High Amylose Cornstarch Diet Research Articles

The interactivity of sources and dietary levels of resistant starches – impact on growth performance, starch, and nutrient digestibility, digesta oligosaccharides profile, cecal microbial metabolites, and indicators of gut health in broiler chickens

In a 21-d study, 480 Cobb 500 (off-sex) male broiler chicks were used to investigate the effects of feeding different sources and levels of resistant starches (RS) on growth performance, nutrient and energy utilization, and intestinal health in broiler chickens. The birds were allocated to 10 dietary treatments in a 3 × 3 + 1 factorial arrangement. The factors were 3 RS-sources (RSS): banana starch (BS), raw potato starch (RPS), and high-amylose corn starch (HCS); each at 3 levels (RSL) 25, 50, or 100 g/kg plus a corn-soybean meal control diet. Birds and feed were weighed on d 0, 8, and 21. On d 21, samples of jejunal tissue and digesta were collected for chemical analysis. Data were analyzed using the mixed model procedure of JMP with factor levels nested with the control. In the 0 to 21 phase, the birds fed the RPS diets had higher (P = 0.011) FI than those fed HCS or control diets, and FCR was greater (P = 0.030) in birds that received BS diets than in other diets. RSS × RSL was significant (P < 0.05) for total tract nutrient retention, AME, and AMEn on d 21. The starch digestibility was higher (P < 0.001) in birds that received the control diet than in RS diets, and decreased as RS levels increased, except for HCS. The apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) were higher (P < 0.001) in birds fed 100 g/kg HCS diet, with both decreasing with increasing levels of BS and RPS, except for HCS. Relative ileal oligosaccharides profile showed significant (P < 0.05) RSS × RSL with a higher relative abundance of Hex(3) (P = 0.01) and Pent(3) (P = 0.001) in HCS diets. In conclusion, RS may influence gut health and growth performance in broiler chickens through modulation of cecal SCFA and nutrient digestion, but these depend largely on the botanical origin and concentrations of individual RS.

Lentil ( Lens culinaris Medikus) Diet Affects the Gut Microbiome and Obesity Markers in Rat.

Lentil, a moderate-energy high-protein pulse crop, provides significant amounts of essential nutrients for healthy living. The objective of this study was to determine if a lentil-based diet affects food and energy intake, body weight, percent body fat, liver weight, and body plasma triacylglycerols (TGs) as well as the composition of fecal microbiota in rats. A total of 36 Sprague-Dawley rats were treated with either a standard diet, a 3.5% high amylose corn starch diet, or a 70.8% red lentil diet for 6 weeks. By week 6, rats fed the lentil diet had significantly lower mean body weight (443 ± 47 g/rat) than those fed the control (511 ± 51 g/rat) or corn (502 ± 38 g/rat) diets. Further, mean percent body fat and TG concentration were lower, and lean body mass was higher in rats fed the lentil diet than those fed the corn diet. Fecal abundance of Actinobacteria and Bacteriodetes were greater in rats fed the lentil or corn starch diets than those fed the control diet. Fecal abundance of Firmicutes, a bacterial phylum comprising multiple pathogenic species, decreased in rats fed the lentil and high-amylose corn starch diets vs the control diet. The lentil-based diet decreased body weight, percent body fat, and plasma triacylglycerols in rats and suppressed intestinal colonization by pathogens.

Sufficient intake of high amylose cornstarch maintains high colonic hydrogen production for 24h in rats.

Colonic hydrogen (H2) can suppress oxidative stress and damage in the body. We examined the minimum requirement of high amylose cornstarch (HAS) to maintain high colonic H2 production for 24h. Ileorectostomized and sham-operated rats were fed a control diet supplemented with or without 20% HAS for 7days. Colonic starch utilization was determined. Next, rats were fed the control diet with or without 10% or 20% HAS for 14 or 28days, respectively. Breath and flatus H2 excretion for 24h was measured. 1.04g of resistant fraction in HAS was utilized for 24h by colonic bacteria. High H2 excretion was not maintained for 24h in rats fed the 10% HAS diet, from which only 0.89g of resistant starch was estimated to be delivered. High colonic H2 production for 24h would be maintained by delivering more HAS to the large intestine than is utilized.

Isomaltodextrin, a highly branched α-glucan, increases rat colonic H₂ production as well as indigestible dextrin.

Colonic hydrogen (H2) protects against inflammation-induced oxidative stress. We examined the effect of a new highly branched α-glucan, isomaltodextrin (IMD), on colonic H2 production in rats. Rats were fed a 16.7% IMD, 8.8% indigestible dextrin (ID), or 10.4% high amylose cornstarch diet (Expt. 1), were fed diets containing 3.3-16.7% IMD (Expt. 2), or were fed diets containing 16.7% IMD or 5.2% fructooligosaccharide (FOS) (Expt. 3), for 14 days. Compared with the control group, feeding IMD or other α-glucans dose dependently and significantly increased H2 excretion and portal H2 concentration. The ability of IMD to increase H2 production was not inferior to that of FOS. The cecal Firmicutes/Bacteroidetes ratio in the IMD group was 5-14% of that in the control group. The cecal abundance of bifidobacteria was significantly greater in the IMD group than in the control group. Taken together, IMD, as well as other α-glucans, significantly increased colonic H2 production in a dose-dependent manner.

Resistant starch promotes vitamin D balance and maintenance of methyl group metabolism in type 1 diabetic rats (1041.8)

Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by pancreatic beta cell dysfunction, insulin deficiency and abnormal carbohydrate metabolism. Chronic hyperglycemia causes structural damage to the kidneys, resulting in ultrafiltration and imbalance of nutrients such as vitamin D and disruption of various proteins associated with methyl group metabolism and homocysteine regulation. Using streptozotocin (STZ)‐treated rats as a model of T1DM, we have demonstrated that dietary resistant starch (RS) attenuates many complications associated with T1DM including increased urinary excretion of 25,OH vitamin D and vitamin D binding protein. The focus of this study was to further characterize the impact of RS on vitamin D balance and methyl group metabolism in diabetic rats. Female rats (n=36) were randomly assigned to 1 of 3 groups: control, T1DM and T1DM + dietary RS. Control and T1DM rats were fed a standard cornstarch diet during the 8‐wk treatment period, whereas T1DM + RS groups were fed a high amylose cornstarch diet (36% resistant to digestion). T1DM rats exhibited polyuria, hyperglycemia, decreased urinary creatinine excretion (2.3 fold) and increased hepatic (1.2 fold) and renal (~2 fold) GNMT activity. Dietary RS attenuated these complications. Future research will focus on understanding the mechanism by which dietary RS promotes regulation of vitamin d and methyl group metabolism.Body characters no spaces: 1217 / Body characters with spaces: 1428 Total characters no spaces: 1455Grant Funding Source: Supported by Plant Sciences Institute, Iowa State University

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.

Changes in Mucosal α-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.

Abstract B136: Inhibition of azoxymethane-induced mucin depleted foci in the rat colon by a novel resistant starch

Abstract B136 The purpose of this study was to test the inhibitory effects of a novel resistant starch on azoxymethane (AOM)-induced colon carcinogenesis in rats. The novel resistant starch was processed from a commercial high amylose cornstarch(patent pending). Three groups of 5-week-old male Fischer 344 rats including 15 animals each were injected with AOM and fed normal cornstarch diet, high amylose cornstarch diet, and novel resistant starch diet respectively. Another three groups of male Fischer 344 rats with 5 animals in each group were injected with saline and fed the same three kinds of diets as control groups. Two injections were performed one week apart. Each of the 3 diets contained 55% water boiled high moisture starch, together with 45% of other ingredients necessary for rats’ nutritive requirements. The rats were fed with the above diets for 9 weeks after the second injection and then killed. Liver weight, caecal fermentation (caecum weight and pH), and a predictor of carcinogenicity - Mucin Depleted Foci (MDF) - were investigated. MDF were only seen with AOM treatment and were significantly reduced in rats fed novel resistant starch diet in comparison with rats fed the other two diets. Increased caecum weight and decreased caecum pH were also observed in the novel resistant starch diet group in comparison with the other two diet groups. No significant difference was found comparing liver weights. These results suggested that the novel resistant starch, which is less digestible than regular cornstarch or commercial high amylose cornstarch, may inhibit colonic carcinogenesis, and the inhibition might be related to increased caecal fermentation. Citation Information: Cancer Prev Res 2008;1(7 Suppl):B136.

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-E 2 in colonic mucosa was highest in rats fed the LAS/DCA diet, and the intake of HAS significantly decreased prostaglandin-E 2 levels ( P < 0.05). Conclusions In this study, DCA may have inhibited fermentation in the large intestine and increased prostaglandin-E 2 production, and concurrent administration of HAS and DCA may have decreased the adverse effects on the gut induced by DCA.

Ingestion of resistant starch protects endotoxin influx from the intestinal tract and reduces D-galactosamine-induced liver injury in rats.

The aim of the present study was to examine the protective effect of a dietary high-amylose cornstarch (HAS) against D-galactosamine (D-GalN)-induced liver injury, focusing specifically on intestinal endotoxin translocation. Male Wistar rats fed a HAS-free basal diet or a 30% HAS-supplemented diet were injected intraperitoneally with D-GalN. Serum transaminase activities, serum concentrations of tumor necrosis factor (TNF)-alpha, and portal venous endotoxin concentrations were determined at various time points. Ileal mucosal proliferation, small intestinal immunoglobulin (Ig)A and mucin, and the size of the cecal short-chain fatty acids (SCFA) pool were also determined. High-amylose cornstarch ingestion significantly reduced the increase in serum transaminase activities at 22 h after the injection of D-GalN. Rats fed the HAS diet showed a greater cecal SCFA production as measured by pool size than those fed the basal diet. Luminal IgA and mucin content were significantly greater in rats fed the HAS diet. Protein, DNA and RNA contents in the ileal mucosa were also higher in rats fed the 30% HAS diet. In a further experiment, portal venous endotoxin concentrations in rats fed the basal diet reached 72 ng/L at 4 h after D-GalN administration, but endotoxin was not detected in rats fed the HAS diet. At this time, portal endotoxin concentrations were significantly and positively correlated with the serum concentrations of TNF-alpha and serum alanine aminotransferase activities. These data support the view that HAS ingestion may reduce D-GalN-induced liver injury as a result of an inhibitory effect on endotoxin influx from the intestinal tract, at least in part as a result of alterations in the mucosal barrier functions.

Dietary Resistant Starch Alters the Characteristics of Colonic Mucosa and Exerts a Protective Effect on Trinitrobenzene Sulfonic Acid-induced Colitis in Rats

The protective effect of a dietary high-amylose cornstarch (HAS) against trinitrobenzene sulfonic acid (TNBS)-induced colitis was examined in rats. Rats were fed a HAS-free basal diet or, a 15% or 30% HAS supplemented diet for 10 d, and then received intracolonic TNBS to induce colitis and fed the respective diets for a further 8 d. HAS ingestion significantly protected colonic injuries as evidenced by lower colonic myeloperoxidase activity. Rats fed the HAS diet showed greater cecal short-chain fatty acid (SCFA) production than those fed the basal diet. Further, just before TNBS administration, HAS ingestion dose-dependently increased fecal and cecal mucin contents, and protein and nucleic acid contents in the colonic mucosa. HAS ingestion also reduced colonic permeability. The protective effect of HAS ingestion on TNBS-induced colitis is perhaps exerted through alterations in colonic mucosa, possibly due to cecal SCFA production.

Apparent Mineral Retention Is Similar in Control and Hyperinsulinemic Men after Consumption of High Amylose Cornstarch

The effects on apparent mineral retention after long-term consumption of a high amylose diet containing 30 g resistant starch (RS) were investigated in 10 control and 14 hyperinsulinemic men. Subjects consumed products (bread, muffins, cookies, corn flakes and cheese puffs) made with standard (70% amylopectin, 30% amylose; AP) or high amylose (70% amylose, 30% amylopectin; AM) cornstarch for two 14-wk periods in a crossover pattern. Starch products replaced usual starches in the habitual diet for 10 wk followed by 4 wk of consuming the controlled diets. During wk 12, all urine, feces and duplicate foods were collected for 7 d. Urinary chromium losses after a glucose tolerance test or 24-h collections of the hyperinsulinemic and control subjects did not differ and were not altered by diet. Except for zinc, the two subject types did not differ significantly in apparent mineral balance. Apparent retentions of calcium and magnesium were not significantly affected by diet (AM vs. AP) or type-by-diet interaction. Apparent iron retention tended to be greater after AM than AP consumption (P < 0.09). Apparent copper retention was greater after consuming AP than after AM (P < 0.02), whereas apparent zinc retention was greater after consuming AM than after AP (P < 0.018). Zinc also showed a significant type-by-diet interaction (P < 0.034) with control subjects retaining less zinc after consuming AP than after AM. In summary, a high amylose cornstarch diet containing 30 g RS could be consumed long term without markedly affecting, and possibly enhancing, retention of some minerals.

Psyllium Shifts the Fermentation Site of High-Amylose Cornstarch toward the Distal Colon and Increases Fecal Butyrate Concentration in Rats

We examined the combination effects of psyllium (PS) and resistant starch on large bowel short-chain fatty acids (SCFA). Rats were fed one of the following four diets: low amylose (LAS) or high amylose cornstarch diets (HAS, 50 g/kg diet) with or without 15 g PS/kg diet (LAS/PS and HAS/PS diets). HAS and/or PS were substituted for the same amounts of LAS in diets. Cecal butyrate concentrations were significantly higher in rats fed the HAS and HAS/PS diets than in those fed the LAS and LAS/PS diets. However, butyrate and total SCFA concentrations in rats fed the HAS diet decreased along the length of the colon and fecal butyrate concentration was reduced to one-third of that in the cecum. In contrast, the HAS/PS diet maintained higher butyrate concentrations throughout the large bowel. Fecal butyrate concentration in the HAS/PS diet-fed group significantly exceeded the sum of the concentrations in rats fed the LAS/PS and HAS diets. PS supplementation to the HAS diet significantly increased fecal starch excretion by 10 fold compared with that of rats fed the HAS diet. There was a positive correlation between fecal butyrate concentration and fecal starch excretion (r = 0.709, P < 0.0001). In a further experiment, ileorectostomized rats were fed the HAS and HAS/PS diets. From the difference in fecal starch excretion between normal and ileorectostomized rats, starch degradation by large bowel microflora in rats fed the HAS and HAS/PS diets was deduced to be 96% and 63%, respectively. These findings support the hypothesis that PS may delay the fermentation rate of HAS in the cecum and shift the fermentation site of HAS toward the distal colon, leading to the higher butyrate concentration in the distal colon and feces.

High amylose corn starch retarded 7, 12-dimethylbenz[ a]anthracene - induced mammary tumor development in female rats

The present study was planned to examine the effect of partial replacement of corn starch (CS) with high amylose corn starch (HAS) on mammary tumor progression. The first experiment was to evaluate the effects of HAS on 7, 12-dimethylbenz[ a]anthracene (DMBA)-induced mammary tumor progression. Two days after DMBA administration (31 mg/kg body weight of rat) at age of 49 days, rats were assigned into 3 groups and fed one of the three experimental diets including CS, 30% HAS and 13.6% wheat bran (WB), respectively. The rats were examined weekly for palpable mammary tumors for 112 days. In the middle of experimental period, cumulative palpable tumors per tumorbearing rat were significantly lower in rats fed the HAS and WB diets than in those fed the CS diet. At autopsy, both mean tumor number and weight per tumor bearing rat were reduced by 10∼30% in rats fed the HAS and WB diets compared with those in the CS diet, but these differences were not significant. Serum estradiol-17 β concentration did not differ among rats fed the CS, HAS and WB diets, although fecal excretion of estradiol-17 β in rats fed the WB diet was significantly higher than those in rats fed the CS and HAS diets. In the second experiment, digestibilities of HAS and CS were compared in ileorectostomized rats. The results showed that only 66% of HAS were digested in the small intestine, whereas CS was digested up to 99%. In the 3rd experiment, postprandial blood glucose concentrations in rats intubated HAS suspension were significantly depressed when compared with that in rats intubated CS suspension. These results suggest that a mild energy restriction in HAS feeding is effective in prevention of mammary tumor progression.