Intestinal
lipid transport plays a central role in fat homeostasis. Here we review the pathways regulating intestinal absorption and delivery of dietary and biliary
lipid substrates, principally long-chain
fatty acid,
cholesterol, and other
sterols. We discuss the regulation and functions of CD36 in
fatty acid absorption, NPC1L1 in
cholesterol absorption, as well as other
lipid transporters including FATP4 and SRB1. We discuss the pathways of intestinal
sterol efflux via ABCG5/G8 and ABCA1 as well as the role of the small intestine in
high-density lipoprotein (HDL) biogenesis and reverse
cholesterol transport. We review the pathways and genetic regulation of
chylomicron assembly, the role of dominant restriction points such as
microsomal triglyceride transfer protein and
apolipoprotein B, and the role of CD36, l-FABP, and other
proteins in formation of the prechylomicron complex. We will summarize current concepts of regulated
lipoprotein secretion (including HDL and
chylomicron pathways) and include lessons learned from families with genetic mutations in dominant pathways (i.e.,
abetalipoproteinemia,
chylomicron retention disease, and
familial hypobetalipoproteinemia). Finally, we will provide an integrative view of intestinal
lipid homeostasis through recent findings on the role of
lipid flux and
fatty acid signaling via diverse receptor pathways in regulating absorption and production of satiety factors.