The Promise and Challenges of Biobanking in Digestive Disease Research

Advances in biomedical research require the use of many different model systems in the laboratory, ranging from the simplest eukaryotes, yeast, to the most complex, humans. In general, basic biological mechanisms are most efficiently studied in simple model systems where the genetic background can be controlled and manipulated, and large numbers of organisms can be quickly characterized. Profound discoveries have been made in yeast (Saccharomyces cerevisiae), nematodes (Caenorhabditis elegans), fruit flies (Drosophila melanogaster), and zebrafish (Danio rerio). Mammalian models largely focus on the use of either in vitro tissue culture or rodent models such as mice. Under certain circumstances, studies in non-human primates are performed to study disease processes such as hepatitis C virus and Simian immunodeficiency virus, as well as evaluate pharmacologic interventions that parallel the biology in humans. Here, too, basic mechanisms of normal biology and disease can be probed in experiments under carefully controlled conditions. Nevertheless, it is the application of knowledge to human biology that counts the most. Despite compelling evidence for the functional mechanisms in these model systems, direct relevance to humans is sometimes difficult to predict. For example, the efficacy of pharmacologic agents clearly useful in rodent models may not translate into meaningful results in humans. Furthermore, deleterious side effects of pharmacologic agents in rodents may not be observed in humans. Finally, just because a model of disease in a mammalian system phenotypically seems to have similar characteristics of human disease does not mean that this model is relevant to human biology. Enormous expense, hard work, and effort may be expended studying these model systems later to find out that the relevance to humans is limited.