Scientists from USDA's Agricultural Research Service (ARS) are in the process of cataloging the thousands of proteins, lipids, sugars and other substances that comprise human saliva. As reported by Jan Suszkiw, public affairs specialist, ARS, Beltsville, MD, in the May 2006 issue of Agricultural Research, researchers from ARS--in collaboration with scientists from the University of Rochester, Rochester, NY, and the Scripps Research Institute, La Jolla, CA--are studying how saliva might serve as a biochemical window into how the body assembles the nutrients in food into larger molecules for growth in the body.
For the purposes of this study, saliva is a better analytical medium than blood. "Saliva is a really good diagnostic medium, because it's noninvasive and has a fast turnover; you're making salivary proteins all the time," says Neil Price, research chemist, National Center for Agricultural Utilization Research, Peoria, IL.
The first step, as Suszkiw's article so succinctly states, is to get volunteers to "spit in the name of science." The researchers are particularly interested in using mass-spectrometry analysis to measure metabolism rates for fructose, glucose and other simple sugars in foods, and how the body then separates these sugars into building blocks for salivary components like mucins and other glycoproteins. This analytical approach, known as "nutritional diagnostics," could help researchers evaluate how an individual's metabolism responds to a particular food. Presumably, people would fall into given groups based on similar metabolism rates. Then, product designers could adjust foods accordingly to improve health.
"We aim to develop a model for how metabolism changes in response to exercise, dieting or dietary supplements," says Price. "If we know what happens in a healthy individual, and how that can change, then we might be able to explain what it means to 'feel healthy' in a measurable way."
The data collected could also help researchers assess health changes instigated by prebiotics, the symbiotic bacterial counterpart of probiotics. Price and his colleagues hope to count populations of good microbes in saliva based on the metabolism of oligosaccharides--simple sugars linked to beneficial bacterial growth and activity in the colon.
"We hope this will lead to improved food products for human health and, ultimately, create new markets for agriculture-based carbohydrates," says Price.
