Spit: Worth Its Weight in Gold?

Besides helping with eating and speaking—even singing and whistling—saliva is key to good oral health. Now, Agricultural Research Service (ARS) scientists in Peoria, Ill., are examining the secretion's potential to open a biochemical window into the body's metabolism of sugars in food.

From such observations, ARS chemist Neil Price aims to create a baseline map of the body's constructive, or anabolic, activity during exercise, dieting or supplement-taking. Of particular interest is using the approach, called nutritional diagnostics, to enumerate populations of friendly gut bacteria, based on the body's handling of oligosaccharide sugars.

Derived from certain crops, these short-chain sugar molecules have potential use as prebiotic food ingredients that can nourish Bifidobacteria and other species whose colonic activity is tied to gastrointestinal health in humans and poultry.

According to Price, with the ARS National Center for Agricultural Utilization Research in Peoria, saliva is an ideal medium for charting sugar metabolism because key metabolites are turned over faster in saliva than in blood, and it's less intrusive to obtain. First, though, saliva's assorted proteins, lipids, hormones and other components must be identified, adds Price, in the center's Bioproducts & Biocatalysis Research Unit.

To that end, he is collaborating with scientists at the Scripps Research Institute in San Diego, Calif., and at the University of Rochester (UR) in New York. Their project—called salivary proteomics cataloging—dovetails with growing scientific interest in using saliva for applications ranging from illegal-drug-use detection to disease diagnosis, such as for dry mouth. This last one is an interest of ARS collaborator James Melvin, who directs UR's Center for Oral Biology.

Price's studies in Peoria include using mass-spectrometry analysis to measure the rate at which the body metabolizes simple sugars from food and parcels them out as building-block material for salivary components, especially into more complex lipids, sugars and glycoproteins.

Read more about the research in the May 2006 issue of Agricultural Research magazine.

ARS is the U.S. Department of Agriculture's chief scientific research agency.