The race to get a new nutraceutical product from discovery to market can cost a company millions of dollars in lost revenue for time spent in the development process. Clearly, the sooner a product hits the shelf, the sooner profits can be enjoyed. But a recent invention has now provided food, pharmaceutical, supplement and ingredient companies with a tool-a computer-controlled in vitro model of the human gastrointestinal tract-for understanding the nutritional impact of food functionality in the human gut.

TNO, the Netherlands Organization for Applied Scientific Research, has created a new technology for testing new ingredients, bioactives and finished foods-a computer-controlled model of the gastrointestinal tract of human adults, babies and the elderly. In vivo studies are expensive, time consuming and not always illuminating about the underlying mechanism or kinetics of active ingredients. The TNO gastrointestinal models can serve as a valuable precursor in the early phases of development of a nutraceutical product. Use of the models can help reduce the number of ingredients that need to be tested.

Simple static models have been available for testing products for many years, but are not truly representative of the changing variables inside the gut. Such simplistic models expose a compound to a mixture of electrolytes at a constant pH for a measured amount of time. However, the TNO models allow for the study of compounds in a manner similar to the in vivo situation as they would behave as they move through the GI tract; thus the TNO model supplies more accurate information about what takes place as compounds pass through the GI tract. Unlike static models, the TNO models can register even small differences in the kinetics between slightly different test compounds.

The TNO gastrointestinal models (TIM) simulate the successive dynamic conditions in the human gastrointestinal tract, such as fluctuating pH values, varying enzyme activity, gastric and intestinal mixing and transport by peristaltic movements, gastrointestinal secretions and the absorption of water and digested food. Several different models are available; for example, TIM 1 simulates the stomach and the small intestine (duodenum, jejunum and ileum), while TIM 2 simulates the large intestine or colon. TIM 2 contains a dense complex of anaerobic microflora and testing can be done to determine how functional foods interact with the microflora.

This new technology can be used to study a variety of factors, from functional food ingredients to the interplay of microorganisms to the interactions between foods, drugs and dietary supplements. Benefits of the TNO gastrointestinal models include:

• Accurate and reproducible results that limit the amount of test material needed and the number of test runs as compared to human and animal studies.
• Lower cost studies, averaging just a fraction of the cost of human and animal studies.
• Quick study results and shorter total development times. Study results are available in an average of three weeks and employing the model very early in the development process can significantly shorten total development time.
• An understanding of the underlying mechanism of digestion or bioavailability of components can be studied through the multiple sampling points along the digestive process; where and to what degree a compound is digested and the influence it has on the microflora can be determined in each phase of the digestive system
• No ethical limitations, thus providing time and cost savings through bypassing clearance by an ethics committee. This allows for quick testing for stability and safety of genetically modified organisms and crops

The TNO gastrointestinal models have been extensively validated for applications ranging from digestion of proteins and carbohydrates to absorption and bioavailability of nutrients from the different parts of the small intestine to survival and interaction of lactic acid bacteria and foodborne pathogens. Clients have also sent their own materials with properties that are well known so that they could verify the validation of the model themselves.

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About the author:
Mark Posno is a business development manager at TNO based at the Arthur D. Little facilities in Cambridge, MA. His main areas of interest include innovation of ingredients and products in relation to nutraceuticals, functional foods and convenience foods. TNO, the Netherlands Organization for Applied Scientific Research, is one of the largest contract research organizations in Europe and a strategic partner of Arthur D. Little in the area of life sciences.He can be reached at Arthur D. Little, Acorn Park, 15W/107, Cambridge, MA 02140; 617-498-5171; Fax: 617-498-7288; E-mail: posno.mark@adlittle.com.