Potato and high-amylose maize starches are not equivalent producers of butyrate for the colonic mucosa

Portal appearance of short-chain fatty acids (SCFA) produced from fermentat ion of three different resistant starch (RS) sources (raw potato starch, hi gh-amylose maize starch and retrograded high-amylose maize starch) was inve stigated in pigs. The catheterization technique coupled with determination of portal blood flow was used to estimate SCFA uptake by the colonic mucosa . Our hypothesis was that these three RS were not equivalent butyrate provi ders for the colonic mucosa and that butyrate uptake would therefore be dif ferent after in vivo fermentation of each starch. The starches induced diff erent patterns of appearance of SCFA in the portal blood; raw potato starch was the only RS source to show a significant appearance of butyrate in the portal blood. Thus, uptake of butyrate by the colonic mucosa apparently di ffered between starches. This finding suggests that butyrate uptake does no t only depend on the flow of butyrate appearing in the lumen. Indeed, for u nexplained reasons, utilization of butyrate by the colonic mucosa appeared to be less efficient when the butyrate was produced from fermentation of po tato starch than when it was produced from fermentation of the other RS sou rces.