A review of intestinal fatty acid binding protein gene variation and the plasma lipoprotein response to dietary components

Objectives: Because there is interindividual Variation in the metabolic res ponse to diet, it important to find and evaluate candidate genes, which hav e common functional variants in the general population, and which may be de terminants of interindividual differences in the response to components of the diet, such as dietary fat and fiber. One such candidate gene is FABP2, which encodes the intestinal fatty acid binding protein. This gene has a co mmon variation in the coding sequence, which results in either alanine or t hreonine to be translated at residue 54. This amino acid variation has an i n vitro functional impact. In addition, there have been several published a ssociations with metabolic phenotypes, such as impaired glucose tolerance, obesity, altered plasma lipids and lipoproteins. Results: It is the FABP2 T54 Variant that is almost always associated with the more deleterious phenotypic expression. Recent experiments have found t hat most of the inter-individual Variation in the plasma lipoprotein respon se to dietary fiber could be attributed to the FABP2 A54T polymorphism. How ever, it is likely that differences in environment, such as the type of fat ty acid or fiber consumed, might interact with functional differences in th e gene product to produce phenotypic differences. Conclusions: This means that more experimental work, using a Variety of stu dy samples and complementary approaches, is necessary before advocating rou tine testing of FABP2 genotype in people in order to determine their potent ial responsiveness to various dietary interventions, such as increased diet ary soluble fiber. (C) 1998 The Canadian Society of Clinical Chemists.