Influences of dietary adaptation and source of resistant starch on short-chain fatty acids in the hindgut of rats

Abstract

The effect of adaptation time on the concentration and pattern of short-chain fatty acids (SCFA) formed in the hindgut of rats given resistant starch (RS) in the form of raw potato starch (RPS) or high-amylose maize starch (HAS) was evaluated. Each starchy material was tested in diets containing 100 g indigestible carbohydrates/kg DM, and fed for 13, 28 and 42 d. At the end of each period, the content of SCFA was determined in caecum, distal colon and faeces. The caecal concentration of total and individual SCFA increased for both diets with increasing adaptation time. The concentration of butyric acid was higher in the group fed RPS than in that fed HAS at all adaptation times. The caecal proportion of butyric acid was low both in rats fed RPS and HAS (6 and 4 %, respectively) following 13 d of adaptation. However, after 28 d of adaptation, the proportion of butyric acid had increased to 19 % in rats given RPS. A longer adaptation period (42 d) did not increase the proportion of butyric acid further. With HAS, there was also a significant (P,0·01) increase in the proportion of butyric acid with longer adaptation time. However, the increase was much slower and the proportion of butyric acid reached 6 and 8 % after 28 and 42 d respectively. It is concluded that the pattern of SCFA formed from RS in rats is dependent on adaptation time. It cannot be excluded that the different patterns of SCFA reported in the literature for RS may be due to the time of adaptation.

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

“…Our preliminary study produced results consistent with the previous studies [6, 8] in which the molar proportion of butyrate in the total SCFA was significantly higher in a PS-fed group than in a HACS-fed group at the same dietary levels of the respective starches. There are a wide variety of PS sources that differ in their characteristics, including granule structure and amylopectin and phosphorus contents [26].…”

“…RS is defined as the sum of starch and degradation products of starch that reach the large intestine [5]. Previous studies with rat experiments showed that both of raw potato starch (PS) and high-amylose cornstarch (HACS) had a major impact on the cecal production of butyrate [6, 7, 8]. At the same time, however, these studies consistently reported that PS unlike HACS enhanced the molar proportion of butyrate in the total SCFA even when the adaptation period of PS ingestion and dietary dosage of PS differed.…”

Dietary supplementation with β-glucan enriched oat bran increases faecal concentration of carboxylic acids in healthy subjects

“…Different types of indigestible carbohydrates give rise to different amounts and patterns of CAs during colonic fermentation, and it may therefore be possible to regulate the CA formation by diet. The CAs formed may depend on for example the monomeric composition of the carbohydrates, the type of linkages between the carbohydrate monomers, their solubility and their molecular weight (Berggren et al, 1993;Casterline et al, 1997;Bird et al, 2000;Karppinen et al, 2000;Henningsson et al, 2002Henningsson et al, , 2003Nilsson and Nyman, 2005). Studies examining CA formation have mainly been conducted in vitro by using human faecal inocula, or in vivo using animal models.…”

“…Studies examining CA formation have mainly been conducted in vitro by using human faecal inocula, or in vivo using animal models. The rat is the most common model when studying the CA formation in vivo, although there are also some studies available in pigs (Berggren et al, 1993;Roland et al, 1995;Brown et al, 1997;Djouzi and Andrieux, 1997;Bird et al, 2000;Henningsson et al, 2002Henningsson et al, , 2003Nilsson and Nyman, 2005). Studies in man have mainly been performed by measurements of CAs in faeces and have been questioned on the premises that such measurements do not give information regarding the formation of CAs in proximal colon where most of the fermentation actually takes place.…”

In vitro availability of starch in heat‐treated potatoes as related to genotype, weight and storage time

“…For example, a significantly higher proportion of butyric acid was found in caecum of rats fed RS in the form of raw potato starch (19% of total SCFA) than in those fed high amylose maize starch (8%). 18 Le Blay et al 19 found that butyrate production throughout the rat caeco-colonic tract was promoted by long-term ingestion of a diet supplemented with resistant potato starch. This suggests that RS in potato products may be particularly prone to elevate colonic levels of butyric acid, and may thus be of special interest in relation to colonic health.…”