Butyrate impairs lipid transport by inhibiting microsomal triglyceride transfer protein in Caco-2 cells.

Recently, the idea was advanced that short-chain fatty acids (SCFA) may potentially regulate intestinal fat absorption. The aim of this investigation was to examine the effects of butyrate on the intracellular events governing the assembly of triglyceride-lipoproteins in enterocytes. To this end, differentiated human Caco-2 cells were exposed to 10 or 20 mmol/L butyrate for 20 h. The incubation of Caco-2 cells with butyrate decreased cholesteryl ester (P < 0.005) export in the basolateral medium, probably due to reduced activity of DL-3-hydroxy-3-methyl-glutaryl-CoA reductase (P < 0.02), the rate-limiting enzyme in cholesterol synthesis. Furthermore, a drop was noted in the protein expression of microsomal triglyceride transfer protein (P < 0.03), concomitant with the inhibition of de novo apolipoprotein B-48 synthesis (P < 0.02) and triglyceride-rich lipoprotein output (P < 0.03). Our results support the hypothesis that SCFA can influence lipoprotein concentrations by limiting lipid release from the small intestine into the circulation.