Article

Effect of Gum Arabic on Glucose Levels and Microbial Short-Chain Fatty Acid Production in White Rice Porridge Model and Mixed Grain Porridge Model

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Abstract

White rice porridge and mixed grain porridge, which are often consumed in many countries, were used as two models to evaluate the effects of gum arabic on glucose levels and microbial short-chain fatty acids (SCFA). Gum arabic was incorporated into the two porridges individually. Apparent viscosity of the two porridges was significantly increased, and their glucose productions during gastrointestinal digestion were notably lowered (p < 0.05). Diffused glucose amount was both significantly decreased resulted from gum arabic addition (p < 0.05). Furthermore, blood glucose rise after oral administration of porridges in mice was considerably lowered after fortified with gum arabic (p < 0.05). Microbial SCFA production during in vitro fermentation of porridges was both significantly increased after gum arabic addition, which may also have beneficial effects on reducing postprandial glycemic response. Therefore, gum arabic may be a helpful ingredient which could be added in porridges to have benefits for the reduction of postprandial glycemic response.

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... Animal and human studies have also shown GA can reduce fasting blood glucose suggesting that it may be beneficial in the treatment of diabetes (Nasir, 2014;Babiker et al., 2018;Jarrar et al., 2021). The mechanism is partly related to increased viscosity of food as well as lowering of glucose production, and increased SCFA production (Nasir et al., 2010(Nasir et al., , 2014Hu et al., 2014). However, there is a lack of data regarding the effects of GA on diabetes-related cognitive decline and related neurodegenerative changes. ...
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The aim was to determine whether gum Arabic (GA) supplementation prevents cognitive decline in type 2 diabetes, through stimulation of mitochondrial function in the hippocampus. Type 2 diabetic rats and controls were assigned to following groups for 16 weeks: Control + Water; Control + GA 10% w/v; Diabetes + Water; Diabetes + GA 10% w/v. Latency in water maze was shorter for Diabetes + GA compared to Diabetes + Water (P < 0.05). Diabetes + GA group had a higher expression density per cell of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) compared to Diabetes + Water (P < 0.05). A similar trend was observed for ATP synthase β-subunit expression (ATPB). Number of PGC-1α positive cells was higher in diabetes compared to control groups (p < 0.05). The GA prevented learning and memory loss in type 2 diabetes. This was associated with greater expression of PGC-1a and a trend for greater ATBP protein expression in the hippocampus.
... AG is often used as a stabilizer, thickening agent, and emulsifier in the food industry [20], but its effects on blood glucose, satiety, food intake, and weight status in healthy humans lack clarity. Limited research has shown benefits of AG consumption for satiety [21] and weight control [22][23][24] as well as glucose absorption and postprandial blood glucose response [24,25], although studies on weight control in humans come exclusively from one lab group [22][23][24] and studies on blood glucose control used only subjects already diagnosed with T2D. Overall, human and animal trials show excellent intestinal tolerance and safety for relatively high levels of AG supplementation. ...
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Acacia gum (AG) is a non-viscous soluble fiber that is easily incorporated into beverages and foods. To determine its physiological effects in healthy human subjects, we fed 0, 20, and 40 g of acacia gum in orange juice along with a bagel and cream cheese after a 12 h fast and compared satiety, glycemic response, gastrointestinal tolerance, and food intake among treatments. Subjects (n = 48) reported less hunger and greater fullness at 15 min (p = 0.019 and 0.003, respectively) and 240 min (p = 0.036 and 0.05, respectively) after breakfast with the 40 g fiber treatment. They also reported being more satisfied at 15 min (p = 0.011) and less hungry with the 40 g fiber treatment at 30 min (p = 0.012). Subjects reported more bloating, flatulence, and GI rumbling on the 40 g fiber treatment compared to control, although values for GI tolerance were all low with AG treatment. No significant differences were found in area under the curve (AUC) or change from baseline for blood glucose response, although actual blood glucose with 20 g fiber at 30 min was significantly less than control. Individuals varied greatly in their postprandial glucose response to all treatments. AG improves satiety response and may lower peak glucose response at certain timepoints, and it is well tolerated in healthy human subjects. AG can be added to beverages and foods in doses that can help meet fiber recommendations.
... Particularly, Bifidobacterium longum exhibited growth preference in arabinan glycan compared to xyloglucan, β-glucan and pectin in vitro ). Furthermore, the enhanced production of intestinal acetic acid and propionic acid by a diet supplemented with gum arabic was possibly positively related to the maintenance of blood glucose (Hu et al. 2014) (Fig. 1). ...
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The human gut microbiota respond to particular food components, interact with intestinal mucosa and thereby contribute to health and diseases. Key microbiome features are under comprehensive investigation and are likely to be developed as reliable evidences for clinical diagnosis. And the underlying mechanisms lay the foundation of assembling bespoke nutritional ingredients including functional food additives that may lead to favorable outcomes in facilitating amelioration of host dysfunctions. Functional hydrocolloids serve as multiple food additives with promising application prospects and outstanding adjunctive beneficial characteristics. Therefore, in this review, we introduce the latest advances in food additives-gut microbiota-host axis by summarizing the physiochemical and physiological properties of a collection of functional hydrocolloids from various sources, describing the functional hydrocolloids-related intestinal commensal markers, and deciphering the underlying mechanisms of their beneficial effects, and propose the feasibilities and guidelines for further developments of gut microbiota-oriented personalized nutrition.
... [11,12] Other studies concluded significant blood glucose concentration decrease after gum Arabic treatment in mice and Indian human subjects. [13][14][15] The oxidative stress parameters (CAT, SOD, GSH, and MDA) were studied by the research group of Ahmed AA in three groups of rats. The three groups were normal, diabetic induced by alloxan, and diabetic treated with gum Arabic. ...
... Most of the published papers suggested that hydrocolloids could retard starch digestion rate in food systems e.g. SA in rice dough (Koh et al., 2009) and arabic gum in highamylose rice noodles (Bae et al., 2019) and in mixed grain porridge (Hu et al., 2014). Although, some suggested that hydrocolloids could increase the rate of starch digestion in fermented rice noodles (Srikaeo et al., 2018). ...
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Waxy rice which has been soaked in excessive water was cooked with hydrocolloid solutions, corresponding to hydrocolloid concentrations of 0.3, 0.5 and 0.7 g/100 g rice. Hydrocolloids studied were guar gum (GG), xanthan gum (XG) and sodium alginate (SA). The hydrocolloid-cooked rice and the control sample, cooked in water without any hydrocolloid, were determined for their starch retrogradation, texture, microstructure and in-vitro starch digestion rate. It was found that hydrocolloid-cooked rice exhibited more retrograded starch than the control, providing high melting enthalpies. Retrograded starch caused the increased hardness of the cooked rice during storage, while adhesiveness and springiness tended to decrease. Although, hydrocolloid-cooked rice retrograded more during storage, it showed a lower hardness than the control sample due to the phase separation of hydrocolloids. SEM images revealed that intact starch was completely gelatinized. The control sample provided denser microstructure than the hydrocolloid-cooked samples. While air cells were observed in the hydrocolloid-cooked samples especially with XG. The hydrocolloid-cooked rice exhibited lower starch digestion rate than the control. SA provided the lowest starch digestion rate, followed by GG and XG respectively.
... Addition of GA in both food models exhibited an increased viscosity, and lowering of glucose production. Further, oral administration of GA fortified porridges in mice had a glucose lowering effects, suggesting its role in the reduction of postprandial glycaemic response [19]. In another study, GA (10% w/w) supplementation to HFD fed mice for 12 weeks showed a decrease in visceral adipose tissue, blood glucose and plasma lipids, whereas no effects in plasma triglycerides levels were observed. ...
... [11,12] Other studies concluded significant blood glucose concentration decrease after gum Arabic treatment in mice and Indian human subjects. [13][14][15] The oxidative stress parameters (CAT, SOD, GSH, and MDA) were studied by the research group of Ahmed AA in three groups of rats. The three groups were normal, diabetic induced by alloxan, and diabetic treated with gum Arabic. ...
Chapter
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This study aimed at assessing the effect of gum arabic (Acacia senegal) oral treatment on the metabolic profile of chronic renal failure (CRF) patients. A total of 36 CRF patients (under regular haemodialysis) and 10 normal subjects participated in this study. The patients were randomly allocated into three groups-group A: 12 CRF patients under low-protein diet (LPD) (<40 g day(-1)) and gum arabic (50 g day(-1)) treatment; group B: 14 CRF patients under LPD and gum arabic, iron (ferrous sulphate, 200 mg day(-1)) and folic acid (5 mg day(-1)) treatment; group C (control group): 10 CRF patients under LPD and iron and folic acid treatment and group D: 10 normal volunteers (on normal diet) under daily dose of 50 g gum arabic. Each of the above treatments was continued for three consecutive months. Blood samples were collected from each subject before treatment and twice per month "pre-dialysis" for 3 months. Biochemical parameters measured were: serum urea, serum creatinine, serum uric acid, serum calcium and serum phosphorus. By the end of the 3 months of treatment, serum urea levels significantly decreased by 31.2 and 44.18% for group A and B, respectively, compared with the baseline (0.01 < p < 0.001) and control group (p < 0.05). Serum creatinine levels significantly decreased in the groups of gum users (A, B and D) by 9.94, 12.65 and 11.7%, respectively, compared with the control group (p < 0.001). There was a significant decrease (p < 0.05) in serum uric acid levels by 14 and 19.9% for group A and B, respectively, compared with the baseline. Serum calcium levels increased by 12.64, 15.75 and 8.75% for group A, B and D, respectively, and these increases were significantly different (0.05 < p < 0.001) from baseline and control group for groups A and B. Serum phosphorus levels significantly decreased by 22.54% for group A, 17.69% for group B and 7.71% for group D, compared with the baseline (0.05 < p < 0.001). From this study, we conclude that oral administration of gum arabic could conceivably alleviate adverse effects of CRF.
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High-methoxyl pectin was degraded by dynamic high pressure microfluidization (DHPM). It was found that apparent viscosity, average molecular weight and particle size of pectin decreased, whereas the amount of reducing sugars increased with increasing DHPM pressure. At the same time, the surface topography of pectin was changed from large flake-like structure to smaller porous chips. The mechanism of DHPM-induced degradation of pectin was also investigated. Fourier transform infrared spectra showed DHPM had no effect on the primary structure of pectin. On the other hand, reducing sugars content increased linearly with decreasing average molecular weight, suggesting the degradation may derive from the rupture of glycosidic bond. The breakdown of glycosidic bond may not only result from intensive mechanical forces but also from acid hydrolysis, which was evidenced in the reduction of degradation when the concentration of H+ was lowered. In addition, neither β-elimination nor demethoxylation occurred with DHPM. Based on these results, a model was proposed to illustrate the degradation of pectin induced by DHPM.
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Sixty-four crossbred pigs averaging 24 kg liveweight were used to study the effects of dietary propionic acid (PA) on plasma and tissue cholesterol concentrations of pigs fed hypercholesterolemic diets for 10 wk. Four diets, based on barley, wheat and soybean meal, consisting of a control diet and a diet containing 10% tallow, both fed with and without the addition of 5% PA were used in this study. Addition of PA to the control diet decreased feed intake (ADF) by 16%, decreased average daily gain (ADG) by 8% and improved feed conversion efficiency (FCE) by 8%. Addition of tallow to the control diet resulted in a 15% reduction in ADF, a 3% improvement in ADG and an 18% improvement in FCE. When both tallow and PA were present, ADF was depressed 26%, ADG decreased 5% and FCE improved 23%. The addition of tallow significantly increased the levels of total plasma cholesterol while the addition of PA significantly decreased the plasma cholesterol levels in comparison with the control diet and prevented the increase noted in the tallow group. Addition of PA to the control diet significantly increased the cholesterol content of backfat and significantly reduced the cholesterol content of the kidneys. Addition of PA to the tallow diet significantly reduced the cholesterol content of kidneys, but did not significantly affect the cholesterol content of backfat. It is suggested that the increased cholesterol content of backfat in pigs fed diets containing PA reflects a reduced transport of cholesterol from peripheral tissues to the liver for excretion in the bile.
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Bioaccessibility and bioavailability of active ingredients (like vitamins, antioxidants, etc.) into food systems is often compromised by factors like low permeability and/or solubility within the gut, lack of stability during food processing (temperature and oxygen) as well as in the gastrointestinal tract (pH, enzymes, presence of other nutrients). Moreover, little is known on the influence of food structure and breakdown in the gut on nutrient release. The possibility of predicting the release of nutrients from food matrices under simulated gastrointestinal conditions is of great relevance in order to define which food matrix is best for which nutrient, as well as for looking at the interaction of ingredients with the enzymes involved in the digestive process. This study explores the potential relevance of dissolution tests as a tool for predicting bioaccessibility of nutrients during in vitro digestion. Whey protein hydrogels containing green tea extract (GTE) were chosen for this study. Different simulated in vitro gastrointestinal conditions (GI) were applied throughout the dissolution experiments and the GTE was analysed by UV–vis absorption spectroscopy. It was possible to distinguish between two different release kinetics when experiments were performed in simulated gastric or intestinal media. In the gastric step, the kinetic of GTE release was lower than in an intestinal environment, suggesting that more GTE is released and available for absorption into the intestine than in the stomach. The present study shows that it is possible to use the dissolution tester as a screening method to mimic nutrient release from a food matrix in the gastrointestinal tract.
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Cereal Chem. 74(3):293-296 High-fiber, high-carbohydrate diets, including foods with low glyce- mic index, have been associated with prevention and treatment of dis- eases such as coronary heart disease and diabetes. β-glucan, a soluble, viscous polymer found in oat and barley endosperm cell wa ll, was incor- porated into pasta test meals. Five fasted adult subjects were fed test meals of a barley and durum wheat blend pasta containing 100 g of avail- able carbohydrate, 30 g of total dietary fiber (TDF) and 12 g of β-glucan, or an all durum wheat pasta containing the same amount of available
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Salinomycin (AHR-3096) is a new polyether antibiotic prepared from a strain of Streptomyces albus. Four pens each of four castrated male and four female swine were allocated to each of the following treatments from 8 to 34 kg liveweight: basal corn-soy diet; basal diet supplemented with carbadox at 55 mg/kg; basal diet supplemented with salinomycin at 25 mg/kg; basal diet supplemented with salinomycin at 50 mg/kg. Mean daily feed intakes were 1.12, 1.22, 1.14 and 1.19 kg (P < 0.05); mean adjusted daily gains were 546, 626, 580 and 602 g (P < 0.001); and mean feed conversion (feed:gain), ratios were 2.05, 1.95, 1.97 and 1.93 (P < 0.05), respectively. Both salinomycin and carbadox improved daily liveweight gain and reduced feed:gain ratio.
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The study aims to explore the antihyperglycemic activity of Acacia tortilis polysaccharide isolated from the gum exudate. α-D-Glucosidase from Saccharomyces cerevisiae and rat small intestine was used as in-vitro model to assess α-D-glucosidase inhibitory activity of the polysaccharide against yeast and mammalian enzyme. The reduction in postprandial blood glucose level after carbohydrate rich diet fed to albino wistar rats was employed as in-vivo model of α-D-glucosidase inhibition. The study revealed α-D-glucosidase inhibitory activity of the polysaccharide in both in-vitro as well as in-vivo models. Therefore, polysaccharide isolated from Acacia tortilis plant gum exudate may be a potential drug for diabetes mellitus and its complications.
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Type 1 diabetes (T1D) is an autoimmune disease characterized by the selective destruction of pancreatic beta-cells. Although successful islet transplantation provides a promising treatment, high cost, lack of donor organs, immune-mediated destruction of transplanted islets, and side effects from immunosuppressive drugs greatly limit its uses. Therefore, the search for novel and cost-effective agents that can prevent or ameliorate T1D is extremely important to decrease the burden of T1D. In this study, we discovered that epicatechin (EC, 0.5% in drinking water), a flavonol primarily in cocoa, effectively prevented T1D in non-obese diabetic (NOD) mice. At 32 weeks of age, 66.7% control mice had overt diabetes, whereas only 16.6% EC-treated mice became diabetic. Consistently, EC mice had significantly higher plasma insulin levels but lower glycosylated hemoglobin concentrations compared to control mice. EC had no significant effects on food or water intake and body weight gain in NOD mice, suggesting that EC's effect was not due to alterations in these variables. Treatment with EC elevates circulating anti-inflammatory cytokine interleukin-10 levels, ameliorates pancreatic insulitis, and improved pancreatic islet mass. These findings demonstrate that EC may be a novel, plant-derived compound capable of preventing T1D by modulating immune function and thereby preserving islet mass.
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Mice (20.0 ± 2.0 g, n = 48 per group) were given 30 days oral administration of polysaccharide from Plantago asiatica L. seeds at the dose of 0.4 g/kg body weight by gavage to investigate the effects of the polysaccharide on mouse colon. Results showed that the concentrations of total short-chain fatty acids (SCFA), acetic, propionic and n-butyric acids in mouse colonic content of polysaccharide treated group were all significantly higher than that of control group (water) (p < 0.05). In addition, moisture of mouse colonic content of polysaccharide treated group was also notably higher than that of the control group (p < 0.05), indicating the intake of polysaccharide from P. asiatica L. resulted in a stronger water-holding capacity for colonic content throughout the experimental period. Furthermore, a decreased pH (from 7.5 ± 0.1 to 7.2 ± 0.1) was observed in mouse colon of the polysaccharide treated group compared with the control group (pH from 7.5 ± 0.1 to 7.5 ± 0.1). These results suggested that the intake of the polysaccharide from P. asiatica L. might be beneficial for the colon health.
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The determination of short-chain fatty acids produced by colonic fermentation can provide useful information as a tool to evaluate prebiotic effects of foods with beneficial effects on human health. In this study, we developed and validated a headspace solid-phase microextraction gas chromatographic–mass spectrometric method for the determination of underivatised short-chain fatty acids produced in an in vitro fermentation model. A divinylbenzene/Carboxen/polydimethylsiloxane fibre was used. Solid-phase microextraction conditions, i.e., extraction temperature, extraction time and salt addition were optimised by means of a central composite face-centred experimental design. The method was validated in terms of limit of quantification, accuracy, precision and linearity. The developed method was then applied to the analysis of short-chain fatty acids produced by the fermentation of faecal cultures derived from bread enriched with different kinds of dietary fibres.Highlights► Development of an HS-SPME method for the extraction of short-chain fatty acids (SCFAs). ► Optimisation of the SPME conditions by an experimental design. ► Validation of the method (limit of quantification, linearity, precision, and accuracy). ► Determination of SCFAs produced from fermentation of bread enriched with dietary fibre.
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Nonenzymatic browning due to the Maillard reaction between reducing sugars and glycine was studied in systems containing varying amounts of water, glycerol, and hydrophilic polymers. We observed that the browning rate decreased with increasing water content, except in systems in which mobility of reactants became substantially impeded at low water contents. The effect of water was complex and depended on the presence of various water-binding agents among other factors. The inhibitory effect of high water contents could be due to the fact that water is a product of several condensation steps in the browning reaction.
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Healthy subjects consumed D-glucose (glucose) alone or in the presence of oat gum prepared in a pilot plant (PPOG) or commercial guar gum (GG). Both gums significantly and similarly decreased the postprandial glucose rise as indicated by the glycemic index (GI). The effect of PPOG in a normal meal situation was studied by addition to cream of wheat (CW) to mimic oat bran (OB) porridge. Again, PPOG significantly lowered the postprandial glucose rise. Relative to CW alone, the GI of OB (62%) was similar to that of PPOG plus CW (60%). PPOG was less viscous than both GG and a laboratory-prepared sample of oat gum (LPOG). However, apparent viscosity differences between the gums decreased with increasing shear rate and concentration. LPOG was more pseudoplastic than GG, which in turn was more pseudoplastic than PPOG. At the concentration used in the acute meal tests, PPOG and GG reduced the rate of dialysis of glucose to a similar extent.
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The hypothesis that blood glucose levels influence memory was re-examined. The performance on two memory tests was quicker when breakfast had been taken, suggesting that the ability to retrieve memories had been facilitated. Performance on a spatial memory test correlated significantly with blood glucose levels.
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Gravimetric measurement of dietary fiber (DF) gives no indication of the biological function of any particular fiber. This study describes simple methods based on dialysis and fermentation that enable a hierarchy of fibers to be described for each of the major actions of fiber along the gastro-intestinal tract: nutrient absorption, sterol metabolism, cecal fermentation, and fecal bulking. These results were compared with previous metabolic studies with the same fiber isolates in humans. DF that modifies nutrient absorption can be identified by using dialysis studies, whereas identifying DF that modifies sterol metabolism, cecal fermentation, and fecal weight requires formulas that incorporate dialysis and fermentation results. Results from dialysis and fermentation predicted the action of wheat bran, pectin, guar, gum arabic, carboxymethylcellulose, gellan, tragacanth, xanthan, and karaya in humans and generated anomalous results for karaya and tragacanth. These methods could form the basis of techniques that would enable a screening of novel and processed fibers before studies in animals, including humans.
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The extent of carbohydrate digestion and absorption from two diets including either instant bean flakes (174 g/d) or potato flakes (102 g/d) was measured in seven ileostomy subjects during a 2-day period. Test foods contributed 40 per cent of the total dietary starch intake (160 g/d), the remainder coming from rice and white bread. Overall, 4 per cent and 0.7 per cent of the dietary starch consumed remained unabsorbed during the bean and potato periods, respectively. Between 9.0 and 10.9 per cent of dietary bean starch and less than 1.7 per cent of potato starch were not absorbed. Dietary fibre and resistant starch were completely recovered in ileostomy effluents. In separate meal tests with 40 g starch, beans gave lower blood glucose (P less than 0.05) and serum insulin (P less than 0.01) responses than potatoes. Dietary starch malabsorption from leguminous foods is less than previously estimated and does not explain the attenuated glycaemic and insulinaemic responses.
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Different starchy foods produce different glycemic responses when fed individually, and there is evidence that this also applies in the context of the mixed meal. Methods of processing, and other factors unrelated to the nutrient composition of foods may also have major effects on the glycemic response. The reason for differences in glycemic response appears to relate to the rate at which the foods are digested and the many factors influencing this. The glycemic index (GI) is a system of classification in which the glycemic responses of foods are indexed against a standard (white bread). This allows the results of different investigators to be pooled. GI values also depend upon a number of nonfood-related variables. The method of calculation of the glycemic response area is most important, but the method of blood sampling and length of time of studies also may have effects. Variability of glycemic responses arises from day-to-day variation in the same subject and variation between different subjects. There is less variability between the GI values of different subjects than there is within the same subject from day to day. Therefore, the mean GI values of foods are independent of the glucose tolerance status of the subjects being tested. Potentially clinically useful starchy foods producing relatively flat glycemic responses have been identified, including legumes, pasta, barley, bulgur, parboiled rice and whole grain breads such as pumpernickel. Specific incorporation of these foods into diets have been associated with reduced blood glucose, insulin, and lipid levels. Low-GI foods may influence amino acid metabolism although the implications of these are unknown. In addition, low GI foods increase colonic fermentation. The physiologic and metabolic implications of this relate to increased bacterial urea utilization, and to the production and absorption of short chain fatty acids in the colon. The application of the GI to therapeutic diets should be in the context of the overall nutrient composition of the diet. High-fat or high-sugar foods may have a low GI, but it may not be prudent to recommend these foods solely on the basis of the GI. It is therefore suggested that the most appropriate use of the GI is to rank the glycemic effects of starchy foods which would already have been chosen for possible inclusion in the diet on the basis of their nutritional attributes, i.e. low-fat, unrefined carbohydrate.
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The determine the effect of different foods on the blood glucose, 62 commonly eaten foods and sugars were fed individually to groups of 5 to 10 healthy fasting volunteers. Blood glucose levels were measured over 2 h, and expressed as a percentage of the area under the glucose response curve when the same amount of carbohydrate was taken as glucose. The largest rises were seen with vegetables (70 +/- 5%), followed by breakfast cereals (65 +/- 5%), cereals and biscuits (60 +/- 3%), fruit (50 +/- 5%), dairy products (35 +/- 1%), and dried legumes (31 +/- 3%). A significant negative relationship was seen between fat (p less than 0.01) and protein (p less than 0.001) and postprandial glucose rise but not with fiber or sugar content.
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The effects of propionate on serum and liver lipid concentrations were studied in cholesterol-fed rats. Both serum and liver cholesterol levels were significantly lower in rats fed the cholesterol-propionate diet than in rats fed the cholesterol diet without propionate. Liver triglyceride levels were also significantly lower in the propionate-treated group. Serum triglyceride concentrations were not influenced by the propionate feeding. Propionate intake was not associated with histologic changes in liver tissue. This study indicates that 0.5% sodium propionate-supplemented diets slightly but significantly reduced cholesterol accumulation in both serum and liver of cholesterol-fed rats. Thus propionate, a metabolic product of fiber fermentation, may mediate some of the hypocholesterolemic effects of certain soluble plant fibers.
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Exudative gums from two Australian Acacia species (A. pycnantha and A. baileyana) and gum arabic (from A. senegal) were fed to rats at graded levels (0, 20, 40, 80 g/kg), replacing cellulose in purified diets containing cholesterol plus cholic acid. Compared with consumption of the control diet containing cellulose only, consumption of the gums had no significant effects on concentrations of plasma or liver cholesterol. Plasma triacylglycerol concentrations were higher in rats fed gum arabic, whereas liver triacylglycerols were lower in rats fed the gums. The gums did not affect the total pool of volatile fatty acids in the ceca, as compared with results in controls, but did promote the relative contribution of propionate at the expense of acetate. In rats fed the diet containing cellulose (80 g/kg) the proportions of cecal acetate:propionate:butyrate were 76:15:9, whereas in the rats fed A. pycnantha gum, gum arabic and A. baileyana gum (80 g/kg) the ratios were 42:54: 4, 35:46:19 and 43:53:4, respectively. The low apparent fermentability of the gums was confirmed by the accumulation of non-starch polysaccharides in cecal digesta. In rats fed 80 g/kg A. pycnantha gum, 3.44 g of soluble non-starch polysaccharides was measured in the ceca, which was 58% of the dry weight of the cecal contents. We conclude that the biological activities of the Australian Acacia gums were similar to those of gum arabic and that these gums may have potential value as human food ingredients.
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The indigenous gastrointestinal (GI) tract microflora has profound effects on the anatomical, physiological and immunological development of the host. The indigenous microflora stimulates the host immune system to respond more quickly to pathogen challenge and, through bacterial antagonism, inhibits colonization of the GI tract by overt exogenous pathogens. Indigenous GI bacteria are also opportunistic pathogens and can translocate across the mucosal barrier to cause systemic infection in debilitated hosts.
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There have been many reports concerning the role of dietary fiber in lowering postprandial serum glucose, and the main mechanism was regarded as the viscosity of different dietary fibers in hampering diffusion of glucose and postponing absorption and digestion of carbohydrates. In this paper, two kinds of water-insoluble dietary fibers, water-insoluble dietary fiber of wheat bran and enzyme-resistant starch of maize amylose, and four kinds of water-soluble dietary fibers, water-soluble dietary fiber of wheat bran, carboxymethyl cellulose, guar gum, and xanthan gum, were used to investigate their postprandial serum glucose lowering mechanism in vitro. The results showed that these dietary fibers lowered postprandial serum glucose levels at least by three mechanisms. First, dietary fibers increase the viscosity of small intestine juice and hinder diffusion of glucose; second, they bind glucose and decrease the concentration of available glucose in the small intestine; and, third, they retard alpha-amylase action through capsuling starch and the enzyme and might directly inhibit the enzyme. All of these decreased the absorption rate of glucose and the concentration of postprandial serum glucose.
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Gum arabic, a high-molecular-weight natural polysaccharide, has been shown to have proabsorptive properties in animal models of gastrointestinal disease that involve nitric oxide (NO). Gum arabic may indirectly regulate NO metabolism by creating an outward NO gradient, thus altering other intracellular NO-dependent mechanisms such as gating of the potassium (K+) channel. This hypothesis was further investigated using the K+ channel blocker, glybenclamide. Following intraperitoneal injection of 4.5 mg/kg glybenclamide or saline, the jejunum of anesthetized rats was perfused with a standard oral rehydration solution in the presence or absence of 2.5 g/L gum arabic, as well as 1 mmol/L l-arginine to enhance NO production. Sodium, net water, and glucose absorption and unidirectional water movement were determined. Gum arabic showed regulatory capacity for NO-dependent metabolism by reducing net water absorption in the absence of arginine, and sodium absorption after arginine stimulation, in the absence of glybenclamide. Addition of gum arabic to oral rehydration solution, in glybenclamide pretreated animals, and in the absence of arginine, normalized sodium absorption, but was less effective in restoring net water transport. Injection of glybenclamide sharply decreased all absorption markers in arginine supplemented oral rehydration solution, which were at least partially restored by addition of gum arabic to the oral rehydration solution. In the presence of glybenclamide, the effects of arginine became antiabsorptive, as had those observed in preceding studies with high arginine concentration. Gum arabic partially or fully reversed alterations produced by perfused 1 mmol/L arginine. Some of the effects of gum arabic on the small intestine are likely caused by its ability to remove NO as it diffuses into the lumen, thus reducing NO concentration in the enterocyte and indirectly affecting the absorptive/secretory response of the gut, which leads to normalization of absorptive function. These findings are consistent with the previously shown gum arabic-scavenging properties of NO and support a potential therapeutic role for this product.
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To investigate the efficacy of the ingestion of vinegar in aiding recovery from fatigue, we examined the effect of dietary acetic acid, the main component of vinegar, on glycogen repletion in rats. Rats were allowed access to a commercial diet twice daily for 6 d. After 15 h of food deprivation, they were either killed immediately or given 2 g of a diet containing 0 (control), 0.1, 0.2 or 0.4 g acetic acid/100 g diet for 2 h. The 0.2 g acetic acid group had significantly greater liver and gastrocnemius muscle glycogen concentration than the control group (P < 0.05). The concentrations of citrate in this group in both the liver and skeletal muscles were >1.3-fold greater than in the control group (P > 0.1). In liver, the concentration of xylulose-5-phosphate in the control group was significantly higher than in the 0.2 and 0.4 g acetic acid groups (P < 0.01). In gastrocnemius muscle, the concentration of glucose-6-phosphate in the control group was significantly lower and the ratio of fructose-1,6-bisphosphate/fructose-6-phosphate was significantly higher than in the 0.2 g acetic acid group (P < 0.05). This ratio in the soleus muscle of the acetic acid fed groups was <0.8-fold that of the control group (P > 0.1). In liver, acetic acid may activate gluconeogenesis and inactivate glycolysis through inactivation of fructose-2,6-bisphosphate synthesis due to suppression of xylulose-5-phosphate accumulation. In skeletal muscle, acetic acid may inhibit glycolysis by suppression of phosphofructokinase-1 activity. We conclude that a diet containing acetic acid may enhance glycogen repletion in liver and skeletal muscle.
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To clarify the possibility of a preventive effect of dietary vinegar on blood pressure, long-term administration of vinegar or the acetic acid to SHR was examined. As a result, it was observed that acetic acid itself, the main component of vinegar, significantly reduced both blood pressure (p<0.05) and renin activity (p<0.01) compared to controls given no acetic acid or vinegar, as well as vinegar. There were no significant differences in angiotensin I-converting enzyme activity in various organs. As for the mechanism of this function, it was suggested that this reduction in blood pressure may be caused by the significant reduction in renin activity and the subsequent decrease in angiotensin II. From this study, it was also suggested that the antihypertensive effect of vinegar is mainly due to the acetic acid in it.
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It has been found that commercial water-soluble soybean polysaccharides (SSPS) can make cooked rice and noodles non-sticky and prevent rice grains and noodles from adhering to each other. We studied in detail the phenomenon of rice cooked with SSPS. We assumed that the phenomenon resulted from the interaction between SSPS and starch during cooking, and studied the effects of SSPS on the gelatinizing behavior of rice starch by using a Rapid-Visco-Analyzer. The addition of SSPS reduced the viscosity of the gelatinized starch. This lower final viscosity of the rice starch was more distinct from than that of potato starch. These results imply that the properties of SSPS in forming a non-sticky condition might result from a decrease in the viscosity of the gelatinized starch.
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The objectives were to examine the feasibility of using white rice as a reference food in the study of glycemic index (GI) and to examine the GI values of both single and mixed meal foods among rice species, processed rice products, beans, and dairy products. Subjects were served with 50 g carbohydrate content of white rice at least two times (maximum three times) and test food once after separate overnight fasts. Capillary blood glucose measurements were carried out before and during 120 min after each food load. The study was carried out in an outpatient setting. A total of 58 (38 females and 20 males) nondiseased subjects, mean aged 37 y and mean BMI 22 kg/m(2) were included. The correlation between incremental area under curve of white rice and glucose was r=0.853 (n=10, P <0.0001) and white rice was considered suitable to be used as a reference food. Among mixed meal foods, the combination of carbohydrate foods with vinegar, dairy products, and bean products significantly decreased the GI value of white rice of 20-40%. The reduction of GI occurred whether the foods were taken together, before or after rice intake. GI of noodles such as udon, soba, and spaghetti showed low GI values. White rice could be used as a reference food in determining GI values of foods. A total of 32 single and mixed meal Japanese common food products were examined for their GI values.
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This paper presents a review of the industrially most relevant exudate gums: gum arabic, gum karya, and gum tragacanth. Exudate gums are obtained as the natural exudates of different tree species and exhibit unique properties in a wide variety of applications. This review covers the chemical structure, occurrence and production of the different gums. It also deals with the size and relative importance of the various players on the world market. Furthermore, it gives an overview of the main application fields of the different gums, both food and non-food.
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Overdose of acetaminophen, a widely used analgesic drug, can result in severe hepatotoxicity and is often fatal. This study was undertaken to examine the effects of arabic gum (AG), which is commonly used in processed foods, on acetaminophen-induced hepatotoxicity in mice. Mice were given arabic gum orally (100 g l(-1)) 5 days before a hepatotoxic dose of acetaminophen (500 mg kg(-1)) intraperitoneally. Arabic gum administration dramatically reduced acetaminophen-induced hepatotoxicity as evidenced by reduced serum alanine (ALT) and aspartate aminotransferase (AST) activities. Acetaminophen-induced hepatic lipid peroxidation was reduced significantly by arabic gum pretreatment. The protection offered by arabic gum does not appear to be caused by a decrease in the formation of toxic acetaminophen metabolites, which consumes glutathione, because arabic gum did not alter acetaminophen-induced hepatic glutathione depletion. Acetaminophen increased nitric oxide synthesis as measured by serum nitrate plus nitrite at 4 and 6 h after administration and arabic gum pretreatment significantly reduced their formation. In conclusion, arabic gum is effective in protecting mice against acetaminophen-induced hepatotoxicity. This protection may involve the reduction of oxidative stress.
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In this study, we carried out toxicogenomic analysis using in-house cDNA microarray to ascertain the long-term effects of neonatal exposure to genistein, also known as phytoestrogen, on testicular gene expression in mice. Male ICR mice, 1 day after birth, were exposed for 5 days to genistein (1000 microg/mouse/day) or diethylstilbestrol (DES) (50 microg/mouse/day), used as an example of a potent estrogen, and their testes were used when they were 12 weeks old. Since exposure to DES was been reported to induce morphological changes and alteration of gene expression in reproductive organs, DES was used as a positive control. Genistein-treated mice did not show any histological abnormalities or increased apoptotic cells in testes, but these abnormalities and increases were found in DES-treated mice. On the other hand, mRNA expression analysis using in-house cDNA microarray revealed that 2 down-regulated genes (GeneBank accession No. W49392 and AI430907) were detected in genistein-treated mouse testes. Moreover, real-time PCR analysis revealed that mRNAs of the W49392 gene, estrogen receptor alpha (ERalpha) and androgen receptor (AR), were down-regulated in the testes of both genistein-treated and DES-treated mice. In our present study using toxicogenomic analysis, long-term alteration in testicular mRNA expression, without morphological change in testes, was detected after neonatal treatment with genistein, indicating that the W49392 gene, in addition to ERalpha and AR, might be useful as a biological marker for predicting the effects of neonatal exposure to DES and genistein.
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To find out whether the expressions of these adipocyte markers are influenced by oriental medicine, obesity rats induced by high fat diet (HFD) for 8 weeks were injected with 50 mg/100 g body weight adlay seed crude extract (ACE), daily for 4 weeks. The results are summarized as follows: HFD + ACE group significantly reduced food intakes and body weights. Weights of epididymal and peritoneal fat were dramatically increased in HFD groups compared with those of normal diet (ND) group but significantly decreased more in HFD + ACE group than those of HFD + saline group (sham). Those of brown adipocytes were increased in HFD + ACE group compared to ND and sham groups but there was no significant difference. The sizes in white adipose tissue (WAT) by microscope were markedly larger in HFD groups than ND group but considerably reduced in HFD + ACE group compared with sham group. The levels of triglyceride, total-cholesterol and leptin in blood serum were significantly decreased in HFD + ACE group compared to those of sham group. Leptin and TNF-alpha mRNA expressions in WAT of rats were remarkably increased more in sham group than in those of ND group. Those of HFD + ACE group were significantly decreased compared with those of sham group, especially. TNF-alpha mRNA expression in HFD + ACE group was declined more than that of ND group. In conclusion, treatments of ACE modulated expressions of leptin and TNF-alpha and reduced body weights, food intake, fat size, adipose tissue mass and serum hyperlipidemia in obesity rat fed HFD. Accordingly, the oriental medicine extract, adlay seed crude extract, can be considered for obesity therapies controlling.
Article
The objective of this study is to examine the glycemic response to common Chinese foods in patients with type 2 diabetes. Twenty-four Chinese adults with type 2 diabetes participated. Subjects were allocated to eat a pair of test meals in random order. Test meals included plain porridge with lean pork (meal 1A), plain porridge and Shrimp Shao Mai (Doll Brand, Winner Food Products Limited, Hong Kong) (meal 1B), boiled rice with boiled egg white (meal 2A), fried rice with whole egg (meal 2B), plain noodles in clear soup (meal 3A), and Pickled Vegetable and Pork-flavored Instant Bowl Noodles (Doll Brand, Winner Food Products Limited) (meal 3B). Nutritional content of the meals was calculated from the nutritional label on the food package and the food composition table. Plasma glucose was checked before the meal and in 30-minute intervals for up to 4 hours after the meal. Significant differences in the area under the curve of glucose up to 2 hours after the meal were detected between meal 1A and 2A ( P =.044), 1A and 3A ( P =.001), and 3A and 3B ( P =.017). The results suggest that fat alone does not alter the glycemic response to rice or porridge. Porridge produces a higher glycemic response than rice and noodles despite similar carbohydrate contents, and different noodles lead to differences in glycemic excursion, suggesting that the glycemic index of common Chinese foods is affected by cooking methods and food processing.
Article
The fermentation of three arabinoxylan (AX) fractions from wheat by the human fecal microflora was investigated in vitro. Three AX fractions, with average molecular masses of 354, 278, and 66 kDa, were incorporated into miniature-scale batch cultures (with inulin as a positive prebiotic control) with feces from three healthy donors, aged 23-29. Microflora changes were monitored by the culture-independent technique, fluorescent in situ hybridization, and short chain fatty acid (SCFA) and lactic acid production were measured by high-performance liquid chromatography. Total cell numbers increased significantly in all treated cultures, and the fermentation of AX was associated with a proliferation of the bifidobacteria, lactobacilli, and eubacteria groups. Smaller but statistically significant increases in bacteroides and clostridia groups were also observed. All AX fractions had comparable bifidogenic impacts on the microflora at 5 and 12 h, but the 66 kDa AX was particularly selective for lactobacilli. Eubacteria increased significantly on all AX fractions, particularly on 66 kDa AX. As previously reported, inulin gave a selective increase in bifidobacteria. All supplemented cultures showed significant rises in total SCFA production, with a particularly high proportion of butyric acid being produced from AX fermentation. The prebiotic effect, that is, the selectivity of AX for bifidobacteria and lactobacilli groups, increased as the molecular mass of the AX decreased. This suggests that molecular mass may influence the fermentation of AX in the colon.
Component analysis of coix seeds
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The effects of G.A. oral treatment on the metabolic profile of chronic renal failure patients under regular haemodialysis in Central Sudan Breakfast, blood glucose and memory Postprandial glucose response to Chinese foods in patients with type 2 diabetes
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Degradation of high-methoxyl pectin by dynamic high pressure microfluidization and its mechanism
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