Methods and kits for diagnosing a pancreatic-based fat malabsorption disorder

1. A method of diagnosing pancreatic-based fat malabsorption disorder in a mammal comprising the steps of:

a) obtaining a baseline sample of blood from said mammal;

b) administering to said mammal a digestible composition comprising a free fatty acid which can be absorbed from the small intestine of the mammal in the absence of pancreatic lipase hydrolysis thereof and a triglyceride which cannot be absorbed from the small intestine of the mammal in the absence of pancreatic lipase hydrolysis thereof;

c) obtaining at least one subsequent sample of blood from said mammal following administration of said digestible composition;

d) assaying said baseline sample and said at least one subsequent sample for said free fatty acid and the fatty acids of said triglyceride;

e) determining from step d) the rate of fatty acid absorption of each of said free fatty acid and the fatty acids of said triglyceride in said mammal thereby obtaining a first absorption profile; and

f) comparing the first absorption profile with a second profile of fatty acid absorption obtained after carrying out steps a), b) and c) on a control mammal being positive or negative for a pancreatic-based fat malabsorption disorder, whereby the presence of a pancreatic-based fat malabsorption disorder in said mammal is indicated when said first absorption profile is comparable to said second absorption profile obtained from a control mammal being positive for said pancreatic-based fat malabsorption and the absence of a pancreatic-based fat malabsorption disorder in said mammal is indicated when said first absorption profile is comparable to said second absorption profile obtained from a control mammal being negative for said pancreatic-based fat malabsorption disorder;

wherein both said free fatty acid and said triglyceride are not radiolabeled; and

wherein said free fatty acid has an odd number of carbons and said triglyceride comprises fatty acids having an odd number of carbons.

2. The method of claim 1 wherein both said free fatty acid and said triglyceride are detectably labelled.

3. The method of claim 1 , wherein said mammal is a human.

4. The method of claim 1 , wherein said positive control mammal has a pancreatic-based fat malabsorption disorder which is the result of a deficiency in pancreatic lipase.

5. The method of claim 1 , wherein said disease associated with fat malabsorption disorder is selected from the group consisting of cystic fibrosis, hereditary pancreatitis, α1 anti-trypsin deficiency, Shwachman Syndrome, Johanson-Blizzard Syndrome, sideroblastic anemia, pancreatic insufficiency, lipase deficiency, co-lipase deficiency in children, both partial and complete pancreatic surgical resection, pancreatic cancer, chronic and autoimmune pancreatitis, hyperlipidemia, and hyperparathyroidism.

6. The method of claim 1 , wherein said free fatty acid is a saturated, long-chain free fatty acid and said triglyceride comprises one or more saturated, long-chain fatty acids.

7. The method of claim 6 , wherein said saturated long-chain free fatty acid is pentadecanoic acid (PA) and said triglyceride is triheptadecanoin (THA).

8. The method of claim 6 , wherein the free fatty acids resulting from the digestion and/or absorption of said substrates are PA and heptadecanoic acid (HA).

9. The method of claim 1 , wherein said assaying in step d) comprises using a quantitative gas-liquid chromatography method.

10. The method of claim 1 , wherein said rates of absorption are used to calculate one or more coefficients of fat absorption (CFAs).

11. The method of claim 10 , wherein one or more of said CFAs is used to diagnose a fat malabsorption disorder in said mammal.

12. A kit for diagnosing a pancreatic-based fat malabsorption disorder in a mammal, said kit comprising

a) an instructional material;

b) a digestible composition consists of a first fatty acid-containing substrate which can be absorbed from the small intestine of the mammal in the absence of pancreatic lipase hydrolysis thereof and a second fatty acid-containing substrate which cannot be absorbed from the small intestine of the mammal in the absence of pancreatic lipase hydrolysis thereof, wherein said first fatty acid-containing substrate is selected from the group consisting of pentadecanoic acid (PA) and heptadecanoin (HA) and said second fatty acid-containing substrate is selected from the group consisting of tripentadecanoic acid (TPA) and triheptadecanoin (THA); and

c) a tube or vial for obtaining a sample of blood from said mammal.

13. A method as claimed in claim 1 , wherein said pancreatic-based fat malabsorption disorder is pharmaceutically induced.

14. A method as claimed in claim 13 , wherein said disorder is induced by administration of orlistat to said control mammal.

15. A method as claimed in claim 1 , optionally further comprising assessing said mammal's stool for the levels of said free fatty acid and said triglyceride.