Slower Fermentation Rate of Potato Starch Relative to High-amylose Cornstarch Contributes to the Higher Proportion of Cecal Butyrate in Rats

Abstract

This study aimed to examine the mechanism for differential effects of low- (LPPS) and high-phosphorus (HPPS) potato starches and high-amylose cornstarch (HACS) on rat cecal fermentation, the n-butyrate proportion in particular. In ileorectostomized rats, the in vivo resistant starch (RS) contents were determined to be 66% (LPPS), 66% (HPPS) and 36% (HACS), but the carbohydrate/nitrogen (C/N) ratios of the ileal digesta were comparable among the respective starch diets. In intact rats fed diets including similar amounts of RS, the cecal n-butyrate proportions in the LPPS- and HPPS-fed rats were equally higher than in the HACS-fed rats. The cecal starch contents were fivefold greater in the LPPS- and HPPS-fed rats than in the HACS-fed rats. The results suggest that potato starches and HACS are not equivalent n-butyrate producers in the rat cecum and that the slower fermentation rate of potato starches relative to HACS might be responsible for the higher n-butyrate proportion.

Effects of Raw Potato Starch with High Resistant Starch Levels on Cecal Fermentation Properties in Rats

“…Consumption of HAS and potato starch diets increased acetate and total-SCFA productions and lowered pH in rat cecum similar to previous studies (14,15). However, cecal propionate concentration was not different among the groups in the current study.…”

“…In the current study, the effect of raw potato stach on the intestinal fermentation properties in rats were examined. HAS and potato starch isolated from SD and KH contained high RS levels, and the cecal content weights in these groups were higher similar to previous studies (14,15). Further, it has been reported that starch with lower digestibility increases the amount of digesta in the distal gut, and a large volume of digesta is known to provide a favourable environment for microbial growth in the distal gut by providing nutrients to gut bacteria (3,20).…”

“…Potato, a major dietary source of starch is widely consumed as a staple food and its starch is being used as a raw material or additive in the processing industry. Raw potato starch is considerd to be a source of RS type 2 (9) and it is well known that its consumption promotes SCFA production and lowers pH in the colon (14,15). However, effect of potato starch consumption on stimulation of IgA secretion and toxic metabolites production is less well appreciated.…”

In Vivo Assessment of Resistant Starch Degradation by the Caecal Microbiota of Mice Using RNA-Based Stable Isotope Probing—A Proof-of-Principle Study

“…Notably, labeled metabolites for cross-feeding might have also resulted from starch hydrolysis mediated by the host itself in the small intestine through the enzymatic activity of pancreatic α-amylases, mucosal maltase-glucoamylases and sucrose-isomaltases [ 55 ]. However, starch fractions from potatoes were shown to be degraded rather slowly in comparison to other botanical sources in vitro and in vivo [ 56 , 57 ].…”

Effect of Calcium‐Fortified Potato Starch on Cecal Fermentation and Fat Accumulation in Rats

“…Raw potato starch (PS) is resistant to digestive enzymes and contains a higher RS content. [ 2 ] It has been suggested that the presence of high quality esterified phosphate groups in PS causes the inhibition of hydrolysis by α‐amylase. [ 3,4 ] Consumption of raw PS is reported to promote the production of SCFAs and lower the colonic pH through fermentation by colonic microbiota.…”