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 response to diet, it important to find and evaluate candidate genes, which have common functional variants in the general population, and which may be determinants 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 common variation in the coding sequence, which results in either alanine or threonine to be translated at residue 54. This amino acid variation has an in vitro functional impact. In addition, there have been several published associations 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 that most of the inter-individual variation in the plasma lipoprotein response to dietary fiber could be attributed to the FABP2 A54T polymorphism. However, it is likely that differences in environment, such as the type of fatty acid or fiber consumed, might interact with functional differences in the gene product to produce phenotypic differences.
CONCLUSIONS: This means that more experimental work, using a variety of study samples and complementary approaches, is necessary before advocating routine testing of FABP2 genotype in people in order to determine their potential responsiveness to various dietary interventions, such as increased dietary soluble fiber.