Treatment of diabetes with guar gum. Reduction of urinary glucose loss in diabetics

Synthesis, characterization and evaluation of in vitro antimicrobial and anti-diabetic activity of berberine encapsulated in guar-acacia gum nanocomplexes

In the present study, the anti-diabetic and antimicrobial properties of berberine were improved using non-ionic guar gum and ionic acacia gum as nanocarriers. Berberine loaded guar-acacia gum nanocomplexes were synthesized by employing ionic complexation method. The formulation was characterized by dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM) and evaluated for in vitro dissolution study, anti-diabetic activity and antimicrobial activity. The optimized berberine loaded guar-acacia gum nanocomplexes had a particle size of 290.2 nm as indicated by DLS and drug entrapment efficiency of 96.5%. Morphological analysis revealed that berberine nanocomplexes were spherical-shaped with a smooth surface and size in the range of 100–250 nm. Moreover, berberine loaded guar-acacia nanocomplexes showed good stability and controlled released property in vitro. Antimicrobial activity against bacterial strains and fungal strains demonstrated the higher antimicrobial potential of berberine loaded gum nanocomplexes than gum nanocomplexes (blank) and pure berberine as indicated by the greater zone of inhibition diameter. In vitro anti-diabetic assessment showed higher percentage inhibition of the α-amylase enzyme by berberine loaded gum nanocomplexes as compared to pure berberine and blank nanocomplexes. In conclusion, the improved biological potency of berberine upon encapsulation into gum nanocomplexes indicates that berberine loaded guar-acacia gum nanocomplexes can be used as a promising candidate against diabetes and pathogenic microorganisms in the near future.

Guar (Cyamopsis tetragonoloba L.) plant gum: From biological applications to advanced nanomedicine

Natural polymers are an efficient class of eco-friendly and biodegradable polymers, because they are readily available, come from natural sources, inexpensive and can be chemically modified with the correct reagents. Guar gum (GG) is a natural polymer with great potential to be used in pharmaceutical formulations due to its unique composition and lack of toxicity. GG can be designed to suit the needs of the biological and medical engineering sectors. In the development of innovative drug delivery systems, GG is commonly utilized as a rate-controlling excipient. In this review, different properties of GG including chemical composition, extraction methods and its usefulness in diabetes, cholesterol lowering, weight control, tablet formulations as well as its food application were discussed. The other purpose of this study is to evaluate potential use of GG and its derivatives for advanced nanomedicine such as drug delivery, tissue engineering and nanosensing. It should be noted that some applicable patents in medical area have also been included in the rest of this survey to extend knowledge about guar gum and its polymeric nature.

Targeting Carbohydrates and Polyphenols for a Healthy Microbiome and Healthy Weight

Purpose of Review

In this review, we focus on microbiota modulation using non-digestible carbohydrate and polyphenols (i.e., prebiotics) that have the potential to modulate body weight.

Recent Findings

Prebiotics derived from plants have gained the interest of public and scientific communities as they may prevent diseases and help maintain health.

Summary

Maintaining a healthy body weight is key to reducing the risk of developing chronic metabolic complications. However, the prevalence of obesity has increased to pandemic proportions and is now ranked globally in the top five risk factors for death. While diet and behavioral modification programs aiming to reduce weight gain and promote weight loss are effective in the short term, they remain insufficient over the long haul as compliance is often low and weight regain is very common. As a result, novel dietary strategies targeting the gut microbiota have been successful in decreasing obesity and metabolic disorders via different molecular mechanisms.

The Gut Microbiome Influences Host Endocrine Functions

The gut microbiome is considered an organ contributing to the regulation of host metabolism. Since the relationship between the gut microbiome and specific diseases was elucidated, numerous studies have deciphered molecular mechanisms explaining how gut bacteria interact with host cells and eventually shape metabolism. Both metagenomic and metabolomic analyses have contributed to the discovery of bacterial-derived metabolites acting on host cells. In this review, we examine the molecular mechanisms by which bacterial metabolites act as paracrine or endocrine factors, thereby regulating host metabolism. We highlight the impact of specific short-chain fatty acids on the secretion of gut peptides (i.e., glucagon-like peptide-1, peptide YY) and other metabolites produced from different amino acids and regulating inflammation, glucose metabolism, or energy homeostasis. We also discuss the role of gut microbes on the regulation of bioactive lipids that belong to the endocannabinoid system and specific neurotransmitters (e.g., γ-aminobutyric acid, serotonin, nitric oxide). Finally, we review the role of specific bacterial components (i.e., ClpB, Amuc_1100) also acting as endocrine factors and eventually controlling host metabolism. In conclusion, this review summarizes the recent state of the art, aiming at providing evidence that the gut microbiome influences host endocrine functions via several bacteria-derived metabolites.

Guar gum as a promising starting material for diverse applications: A review

Guar gum is the powdered endosperm of the seeds of the Cyamopsis tetragonolobus which is a leguminous crop. The endosperm contains a complex polysaccharide called galactomannan, which is a polymer of d-galactose and d-mannose. This hydroxyl group rich polymer when added to water forms hydrogen bonding imparting significant viscosity and thickening to the solution. Due to its thickening, emulsifying, binding and gelling properties, quick solubility in cold water, wide pH stability, film forming ability and biodegradability, it finds applications in large number of industries. In last few decades a lot of research has been done on guar gum to fit it into particular application, as such or by its structural modifications. This review gives an overview of the nature, chemistry and properties of guar gum and discusses recent developments in its modifications and applications in major industries like hydraulic fracturing, explosives, food, agriculture, textile, paper, cosmetics, bioremediation, drug delivery, medical and pharmaceuticals. This article would help researchers engaged in biopolymer area and other end-users who want to begin research in natural polysaccharides.

Food structure is critical for optimal health

Much nutrition policy is nutrient-based, supported by nutrient science, food nutrient composition tables and dietary nutrient recommendations, but not by reference to food structure.

Effect of different kinds of fibre on postprandial blood glucose in insulin-dependent diabetics

Dietary fibre may retard glucose absorption in normal and diabetic subjects. It is, however, unclear which type of fibre would be most suitable for this purpose. We therefore studied whether pectin differs from fibre from barley (85%) and citrus (15%) (Dumovital) in its effect on postprandial blood glucose responses. Eight insulin-dependent diabetics fasted overnight and were then given a meal without their morning insulin. The basic meal, composed of 90 g white bread and 120 g jam (total carbohydrate 105 g), was given three times: alone, with 15 g pectin and with 15 g Dumovital fibre. Blood glucose was measured for three hours. The tests showed that pectin administration considerably inhibited the postprandial rise in blood glucose, while Dumovital showed no such effect. Barley/citrus fibre (a mixture of cellulose, hemicellulose, lignin and pectin) has not the same inhibiting effect on postprandial rise in blood glucose as pure pectin in insulin-dependent diabetics. Thus, the specific type of fibre must be considered when prescribing dietary fibre to diabetics.

Long-term Measurement of Gastric Motility using Passive Telemetry and Effect of Guar and Cellulose as Food Additives in Dogs

The suitability of passive telemetry for long-term measurements of gastric motility in two groups of dogs with different body weights, four Beagles and four Labrador Retrievers, was investigated. An intra-abdominal measuring device, with a pressure sensor and electrodes within the gastric wall, allowed the continuous recording of the intensity and frequency of contractions simultaneously with an electromyogram (EMG). In fasting dogs a typical inter-digestive motility cycle was reproducible. Within 15 min of feeding the integral of the pressure curve increased significantly, reaching its maximum 30-45 min post-prandially. The peak frequency also significantly increased immediately after feeding, reaching the maximum of 22 contractions per 5 min. The post-prandial motility patterns of the groups were significantly different. The pressure amplitudes of the Labradors were significantly higher and the peak frequencies significantly lower than the Beagles. The addition of guar to the food (2.5% or 5%) leads to a significant reduction of the intensity of the antral contractions, whereas the frequency was hardly affected. In comparison, the effect of cellulose, as a food additive (2.5% or 5%), was rather modest. The intensity of the post-prandial contractions, influenced by cellulose, was significantly increased in Beagles, but was decreased in Labradors. Passive telemetry has been proven to be a suitable method for the long-term investigation of the physiological gastric motility and the effect of food additives. The measuring device was still functional after removal 8 weeks later.

In vitro fermentation characteristics of a mixture of Raftilose and guar gum by human faecal bacteria

BACKGROUND

The therapeutic effects of indigestible carbohydrates in the human colon are well known. Most fermentation studies have examined only single carbohydrates. Considering the idiosyncratic actions of individual carbohydrates and the dose required, it is unlikely that any one carbohydrate will provide ideal physiological actions without having some undesirable effects. Little is known of how mixing non-digestible carbohydrates affects their fermentation. This necessitates fermentation studies using different carbohydrates in mixtures.

AIM OF THE STUDY

The aim of this study was to test the effect of mixing Raftilose (R) and guar gum (G) on short chain fatty acid (SCFA) production in in vitro cultures of human faecal bacteria.

METHOD

The fermentation of the individual carbohydrates (10 mg/ml) was compared with that of a 50:50 mixture in anaerobic in vitro cultures of human faeces.

RESULTS

Cultures of R/G mixtures produced significantly more n-butyrate than 100 mg G alone at 8 and 24 hours (p < 0.02). There was no significant difference in the production of n-butyrate between cultures of 100 mg R and the R/G mixture at 8 and 24 hours. R (100 mg) produced a propionic/butyric (p/b) acid ratio of 1.18 compared with 3.88 for 100 mg G, whereas R/G mixture produced a p/b ratio of 2.01.

CONCLUSION

The fermentation of R/G mixture was different compared with 100 mg of R or G alone. There was no loss of n-butyrate in the culture containing R/G (50 mg of each) mixture compared with the 100 mg R culture.

Effect of wheat bran on glycemic control and risk factors for cardiovascular disease in type 2 diabetes

OBJECTIVE

Cohort studies indicate that cereal fiber reduces the risk of diabetes and coronary heart disease (CHD). Therefore, we assessed the effect of wheat bran on glycemic control and CHD risk factors in type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 23 subjects with type 2 diabetes (16 men and 7 postmenopausal women) completed two 3-month phases of a randomized crossover study. In the test phase, bread and breakfast cereals were provided as products high in cereal fiber (19 g/day additional cereal fiber). In the control phase, supplements were low in fiber (4 g/day additional cereal fiber).

RESULTS

Between the test and control treatments, no differences were seen in body weight, fasting blood glucose, HbA(1c), serum lipids, apolipoproteins, blood pressure, serum uric acid, clotting factors, homocysteine, C-reactive protein, magnesium, calcium, iron, or ferritin. LDL oxidation in the test phase was higher than that seen in the control phase (12.1 +/- 5.4%, P < 0.034). Of the subjects originally recruited, more dropped out of the study for health and food preference reasons from the control phase (16 subjects) than the test phase (11 subjects).

CONCLUSIONS

High-fiber cereal foods did not improve conventional markers of glycemic control or risk factors for CHD in type 2 diabetes over 3 months. Possibly longer studies are required to demonstrate the benefits of cereal fiber. Alternatively, cereal fiber in the diet may be a marker for another component of whole grains that imparts health advantages or a healthy lifestyle.

No effects of high-fiber diets on metabolic control and insulin-sensitivity in type 1 diabetic subjects

The metabolic effects of a three-month treatment with a high-fiber diet (15 grams of guar-gum added to a standard diet) were investigated in seven type 1 diabetic subjects, with a moderately poor metabolic control. HbA1c levels, daily insulin requirement, cholesterol, triglyceride, amino acid and intermediate metabolite concentrations were evaluated before and following the high fiber diet, both in the postabsorptive state at euglycemia and during a euglycemic, hyperinsulinemic, hyperaminoacidemic clamp. Insulin-mediated glucose utilization, an index of insulin-sensitivity, was also measured during the clamp. Following the diet, no differences in HbA1c levels (7.6 +/- 0.7%----7.3 +/- 0.6%), daily insulin requirement (50 +/- 5----51 +/- 3 U/d), triglyceride, amino acid and intermediary metabolite concentrations in the basal, euglycemic state, were observed. Only cholesterol concentrations decreased significantly (from 165 +/- 12 to 142 +/- 12 mg/dl, P less than 0.01) after the diet. During the clamp, the concentrations of all measured substrates were comparable before and after high fiber treatment. Insulin-mediated glucose disposal was also unchanged by guar-gum treatment. Patients' body weights were not modified by the diet. In conclusion, our study shows that a high fiber diet, obtained with the addition of 15 grams of guar-gum to a standard diet, is of no benefit to IDDM either as regards the metabolic control or insulin sensitivity. Only cholesterol levels were decreased. Therefore, the costs and benefits of these diets in the treatment of IDDM should be reconsidered.

The effect of soluble- and insoluble-fibre supplementation on post-prandial glucose tolerance, insulin and gastric inhibitory polypeptide secretion in healthy subjects

Six healthy non-obese male subjects were given three test meals containing 100 g carbohydrate and 1.5 g soluble paracetamol, supplemented on one occasion with 10 g guar gum and on another with 10 g sugarbeet fiber. A further six subjects were given the same test meal supplemented on one occasion with 10 g soya-bean-cotyledon fibre and on another, 5 g glucomannan. Venous blood samples were taken before, and at intervals for 180 min following the meal, and analysed for insulin, gastric inhibitory polypeptide (GIP) and paracetamol (as an index of gastric emptying). Arterialized blood samples were taken and analysed for glucose. Meal supplementation with both guar gum and sugar-beet fibre improved glucose tolerance, but circulating glucose levels were unaffected by the addition of either soya-bean-cotyledon fibre or glucomannan to the meals. Supplementation with guar gum and glucomannan lowered post-prandial insulin levels. Insulin levels were enhanced by addition of soya-bean-cotyledon fibre to the meal and unaffected by sugar-beet fibre. Post-prandial GIP levels were lowered in the guar-gum-supplemented meal and augmented with sugar-beet fibre supplementation. Addition of glucomannan and soya-bean-cotyledon fibre did not affect circulating GIP levels. The study failed to confirm previous reports of improved glucose tolerance following glucomannan and soya-bean-cotyledon fibre supplementation. The failure of sugar-beet fibre to reduce post-prandial insulin secretion despite improved glucose tolerance may be due to the observed increased secretion of GIP. The increased insulin levels seen following soya-bean-cotyledon fibre supplementation cannot be attributed either to changes in glucose tolerance, GIP secretion or gastric emptying.(ABSTRACT TRUNCATED AT 250 WORDS)

The medium-term effect of natural or extractive dietary fibres on plasma amino acids and lipids in type 1 diabetics

We evaluated the effect of a diet rich in natural (NF) or extractive fibres (guar gum) on 12 male IDD (insulin-dependent diabetes) out-patients. The treatment lasted for 2 months. During the first month the patients were on an isocaloric diet containing 30 g of fibres and then they were randomly subdivided into two groups. One group followed an isocaloric diet rich in fibres (70 g/day), the second group an isocaloric diet enriched by guar (9 g of guar added to 30 g of natural fibres/day). Reduced serum levels of HbA1c and several amino acids showed that metabolic control significantly improved under each dietary regimen.

Glucose and insulin response in diabetic subjects: acute effect of carbohydrate level and the addition of soy polysaccharide in defined-formula diets

This single-meal pilot study compared the plasma glucose and serum insulin response to defined-formula diets with two levels of carbohydrate (CHO) (55% and 30% of the kilocalories) with and without added soy polysaccharide (10 g) in subjects with type 2 diabetes mellitus. Subjects received each of the four liquid-formula test meals in a randomly assigned order: 1) high CHO, low fiber (HC, LF), 2) high CHO, high fiber (HC, HF), 3) low CHO, low fiber (LC, LF), and 4) low CHO, high fiber (LC, HF). On the day of each test meal the formula was consumed, eight blood samples were drawn for plasma glucose and serum insulin measurements, and a 4-h urine collection was obtained for measuring glucose excretion. Our results showed that area increments under glucose and insulin curves were significantly lower with both low-CHO formulas (p less than 0.001). The addition of soy polysaccharide to the liquid formula did not result in statistically different area increments for glucose or insulin.

Does adding fibre to a low energy, high carbohydrate, low fat diet confer any benefit to the management of newly diagnosed overweight type II diabetics?

The effect of supplementing a low energy (roughly 5.0 MJ), high carbohydrate (180 g), low fat (roughly 25 g) diet with 10-15 g of either cereal fibre or guar gum was investigated in 24 newly diagnosed overweight non-insulin-dependent (type II) diabetics. The patients were divided into three treatment groups: one received a low fibre control diet throughout the study period of 20 weeks and the other received two supplements of cereal fibre and guar gum in a crossover manner. The nutrient content of the diets was kept constant throughout. Though patients taking the low fibre diet showed a smaller reduction in fasting plasma glucose concentrations over the first eight weeks than patients taking a high fibre diet, this difference was not evident at the end of 20 weeks; reductions in weight and glycated haemoglobin values were similar for each dietary regimen throughout the trial. There was little evidence that supplementing a low energy, high carbohydrate diet with fibre confers any therapeutic benefit to type II diabetics and no evidence that taking fibre as viscous polysaccharides is any more beneficial to overweight diabetics than taking a similar fibre supplement as cereal. On the contrary, guar gum caused more abdominal discomfort and flatulence than the other diets.

Starchy foods and fiber: reduced rate of digestion and improved carbohydrate metabolism

The rate of the small intestine amylolytic digestion appears to be a major determinant of the glycemic response. Foods such as legumes appear to be digested less rapidly than many cereal foods although even amongst these large differences in rates of in vitro digestion exist. Studies of diabetes using high fibre, high legume diets have almost uniformly noted improvements in glycemic control and blood lipid profile. However, diets where changes in fibre content have been relatively small, but where the foods were selected on the basis of their slow rates of digestion and flatter glycemic response, have also produced similar beneficial effects. The reasons for the altered rates of digestion include fibre, food form, the nature of the starch, antinutrients etc. Through reducing the rate of digestion of starchy foods post prandially "slow release" starchy foods blunt many gut hormone responses, and prolong FFA and ketone body suppression. In addition increased starch losses to the colon may enhance production of SCFA. All these events may modify carbohydrate and lipid metabolism. Many foods which produce these effects are traditional starchy foods and so strengthen current recommendations of the diabetes association, heart foundations and cancer institutes to increase the use of starchy foods through reducing fat intake. Recognition of the nutritional value of these foods is however not new, but was well accepted in the ancient world and is still preserved in traditional cultures where freedom from many of the major non-infective Western diseases is a notable phenomenon.

Beneficial effects of palatable guar and guar plus fructose diets in diabetic children

This randomized cross-over study evaluates the effects of extended, guar and guar + fructose diets on the metabolic balance of children with insulin-dependent diabetes mellitus (IDDM). We studied 22 children; mean age 12.2 years, mean duration of diabetes 4.4 years. The diet was supplement for three weeks with guar in palatable form (5% of daily carbohydrate intake) and with guar + fructose (1 g of fructose/kg body weight, max 30 g/d) for another three weeks. A control group (8 children, mean age 12.3, duration of diabetes 4.3 years) followed the same experimental protocol without guar supplementation. The metabolic balance was assessed by glucosuria index (per cent of tests with less than 1% glucosuria from all urine tests) and measurements of red cell glycohaemoglobin A1c (HbA1c). Serum total and HDL-cholesterol, C-peptide, pancreatic and enteroglucagon were also measured. HbA1c decreased during guar (p less than 0.001) and guar + fructose diet (p less than 0.001). The glucosuria index improved (p less than 0.02) and the serum total cholesterol concentration decreased (p less than 0.02) during the experimental guar diets. Guar in acceptable form and quantity in the diet appears to improve metabolic control of diabetic children.

The degradation of guar gum by a faecal incubation system

1. Homogenized and diluted faeces (50 g/l) from one human source were incubated with the complex plant polysaccharide, guar gum, to investigate the degradation of viscous polysaccharides by intestinal bacteria. 2. Incubation of the faecal homogenate with guar gum produced a rapid decrease in viscosity and in pH, accompanied by the release of hydrogen. 3. No changes in viscosity or pH were observed and there was no production of H2 gas when guar gum was incubated with autoclaved faecal homogenate (20 min, 1.03 x 10(5) Pa). 4. A bacteria-free filtrate of faeces was prepared by centrifuging the faecal homogenate (2400 g for 100 min) followed by filtration through a Seitz filter and then a millipore filter (size 0.45 micron). Incubating this with guar gum produced a slow decrease in viscosity, but no significant change in pH and no generation of H2. 5. Our results show that guar gum can be fermented by human colonic bacteria and suggest the possibility of predigestion by extracellular free enzymes.

Diabetic control is improved by guar gum and wheat bran supplementation

Twenty-eight insulin-dependent diabetics were treated with different dietary regimes for three periods of three months. Initially they used a white flour bread (run-in period), then their daily bread ration was enriched with guar gum (mean dose: 29 g), and then with wheat bran (mean dose: 33 g) in a randomized crossover pattern. Fasting and postprandial blood glucose levels were measured on filter paper spots collected once weekly at home, and other biochemical values were measured monthly. No improvement in diabetic control was seen during the run-in period. Mean postprandial blood glucose decreased from 12.0 +/- 3.8 mmol/l (mean +/- SD) in the run-in period to 9.7 +/- 2.8 mmol/l (p less than 0.01) in the guar period and to 9.7 +/- mmol/l (p less than 0.01) in the bran period. HbA1 decreased from 10.5 +/- 2.1% in the run-in period to 9.7 +/- 1.6% (less than 0.05) at the end of the guar period and 9.9 +/- 1.2% (not significant) at the end of the bran period. Only modest changes were seen in serum-lipids--total cholesterol decreased significantly in the guar period, but not in the bran period. In this study both guar gum and wheat bran were well tolerated and produced a substantial decrease in postprandial blood glucose.

Dietary survey of diabetics

This study of 168 diabetic children from Tyneside and Teeside aimed to record what the children actually ate and to compare this with both their prescribed diet and current recommendations. The amounts of energy consumed were similar to those expected of non-diabetic children, but the components of the diabetic children's diets were different, consisting of more fat and fibre, but less sugars and carbohydrates. They ate more carbohydrate than prescribed but less than current recommendations as there was a shortfall between the amount prescribed and that suggested in the recommendations. Diabetic control was related to the amount of fibre consumed and to compliance with the prescribed diet, but not to the proportion of energy taken as carbohydrate. The insulin dose was slightly lower in those children eating more fibre.

Diabetic Chinese hamsters: metabolic effects of long term guar gum consumption

The effect of 13 weeks of guar gum or cellulose diet consumption upon metabolic parameters was examined in diabetic and control adult Chinese hamsters. Diabetic hamsters displayed typical diabetic metabolic profiles. Both 8% guar gum and 8% cellulose diets maintained body weights in all 4 groups during the study. Diabetic and control hamsters fed guar gum drank less water as the study progressed. At weeks 9 and 13, diabetic hamsters fed guar gum excreted less urine compared to those fed cellulose. Diabetic hamsters fed guar gum had reduced urinary glucose excretion at weeks 1, 9 and 13 compared to those fed cellulose. Control hamsters fed either diet had normal urine volumes with only traces of glucose. Similar fasting plasma glucose levels were measured initially for all diabetic hamsters; all 3 subsequent measurements revealed lower levels for the group fed guar gum. Control hamsters had normal fasting plasma glucose levels. Comparable fasting plasma insulin levels were measured for all diabetic hamsters; these levels increased during the study. Control hamster fasting plasma insulin levels were 3 times higher and did not change. Throughout the study, diabetic hamsters fed guar gum consistently had healthier metabolic profiles than those fed cellulose.

The effect of guar gum on carbohydrate-, fat- and protein-stimulated gut hormone secretion: modification of postprandial gastric inhibitory polypeptide and gastrin responses

The effect of incorporating guar gum into predominantly single-component meals of carbohydrate, fat or protein on liquid gastric emptying and on the secretion of gastric inhibitory polypeptide (GIP), gastrin and motilin, was studied in healthy human volunteers. Volunteers were given either 80 ml Hycal (carbohydrate meal), 150 g cooked lean minced beef (protein meal) or 200 ml double cream (fat meal) either with or without 5 or 6 g guar gum. Liquid gastric emptying was monitored in the fat and protein meals by taking 1.5 g paracetamol, consumed in water, with the meals and monitoring its appearance in circulation. Postprandial insulin and GIP levels were both significantly reduced by addition of guar gum to the carbohydrate meal. Postprandial GIP secretion was also reduced by addition of guar gum to the protein meal, but protein-stimulated gastrin secretion was enhanced by guar gum. There was a significant negative correlation between peak circulating gastrin levels and the corresponding GIP levels. Postprandial GIP secretion and plasma motilin levels were unaffected by addition of guar gum to the fat meal. 5 and 10 g guar gum/l solutions in water possessed buffering capacities between pH 2.75 and 5.5. Guar gum at 5 g/l caused no detectable change in liquid gastric-emptying time. The observed augmentation of gastrin secretion by guar gum following a protein meal could be due either to the buffering capacity of guar gum or to the attenuation of GIP secretion. It is possible that the chronic use of guar gum could be associated with changes in gastric acid secretion.

Glycaemic effects of bread and marmalade in insulin-dependent diabetes

The glycaemic responses of 12 C-peptide negative insulin-dependent diabetics were studied following four breakfasts with different carbohydrate sources. Total energy content of the meals was the usual for each subject, carbohydrate supplying 55% and fat 32%. The meals comprised: wholemeal bread with margarine; white bread with margarine; marmalade made with sucrose, and cheddar cheese; and marmalade (22% of total energy) on wholemeal bread with margarine. The study demonstrated powerfully that there were no statistically significant or clinically relevant differences between the meals in post-prandial glucose peak elevation, or in incremental area under the blood glucose curve to 120 mins. On these grounds, sucrose, in amounts considered acceptable to the general population, need not be prohibited from diabetic diets.

Effect of guar gum on gastric emptying after gastric resection

Gastric emptying after a conventional semisolid meal containing 5 g of guar gum granules or placebo was measured in a double-blind, controlled trial, using a radioisotopic (technetium Tc-99m DTPA) technique, in 11 patients who had undergone gastric resection, and who were experiencing the dumping syndrome. Guar gum clearly slowed gastric emptying in five of the 11 patients, and the results suggest that the addition of guar gum to normal meals, especially those rich in monosaccharides or disaccharides, may be helpful to post-gastrectomy patients suffering from the dumping syndrome.

Effect of brown rice and soybean dietary fiber on the control of glucose and lipid metabolism in diabetic rats

We have studied the effect of brown rice and soybean dietary fiber on the oral glucose tolerance test, plasma-insulin, -glucagon, -triglycerides, and cholesterol levels in control and streptozotocin-induced diabetic rats. Plasma glucose level after glucose loading in diabetic rats fed soybean fiber was considerably lower (60 and 120 min) than the corresponding group not receiving the fiber. Soybean fiber given to control rats decreased the plasma glucose at 60 min after the oral glucose test. Rice fiber decreased the plasma glucose of diabetic rats only at 60 min and the control rats fed with or without fiber elicited a comparable glycemic response. While soybean fiber significantly lowered the glucagon and triglyceride levels in both control and diabetic rats, rice fiber had no effect on these blood parameters. In conclusion, this study demonstrated the potential benefit of soybean dietary fiber over rice fiber in diabetes treatment with additional advantages resulting from its ease in usage either in a mixture of water or milk products and cooking. As well, being devoid of a disagreeable taste so characteristic of other fibers, patient acceptance is more forthcoming.

Efficacy of guar gum in preventing the dumping syndrome

The occurrence of dumping symptoms during 1 wk of use of 5 g of guar gum or placebo in meals was examined in a double-blind study in 11 patients, who had undergone gastric resection and were suffering from the dumping syndrome. The results show that guar gum prevented the dumping syndrome and increased tolerance to foods not previously tolerated in nine of the 11 patients.

The glycaemic index of foods tested in diabetic patients: a new basis for carbohydrate exchange favouring the use of legumes

Recently diabetic patients have been encouraged to increase their carbohydrate intake, but exact details of which foods to use are lacking. To determine whether sufficiently large differences existed to justify more specific dietary advice, we compared the glycaemic responses to 50 g carbohydrate portions of different foods, taken as breakfast test meals by groups of five to seven diabetic patients. Two- to threefold differences were seen amongst the 15 foods tested. The glycaemic responses for spaghetti, 'All-bran', rice and beans were significantly below those for bread, while 'Cornflakes' were above. Factors predicted to influence this were without effect, including: substituting wholemeal for white bread, increasing substantially the simple sugars (using 'All-bran' or bananas instead of wholemeal bread) and doubling meal protein by adding cottage cheese to bread. Paired comparisons of the glycaemic response to the five legumes with those of the seven other starchy foods (breads, spaghetti, rice, Cornflakes, oatmeal porridge and potatoes) showed that the mean peak rise in blood glucose concentration and mean area under the glucose curve after beans were 23 and 28% lower, respectively, than the mean for the other foods (p less than 0.001). Such results suggest a potentially valuable role for dried leguminous seeds in carbohydrate exchanges for individuals with impaired carbohydrate tolerance. These large differences in blood glucose response to different food cannot at present be predicted directly from tables of chemical composition. Nevertheless, physiological testing may both aid in understanding the factors responsible and help selection of the appropriate carbohydrate foods for the diabetic diet.