Jon A. Story, Ph.D. Professor and Associate Dean of the Graduate School Foods and Nutrition
Purdue University G1-C Stone Hall 700 W. State Street West Lafayette, IN 47907-2059 Phone: (765)494-6843 or (765)496-7352 Fax: (765)494-0906 Email: jastory@purdue.edu
M.S. in Zoology (Physiology) at Iowa State University in 1970
Ph.D. in Zoology (Physiology) at Iowa State University in 1972
AWARDS AND HONORS
1988
Mary L. Matthews Undergraduate Teaching Award
School of Consumer and Family Sciences
1988
Wellcome Visiting Professorship, North Dakota State University
FASEB
1990
Award of Merit in Research
Gamma Sigma Delta
DISCOVERY
Diet has long been implicated as regulator of sterol metabolism and, as such, as a means of altering risk in humans for development of diseases related to sterol balance. In the case of cholesterol, control of levels of cholesterol in the blood has been suggested as a means of reducing risk for cardiovascular disease while modification of bile acid excretion as been related to risk for colon cancer. Regulation of cholesterol balance is a combination of regulation of synthesis of cholesterol and the regulation of synthesis of bile acids, the predominant mode of excretion of sterol from the body.
Our interest has focused on the dietary regulation of bile acid metabolism. The balance among the amount of bile acids synthesized, the amount reabsorbed from the small intestine or excreted, and the relative amounts of the various bile acids making up the pool plays a pivotal role in regulation of cholesterol balance. We have focused on the effects of dietary fiber on these determining factors in cholesterol balance. Some sources of dietary fiber reduce bile acid reabsorption (and thus increase excretion) by "binding" bile acids and as a result of the increased viscosity of intestinal contents. These changes not only alter sterol balance directly as a result of the increased excretion but also alter the relative amounts of bile acids returning to the liver by altering the balance of passive and active routes of absorption. We have observed increased levels of mRNA for apical sodium dependent bile acid transporter (the active route of bile acid reabsorption) in the ileum of rats fed viscous sources of dietary fiber. This change is suggested to be responsible for the changes in the hydrophobicity of bile also observed in response to these sources of dietary fiber. Hydrophobicity of bile has been shown to be a regulator of cholesterol synthesis and bile acid synthesis, supported in our experiments by our observation of increased levels of mRNA for the rate limiting steps for these two processes (HMG CoA reductase and cholesterol 7alpha-hydroxylase, respectively). Similar changes in bile acid metabolism have been observed in humans in response to sources of dietary fiber which reduce hypercholesterolemia.
We have extended these efforts to an examination of the role played by diet in modification of colonic microflora, in addition to bile acids, and the effect these changes have in modifying risk for colon cancer. In this case we are focused on a much broader array of diet components as modifiers of bile acid metabolism.
Discovery Publications (selected)
Story, J.A. and J.G. Morris Jr. Diet induced changes in the colonic environment and colorectal cancer. J. Nutr. 134 (suppl.):459-486, 2004.
Spiller, G.A., J.A. Story, E.J. Furumoto, J.C. Chezem and M. Spiller. Effect of tartaric acid and dietary fiber from sun-dried raisins on colonic function, bile acids, and volatile fatty acids excretion in healthy adults. Br. J. Nutr. 90:803-807, 2003.
Spiller, G.A., Story, J.A., Lodics, T.A., Pollack, M., Monyan, S., Butterfield, G., Spiller, M. Effect of sun-dried raisins on bile acid excretion, intestinal transit time, and fecal weight: a dose-response study. J. Med. Food 6:87-91, 2003.
Jenkins, D.J.A., C.W. Kendall, D.G. Popovich, E. Vidgen, C.C. Mehling, V. Vuksan, T.P. Ransom, A.V. Rao, R. Rosenberg-Zand, N. Tariq, P. Corey, P.J. Jones, M. Raeini, J.A. Story, E.J. Furumoto, D.R. Illingworth, A.S. Pappu, P.W. Connelly. Effect of a very-high-fiber vegetable, fruit, and nut diet on serum lipids and colonic function. Metabolism 50:494-503, 2001.
Buhman, K.K., E.J. Furumoto, S.S. Donkin and J.A. Story. Dietary psyllium increases expression of ileal apical sodium dependent bile acid transporter mRNA coordinately with dose response changes in bile acid metabolism in rats. J. Nutr. 130:2137-2142, 2000.
Books, Chapters, and Monographs Publications
Story, J. A. and Morris, J. G. Jr. Diet Induced Changes in the Colonic Environment and Colorectal Cancer. Journal of Nutrition 134 (supplement):459-486, 2004.
Story, J.A. New insights into deitary fibre. Canadian Journal of Dietetic Practice and Research 64(4), 2003.
LEARNING
Courses
Fundamentals of Nutrition (F&N 315) - Basic principles of nutrition and their application in meeting nutritional needs during the life cycle.
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Contact Information
Foods and Nutrition Purdue University 700 W. State Street West Lafayette, IN 47907-2059
