Heat moisture treatment of high amylose cornstarch increases its resistant starch content but not its physiologic effects in rats

Body Weight Development in Adult Dogs Fed a High Level Resistant Starch Diet

This study investigated the effect of Dodamssal rice, which has a high content of resistant starch, on obesity and hematologic properties in dogs. In Experiment 1, 24 spayed dogs were divided into three feeding groups: normal-fat basal diet (control), high-fat diet with 12% normal amylose type rice (hNAR), and high-fat diet with 12% high amylose type rice (Dodamssal rice; hHAR). In Experiment 2, 8 spayed dogs were assigned to a normal amylose type rice (NAR) group and a high amylose type rice group (HAR) with a normal-fat basal diet. After 24 weeks, an increase in weight and blood cholesterol was observed in both high-fat diet groups for Experiment 1. Specifically, an increase in serum alanine aminotransferase was observed over time in the hNAR group compared with that of the control; however, no such patterns were present in the hHAR group. Further, a significant weight-loss effect was observed in the HAR group in Experiment 2 at 4 weeks. The effect on body weight was due to the reduced digestibility of amylose and thereby lower dietary ME content. Overall, this confirmed that Dodamssal rice had a positive effect on weight loss in dogs, and these results suggest that Dodamssal rice has potential value as a raw ingredient for preventing obesity in dogs.

Therapeutic and Prebiotic Effects of Five Different Native Starches on Dextran Sulfate Sodium-Induced Mice Model of Colonic Colitis

SCOPE

The availability of studies related to the effects of natural macronutrients on inflammatory bowel disease (IBD) remain relatively limited. This study investigates whether and to what extent the consumption of five different native starches alleviate the clinical symptoms and dysbiosis of gut microbiota associated with colitis.

METHODS AND RESULTS

Using dextran sodium sulfate (DSS)-induced mouse model of colitis, the potential effects of native potato starch (PS), pea starch (PEAS), corn starch (CS), Chinese yam starch (CYS), and red sorghum starch (RSS) on the clinical manifestations and dysbiosis of gut microbiota are studied. Compared to CS and RSS, the consumption of PEAS, PS, and CYS significantly diminishes clinical enteritis symptoms, including reduced disease activity index, and the alleviated degree of colonic histological damage. Furthermore, the analysis of gut microbiota reveals the significant prebiotic characteristics of PEAS, PS and CYS, as indicated by the maintenance of gut microbiota hemostasis and the inhibition of typically pathogenic bacteria, including Escherichia coli and Helicobacter hepaticus.

CONCLUSION

Starches from potato, pea, and Chinese yam alleviate colitis symptoms in a mouse model, and also show significant prebiotic characteristics. These findings suggest a cost-effective and convenient dietary strategy for the management of IBD.

Rice Cakes Containing Dietary Fiber Supplemented with or without Artemisia Annua and Gynura Procumbens Merr. Alleviated the Risk Factors of Metabolic Syndrome

We investigated whether the consumption of Korean rice cakes enriched with dietary fiber with or without polyphenol rich plants might decrease the risk factors of metabolic syndrome (MetS). Rice cakes were manufactured using fructooligosaccharides, resistant starch, and psyllium as sources of dietary fibers with and without polyphenol rich Artemisia annua and Gynura procumbens Merr. (RC+FP and RC+F, respectively), and prepared in three forms (songpyeon, seolgidduk, and chaldduk). Ninety subjects with at least one MetS risk factor were recruited for 6 weeks of dietary intervention. Sixty subjects were finally included for the analysis. Compared to the initial values, RC+FP group had decreased levels of fasting blood glucose (FBG), HOMA-IR and blood pressure after 6 weeks, whereas RC+F group didn't have significant changes in them. Regarding the improvement of individual MetS risk factors, RC+FP group showed significant reduction in FBG and blood pressures but RC+F group only had reduction in systolic blood pressure. After the intervention, a reduction in the number of MetS risk factors was greatert in the RC+FP group than in the RC+F group. In conclusion, Dietary fiber enriched rice cakes with or without polyphenols decreased the number and/or the levels of MetS risk factors. Polyphenol rich plant components may provide additional health benefits in controlling FBG and blood pressure.

Resistant starch improves insulin resistance and reduces adipose tissue weight and CD11c expression in rat OLETF adipose tissue

OBJECTIVE

CD11s/CD18 dimers induce monocyte/macrophage infiltration into many tissues, including adipose tissues. In particular, it was reported that β2-integrin CD11c-positive macrophages in adipose tissues are closely associated with the development of insulin resistance. The aim of this study was to determine whether intake of resistant starch (RS) reduces macrophage accumulation in adipose tissues and inhibits the development of insulin resistance at an early stage in Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

METHODS

Twenty-two-wk-old male OLETF rats were fed a control diet (55% α-corn starch) or an RS diet (55% RS) for 5 wk. An oral glucose tolerance test was performed after 4 wk of feeding; tissues (mesenteric and epididymal adipose tissues, and liver) and tail vein blood were collected after 5 wk of feeding the test diets.

RESULTS

Feeding the RS diet to OLETF rats for 5 wk improved insulin resistance, reduced the mesenteric adipose tissue weight, and enhanced the number of small adipocytes. CD68 expression, a macrophage infiltration marker, was not changed by the RS diet, whereas the gene expression levels of integrins such as CD11c, CD11d, and CD18, but not CD11a, and CD11b, were significantly reduced. CD11c protein expression was reduced by the RS diet.

CONCLUSION

These findings suggest that part of the mechanism for the improved insulin resistance by the RS diet involves a reduction of CD11c expression in adipose tissues.

In vitro and in vivo digestion of octenyl succinic starch

This study aimed to understand effects of octenyl succinic anhydride (OSA) modification of normal corn (NCS) and high-amylose corn (HA7) starch on their enzymatic hydrolysis rates. After modification with 3% and 10% OSA, resistant starch (RS) contents of the cooked OS-NCS increased from 0.8% of the control starch to 6.8% and 13.2% (Englyst Method), respectively, whereas that of the cooked OS-HA7 decreased from 24.1% to 23.7% and 20.9%, respectively. When the cooked NCS, HA7 and OS (10%)-HA7 were used to prepare diets for rats at 55% (w/w) starch, RS contents of the diets were 1.1%, 13.2% and 14.6%, respectively. After feeding to the rats, 20.2-31.1% of the starch in the OS (10%)-HA7-diet was not utilized in vivo and was found in rat feces, which was substantially larger than that of the HA7-diet (≤4.9%) and NCS-diet (≤0.2%). The body weights of the rats, however, remained similar between different groups.

Inhibition of azoxymethane-induced preneoplastic lesions in the rat colon by a cooked stearic acid complexed high-amylose cornstarch

This study evaluated a novel stearic acid complexed high-amylose cornstarch (SAC) for the prevention of preneoplastic lesions in the colon of azoxymethane (AOM)-treated Fisher 344 rats fed resistant starches at 50-55% of the diet for 8 weeks. Uncooked SAC (r-SAC) diet was compared with raw normal-cornstarch diet (r-CS) or raw high-amylose cornstarch diet (r-HA), and water-boiled CS (w-CS) was compared with w-HA and w-SAC, respectively. w-SAC markedly reduced mucin-depleted foci (MDF) numbers compared with w-HA or w-CS. r-HA significantly decreased aberrant crypt foci (ACF) numbers compared with r-CS or r-SAC. Increased cecum weight and decreased cecum pH were observed in the SAC or HA groups. The highest amounts of total or individual short-chain fatty acids (SCFAs) in cecum and of butyrate or propionate in feces were observed in the AOM-treated w-SAC group. This study revealed the effectiveness of a novel resistant starch in inhibiting colonic preneoplastic lesions and the importance of high-moisture cooking on the suppression of colon carcinogenesis by this resistant starch.

Starch with high amylose content and low in vitro digestibility increases intestinal nutrient flow and microbial fermentation and selectively promotes bifidobacteria in pigs

Diets containing different starch types can affect enzymatic digestion of starch and thereby starch availability for microbial fermentation in the gut. However, the role of starch chemistry in nutrient digestion and flow and microbial profile has been poorly explained. Eight ileal-cannulated pigs (29.4 ± 0.9 kg body weight) were fed 4 diets containing 70% purified starch (amylose content, <5, 20, 28, and 63%; reflected by in vitro maximal digestion rate; 1.06, 0.73, 0.38, and 0.22%/min, respectively) in a replicated 4 × 4 Latin square. Ileal and fecal starch output, postileal crude protein yield, fecal total SCFA and total butyrate content, and gene copies of Bifidobacterium spp. in feces were higher (P < 0.05) when pigs consumed the slowly digestible starch diet than the remaining 3 starch diets. The in vitro starch digestion rate had a negative, nonlinear relationship with ileal starch flow (R(2) = 0.98; P < 0.001). Ileal starch flow was positively related to Bifidobacterium spp. (R(2) = 0.27; P < 0.01), Lactobacillus group (R(2) = 0.22; P < 0.01), and total butyrate content (R(2) = 0.46; P < 0.01) but was not related to Enterobacteriaceae (R(2) < 0.00; P = 0.92). In conclusion, starch with high amylose content and low in vitro digestibility increased postileal nutrient flow and microbial fermentation and selectively promoted Bifidobacterium spp. in the distal gut.

Chemical alterations with nutritional consequences due to pelleting animal feeds: a review

Pelleting is an energy-demanding process that is carried out on many animal feeds to assure a large macro-structure and thus improved handling properties and a high and homogenous feed intake. Due to the heat applied during conditioning and pelleting, some chemical alterations may take place. Proteins are to some extent denatured, and this will potentially improve nutritional value through inactivation of proteinous antinutrients, although may contribute negatively through inactivation of exogenous enzymes. Only a small fraction of the starch will be gelatinised, and pelleting will not affect starch digestibility to any considerable extent. Some vitamins, however, may be destroyed during the pelleting process, and viscosity of soluble fibres may increase.

Changes in mucosal alpha-glucosidase activities along the jejunal-ileal axis by an Hm-HACS diet intake are associated with decreased lipogenic enzyme activity in epididymal adipose tissue

Heat-moisture (hm)-high-amylose corn starch (HACS), which includes a larger amount of resistant starch than HACS or regular cornstarch (CS), is more indigestible in the small intestine than HACS or CS. An hm-HACS diet was also shown to ameliorate glucose intolerance and lipid abnormalities. This study examined the effects of feeding rats an hm-HACS diet for 14 days on the activities of mucosal alpha-glucosidase along the jejunal-ileal axis and lipogenic enzymes in epididymal adipose tissue. The contents in the lumen of the cecum were increased by feeding rats the HACS and hm-HACS diets, and the cecal weight was increased by the hm-HACS diet. The HACS diet reduced the activity of alpha-glucosidase in the upper jejunal mucosa, induced its activity in the upper ileal mucosa, reduced lipogenic enzyme activity in epididymal adipose tissue, and reduced serum triglyceride levels. These effects were more pronounced with the hm-HACS than with the HACS diet. These results suggest that feeding rats the hm-HACS diet reduced the activities of lipogenic enzymes in adipose tissue and alpha-glucosidase in the jejunal mucosa and induced the activity of alpha-glucosidase in the ileal mucosa compared with the HACS diet.

Hypolipidaemic effect of maize starch with different amylose content in ovariectomized rats depends on intake amount of resistant starch

The effect of amylose content on digestibility of starch in the small intestine and on the concentration of plasma lipid were studied in ileorectostomized rats and in ovariectomized rats, respectively. Seven kinds of starch with different amylose content (0, 27, 54, 62, 76, 79, 86 %) were used as test starch, which contained 0·4, 5·6, 37·1, 40·2, 45·6, 36·9 and 36·1 % resistant starch (RS), respectively. Rats were fed one of test diets containing 30 % test starch with different amylose content for 14 d in ileorectostomized and for 21 d in ovariectomized rats. Food intake was not significantly different among the groups. In ileorectostomized rats, the small intestinal starch digestibility decreased with increasing intakes of amylose and RS. In ovariectomized rats, body weight gain was lower on the higher amylose maize starch diets. The concentrations of plasma TAG and cholesterol decreased with increasing intake of RS. The concentrations of liver total lipids and TAG decreased with increasing intake of RS, but that of liver cholesterol did not. There was significant positive correlation between the level of sterol regulatory element-binding protein-1c mRNA and concentration of liver TAG. Total SCFA amount in the caecum increased logarithmically with increasing dry weight of caecal contents. The amount of bile acids in the small intestinal content and the excretions of bile acids and neutral steroids in faeces increased with increasing RS intake. These results show that starch rich in RS is more effective in preventing ovarian hormone deficiency-induced hyperlipidaemia.

Heat-moisture treatment of high-amylose corn starch increases dietary fiber content and lowers plasma cholesterol in ovariectomized rats

The effect of dietary high-amylose corn starch (HACS) of varying dietary fiber (DF) content on plasma cholesterol was examined in ovariectomized (OVX) rats. Gelatinized normal corn starch (G-CS) was used as a reference. OVX rats were fed a fiber-free purified diet containing G-CS, HACS, gelatinized high-amylose corn starch (G-HACS), or heat-moisture treated HACS (HM-HACS) at 400 g starch/kg diet for 21 d. The DF content of G-CS, HACS, G-HACS, and HM-HACS measured by the AOAC method was 0.1, 19.3, 2.4, and 64.5 g/100 g, respectively. The dry weight of cecal contents, cecal wall weight, the amount of short chain fatty acids in cecal contents, the amount of bile acids in small intestinal contents, and fecal excretion of neutral sterols increased logarithmically with increasing DF, while total plasma cholesterol concentration decreased. On the other hand, hepatic CYP7A1 activity, fecal dry weight, and fecal excretion of bile acids increased linearly with increasing DF, while body weight gain decreased. The hypocholesterolemic effect of HACS in OVX-rats appeared to be more effective by heat-moisture treatment.

Short-chain fatty acid formation in the hindgut of rats fed oligosaccharides varying in monomeric composition, degree of polymerisation and solubility

The contents of short-chain fatty acids were investigated in rats fed lactitol, lactulose and four fructo-oligosaccharides of different degree of polymerisation and solubility. Fructo-oligosaccharides with a low degree of polymerisation (2–8) generated the highest levels of butyric acid all along the hindgut, whereas fructo-oligosaccharides with a high degree of polymerisation (10–60) generated the highest levels of propionic acid. These specific differences were also generally reflected in the caecal pools and molar proportions of short-chain fatty acids. The lower solubility of the fructo-oligosaccharides was related to a lower degree of caecal fermentation. Lactulose and lactitol yielded high proportions of acetic acid and low proportions of butyric acid. It is concluded that both the degree of polymerisation and the solubility may affect short-chain fatty acid formation, whereas the fructose contentper seseem to be of less importance. This may be of interest when designing foods with specific health effects.

Rapid determination of short-chain fatty acids in colonic contents and faeces of humans and rats by acidified water-extraction and direct-injection gas chromatography

Short-chain fatty acids (SCFAs) have attracted much attention recently because of their positive physiological effects. In this work, a rapid and reliable gas chromatographic method for determination of eight SCFAs, in colonic and faecal samples from rats and humans has been developed and validated. The methodology involves extraction of the SCFAs in water before a direct injection procedure on a FFAP capillary column. A stock standard solution containing acetic acid, propionic acid, n-butyric acid, i-butyric acid, n-valeric acid, i-valeric acid, n-caproic acid and n-heptanoic acid was prepared and used. A high linearity (r2 > 0.9990), low quantification limit (2.38-30.14 microm) and high recovery for most acids were obtained. Acidification of faecal samples was found to be crucial for quantitative determination of the SCFAs, and adjustment of pH to 2-3 was regarded as necessary. Glass wool inserted in the glass liner of the injection port proved effective in preventing the contamination of the column by non-volatiles, and 12% formic acid reduced the ghost peak that appeared gradually after several injections. After validation, the methodology was applied on two faecal samples from rats fed diets containing different amount of dietary fibre and one faecal sample from human fed a normal diet to test the accuracy of the developed method.

Interactions of high amylose starch and deoxycholic acid on gut functions in rats

OBJECTIVE

This study evaluated whether high amylose cornstarch (HAS) could prevent adverse physiologic effects induced by deoxycholic acid (DCA) in the gut of rats.

METHODS

Thirty-two male Sprague-Dawley rats were provided with a low amylose cornstarch (LAS) diet or a 50/50 mixture of LAS and HAS diets for 4 wk; each of these diets was supplemented with 0 or 2 g of DCA per kilogram of diet. Therefore, there were four groups.

RESULTS

Cecal content pH was lower in rats fed the HAS diets compared with rats fed the LAS diets (P < 0.05). Bifidobacteria number in cecal contents, cecal pools of acetate, butyrate, and total short-chain fatty acids were highest in rats fed the HAS diet; moreover, the HAS/DCA diet resulted in increased Bifidobacteria growth and short-chain fatty acid production numerically compared with the LAS/DCA diets (P = 0.06). Production of prostaglandin-E2 in colonic mucosa was highest in rats fed the LAS/DCA diet, and the intake of HAS significantly decreased prostaglandin-E2 levels (P < 0.05).

CONCLUSIONS

In this study, DCA may have inhibited fermentation in the large intestine and increased prostaglandin-E2 production, and concurrent administration of HAS and DCA may have decreased the adverse effects on the gut induced by DCA.

The resistant starch level of heat moisture-treated high amylose cornstarch is much lower when measured in the human terminal ileum than when estimated in vitro

According to the definition of resistant starch (RS), the true value of foodstuff-derived RS can be assessed only from that found in the contents of the terminal ileum. To date, a few methods exist for in vivo measurement of RS in the terminal ileum, but their accuracy is questionable. The aim of this study was to quantify the level of RS in the terminal ileum to determine its true value as dietary fiber (DF). Volunteers (n = 7 men) were given a test meal containing 10 g of heat moisture-treated high amylose cornstarch (HMT-HAS) containing 8.8 g of RS as measured by Englyst's method. A double-lumen tube was positioned in the terminal ileum using the endoscopic retrograde bowel insertion method (ERBI). Intestinal contents were aspirated, and the amount of RS was measured as the glucose concentration (Englyst's method), and compared with the values for RS administrated orally using the same method. The mean amount of HMT-HAS-derived RS collected in the terminal ileum was 3.37 +/- 0.95 g (mean +/- SD), which was 34.5 +/- 9.7% of the in vitro RS value. Furthermore, there were large individual differences in recoveries, ranging from 22.2 to 47.5%. The measured amount of HMT-HAS-derived RS was much smaller in our in vivo study than that measured in vitro, suggesting that in vitro measurement may inaccurately estimate the RS and DF levels of foodstuffs. The problem is further compounded by the large individual in vivo variations in RS values from subjects consuming identical diets.

Effect of resistant starch from corn or rice on glucose control, colonic events, and blood lipid concentrations in streptozotocin-induced diabetic rats

To examine the effect of two types of resistant starch on blood glucose and insulin levels, colonic events, hypolipidemic actions and humoral immune responses, Sprague-Dawley streptozotocin-induced diabetic rats were fed diet containing resistant starch from corn or rice. The marked body weight loss by inducing diabetes was not recovered by feeding resistant starch, even though there are no differences in food intakes compared to the non-diabetic control rats. No significant effect of resistant starch feeding on blood glucose and insulin was found. Even though the length of small intestines, and cecum, colon and rectum together with the tissue weight of cecum were not affected by feeding resistant starch, the intestinal transit time was markedly shortened by both types of resistant starch and resistant starch from corn had a more pronounced effect. The short chain fatty acids in the intestinal contents did not appear to be different among the groups. Nonetheless, both of resistant starch from corn and rice significantly lowered plasma total lipid and cholesterol concentrations compared to the diabetic control. The total liver cholesterol lowering effect was observed with resistant starch from rice. Neither immunoglobulin G nor C(3) were influenced by resistant starch.