There is an upsurge of interest in rationally designing foods to optimize their digestive fate, health benefits and ensure meeting individual nutritional needs. To this end, in vitro digestion methods offer opportunities to reconstruct various aspects of the human gastrointestinal tract and enable versatile, high throughput mechanistic studies of the physicochemical basis of digestion of food and food delivery systems1. However, limited studies have used this approach and tools to study the digestive fate of food hydrocolloids in infants and more particularly in the elderly. This work will provide an overview on how in vitro digestion models can be applied to compare the digestive fate of milk proteins and emulsions in infants, adults and the elderly.
The first part will focus on a comparative study of the behavior of lactoferrin, beta-lactoglobulin and emulsions stabilized by those proteins during dynamic in vitro gastric digestion replicating adult and infant digestion2. SDS-PAGE of digesta as well as laser based droplet sizing and fluorescence microscopy highlight the different digestive fates of the hydrocolloids between adults and infants. The second part will focus on the development of a gastro-duodenal model based on computer-controlled bioreactors mimicking the physiological conditions of the upper gastro-intestinal system of the elderly (Age>70years) and the post-prandial changes in luminal composition. The application of this novel model to study protein digestion will be exemplified.
Although human trials are essential for the development of functional foods, in vitro methods offer to put such efforts on a solid scientific basis. Unlike various pharmacological apparatus and pH-stat biochemical assays, the dynamic systems described will show how computer controlled bioreactors can be implemented to mimic physiological gastric and duodenal fluids flow, enzymatic levels and pH gradients according to consumer age.
Principle investigator: Prof. Uri Lesmes lesmesu@tx.technion.ac.il
1. Benshitrit, R. C.; Levi, C. S.; Tal, S. L., et al., Food and Function, 2012, 3, 10-21.
2. Shani-Levi, C.; Levi-Tal, S.; Lesmes, U., Food Hydrocolloids, 2013, 32, (2), 349-357.
