars, but it can also be in saliva. 
Salivary glucose is the sugar found in saliva. It can be simply tested with a swab of the mouth, unlike blood glucose which requires a small puncture of the finger in order to draw blood to be tested for sugar levels. In recent studies, salivary glucose levels in diabetes are much higher than in patients who are not diabetic, which is also the case with blood glucose levels in diabetic patients. This shows the correlation between salivary and blood glucose levels which may lead to more saliva tests and a lighter dependence on blood testing. 

How Can Salivary Diagnostics be a Preventative Care for Other Diseases?

Living with a disease such as diabetes can be life-altering. If symptoms are kept at bay, the need for testing and regular checkups that are crucial in keeping the disease under control must continue regardless of how you feel. With the strong potential of salivary diagnostics used to test for multiple conditions, diseases in their early stages can be found, and steps can be taken to reverse the trajectory of the disease so that patients can remain healthy before the disease takes hold and does irreversible damage. A good example of this is in gum disease. Diagnosing gum disease by a dentist with a saliva test can pinpoint the actual bacteria strain so that the right treatment is taken.

What Can Salivary Diagnostics Detect?

Can saliva be used to detect diabetes? According to the American Dental Association, researchers are finding promising data that suggests that salivary diagnostics can be used to detect many different oral and non-oral diseases in the body, such as:
While your dentist usually diagnoses gum disease, such as periodontitis, through a visual examination or a dental saliva test, broader salivary diagnostics could open the door for dentists to diagnose many other diseases that affect the body as a whole. 

How Diabetes can present itself in your saliva

Does diabetes affect saliva?
 Studies have been conducted to see how strong the connection between glucose levels in saliva are compared with the amount of glucose in the blood. With these new studies, research continues to find evidence of significantly higher levels of glucose and lower rates of saliva flow in diabetic patients than in healthy patients. This promising research is paving the way for salivary diagnostics which are much more preferable than the more invasive blood testing that is currently the norm.

Can diabetes cause excess saliva? Diabetes can affect the amount of saliva produced and many diabetic patients complain of dry mouth, which is a side effect of the disease. While the salivary glands are working overtime in diabetic patients, the amount of saliva created in the mouth is notably lower than in similar aged, healthy control patients. Diabetic saliva also has higher levels of calcium and significantly lower levels of magnesium and zinc, which gives reason for diabetes, affecting healing time and oral infections, according to the National Institutes of Health. 
What is diabetic tongue? There is also evidence that a visual examination of the tongue can help to diagnose diabetes. Diabetic tongue refers to the similar physical characteristics of the tongue's appearance based on color, shape, fur color and thickness, and the amount of saliva flow in diabetic patients. Salivary gland dysfunction can also attribute to a positive diagnosis. 

How Your Dentist can Diagnose Diabetes

As research becomes more conclusive and when procedures and standards are established to make testing results more reliable, it is possible in the future that your dentist will be able to test and even diagnose diabetes using saliva glucose levels and other identified biomarkers. 

Can Salivary Testing Now Help Save You Money in the Long Run?

Because of the ease with which salivary testing can be done and with dentists and doctors being able to conduct salivary diagnostic tests, diabetic complications can be avoided because of early detection. If you have been diagnosed with diabetes, keeping a close eye on blood sugar levels as well as blood pressure and cholesterol can prevent diabetes from turning into kidney, eye, and nerve diseases that can be costly to treat and greatly diminish your quality of life. 
Early testing means avoiding treatment for complications caused by diabetes. With $1 in $4 of health care costs in the United States being spent on diabetic care, making it the most expensive chronic disease, the amount of money saved through more regular, less invasive salivary testing will be extremely significant.

Dental Medical Integration with Salivary Diagnostics

With salivary diagnostic research pioneers, like David T.W. Wong, D.M.D., D.M.SC., reimagining the role of dentists in medical intervention of diseases and cancers, patient care will increase and diagnosis of medical conditions will be easier, more accessible, and more widespread because of the integration of the dental and medical community efforts. 

Ask your Dentist for a salivary test

Salivary diagnostics can help your dentist diagnose or rule out diabetes. Making your trusted local dentist aware that you are interested in a saliva test can help you get the care you need to keep your body and mouth healthy. If you need a dentist, Smile Generation has a Find A Dentist tool to help you find an experienced dentist in your community.


Find your trusted, local dentist today!



"A Snapshot: Diabetes in the United States." CDC, 18 Feb. 2020,

"Cost Effectiveness of Diabetes Intervention." CDC, 7 Mar. 2022,

Gupta, Shreya, Meghan and T Nayak, JD Sunitha, Geetanshu Dawar, Hidhi Sinha, and Heelakshi Singh Rallan. "Correlation of Salivary Glucose Level With Blood Glucose Level in Diabetes Mellitus." Sep, 2017,,in%20early%20diagnosis%20for%20DM

Mata, Antonio D., Duarte Marques, Sara Rocha, Helena Francisco, Carolina Santos, Maria F. Mequita, and Jaipaul Singh. 2004, "Effects of Diabetes Mellitus on Salivary Secretions and its Composition in The Human."

"Oral DNA: Saliva Testing for Periodontal Disease." Charles Schof DDS, 2 Apr. 2022,

Pacific Dental Services, 2 Apr. 2022,

"Saliva." Mouth Healthy, 31 Mar. 2022,

Smile Generation blog articles are reviewed by a licensed dental professional before publishing. However, we present this information for educational purposes only with the intent to promote readers’ understanding of oral health and oral healthcare treatment options and technology. We do not intend for our blog content to substitute for professional dental care and clinical advice, diagnosis, or treatment planning provided by a licensed dental professional. Smile Generation always recommends seeking the advice of a dentist, physician, or other licensed healthcare professional for a dental or medical condition or treatment. 

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