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1.
J Pediatr Gastroenterol Nutr ; 43(4): 459-69, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17033520

RESUMO

OBJECTIVES: Enterotoxigenic Escherichia coli (ETEC) infection is a major cause of dehydrating diarrhoea in infants and early-weaned piglets living under subhygienic conditions. We studied the effect of different tea types and subfractions on the intestinal fluid and electrolyte losses involved in ETEC diarrhoea. MATERIALS AND METHODS: Jejunal segments of anaesthetised piglets were infected with ETEC or ETEC heat-labile toxin (LT) and subsequently perfused for 8 hours with control or tea solutions containing green or black tea extract (BTE) or 3 different BTE subfractions containing small-size, large-size or no phenolics. Changes in intestinal fluid and electrolyte net absorption were measured. To assess the antisecretory effects of tea, BTE was incubated before or after administration of the secretagogue forskolin in rat jejunal tissue placed in Ussing chambers and Cl- secretion measured as changes in short-circuit current (I(SC)). RESULTS: Enterotoxigenic E. coli infection of piglet jejunal segments significantly reduced net absorption of fluid, Na+ and Cl- and increased net secretion of K+ compared with controls. Perfusion of the ETEC-infected segments with both 3 g/L green tea extract and BTE significantly inhibited these disturbances in fluid and electrolyte balance. The BTE subfraction rich in polymeric phenolics but not the other subfractions improved the fluid and electrolyte balance. Addition of forskolin to rat jejunal tissue induced a significant increase in I(SC). Pretreating but not posttreating the jejunal tissue with BTE inhibited the forskolin-induced increase in I(SC). CONCLUSIONS: Tea may inhibit net fluid and electrolyte losses involved in secretory diarrhoea from ETEC.


Assuntos
Disenteria/tratamento farmacológico , Infecções por Escherichia coli/tratamento farmacológico , Absorção Intestinal/efeitos dos fármacos , Jejuno/efeitos dos fármacos , Chá , Animais , Líquidos Corporais , Colforsina/farmacologia , Desidratação/etiologia , Modelos Animais de Doenças , Disenteria/microbiologia , Eletrólitos , Infecções por Escherichia coli/complicações , Feminino , Flavonoides/farmacologia , Fármacos Gastrointestinais/farmacologia , Técnicas In Vitro , Jejuno/metabolismo , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley , Suínos
2.
J Chromatogr B Biomed Sci Appl ; 760(2): 271-9, 2001 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-11530986

RESUMO

A HPLC-MS procedure for the sensitive and specific analysis of the black tea flavonoid theaflavin in human plasma and urine was developed. Levels were measured after enzymatic deconjugation, extraction into ethyl acetate, and separation by HPLC, using tandem mass spectrometry as a detecting system. Two healthy volunteers consumed 700 mg theaflavins, equivalent to about 30 cups of black tea. The maximum concentration detected in blood plasma was 1.0 microg l(-1) in a sample collected after 2 h. The concentration in urine also peaked after 2 h at 4.2 microg l(-1). Hence, only minute amounts of theaflavins can be detected in plasma and urine samples of healthy volunteers after ingestion.


Assuntos
Biflavonoides , Catequina , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Adulto , Feminino , Humanos , Masculino , Sensibilidade e Especificidade , Chá
3.
Xenobiotica ; 31(12): 891-901, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11780763

RESUMO

1. Ten healthy volunteers ingested 1.5 mmole epicatechin gallate (ECg), epigallocatechin (EGC) or epigallocatechin gallate (EGCg) in a randomized crossover design. After deconjugation, catechins in plasma and 24-h urine samples were determined by high-performance liquid chromatography (HPLC). Antioxidant activity was measured in plasma by determining ferric reducing activity (FRAP). 2. The catechin levels in plasma after ingestion were significantly different: EGC rose quickly with a short elimination half-life (t1/2 elim = 1.7 h), ECg was intermediate in rise but slowest in decline (t1/2 elim = 6.9h), EGCg was slowest in rise but intermediate in decline (t1/2 elim = 3.9h). At 24h, EGC and EGCg had returned to base levels, but ECg was still elevated. Peak maximum varied between 1.3 (EGCg) and 5.0 micromol l(-1) (EGC). 3. Very limited interconversion (ECg-->epicatechin, EGCg-->EGC) occurred indicating that degallation is not required for uptake. 4. Up to 13.6% of the ingested EGC (partly methylated) was excreted in the urine, but ECg or EGCg were not detected. 5. EGC and ECg produced an increase in antioxidant activity in plasma, but with EGCg, no statistically significant effect was found. 6. The pattern of uric acid in plasma showed a clear resemblance with that of FRAP and linear regression analysis indicated a very significant relationship (R2 = 0.88, p < 0.0001). 7. It is concluded that tea catechins differ significantly in their pharmacokinetic behaviour.


Assuntos
Catequina/análogos & derivados , Catequina/sangue , Administração Oral , Adolescente , Adulto , Idoso , Antioxidantes/metabolismo , Área Sob a Curva , Catequina/administração & dosagem , Catequina/urina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição Aleatória , Chá , Ácido Úrico/sangue
4.
Eur J Clin Nutr ; 54(2): 126-35, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10694783

RESUMO

BACKGROUND: High intakes of trans fatty acids (TFA) have been found to exert an undesirable effect on serum lipid profiles, and thus may increase the risk for cardiovascular disease. OBJECTIVES: Investigation of the association between TFA intake and serum lipids. DESIGN: Cross-sectional study in eight European countries (Finland, France, Greece, Iceland, The Netherlands, Portugal, Spain, Sweden) among 327 men and 299 women (50-65 y). Using a dietary history method, food consumption was assessed and TFA intake was calculated with recent figures on TFA levels of foods, collected in the TRANSFAIR study. RESULTS: Mean (+/-s.d.) TFA intake was 2.40+/-1.53 g/day for men and 1.98+/-1.49 g/day for women (0.87+/-0.48% and 0. 95+/-0.55% of energy, respectively), with the highest consumption in Iceland and the lowest in the Mediterranean countries. No associations were found between total TFA intake and LDL, HDL or LDL/HDL ratio after adjustment for cardiovascular risk factors. Additional adjustment for other fatty acid clusters resulted in a significant inverse trend between total TFA intake and total cholesterol (Ptrend<0.03). The most abundantly occurring TFA isomer, C18:1 t, contributed substantially to this inverse association. The TFA isomers C14:1 t9, C16:1 t9 and C22:1 t were not associated or were positively associated with LDL or total cholesterol. CONCLUSIONS: From this study we conclude that at the current European intake levels of trans fatty acids they are not associated with an unfavourable serum lipid profile. SPONSORSHIP: Unilever Research Laboratorium, the Dutch Dairy Foundation on Nutrition and Health, Cargill BV, the Institute of Food Research Norwich Laboratory, the Nutrition Branch of the Ministry of Agriculture, Fisheries and Food, the International Fishmeal and Oil Manufacturers' Association, Kraft Foods, NV Vandemoortele Coordination Center, Danone Group, McDonalds Deutschland Inc, Danish Veterinary and Food Administration, Valio Ltd, Raisio Group. European Journal of Clinical Nutrition (2000) 54, 126-135


Assuntos
Doenças Cardiovasculares/etiologia , Gorduras na Dieta/administração & dosagem , Ácidos Graxos/administração & dosagem , Tecido Adiposo/química , Idoso , Colesterol/sangue , Estudos Transversais , Registros de Dieta , Ingestão de Energia , Europa (Continente) , Ácidos Graxos/análise , Feminino , Humanos , Isomerismo , Modelos Lineares , Lipídeos/sangue , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Masculino , Pessoa de Meia-Idade , Fatores de Risco
5.
Eur J Clin Nutr ; 53(2): 143-57, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10099948

RESUMO

OBJECTIVE: To assess the intake of trans fatty acids (TFA) and other fatty acids in 14 Western European countries. DESIGN AND SUBJECTS: A maximum of 100 foods per country were sampled and centrally analysed. Each country calculated the intake of individual trans and other fatty acids, clusters of fatty acids and total fat in adults and/or the total population using the best available national food consumption data set. RESULTS: A wide variation was observed in the intake of total fat and (clusters) of fatty acids in absolute amounts. The variation in proportion of energy derived from total fat and from clusters of fatty acids was less. Only in Finland, Italy, Norway and Portugal total fat did provide on average less than 35% of energy intake. Saturated fatty acids (SFA) provided on average between 10% and 19% of total energy intake, with the lowest contribution in most Mediterranean countries. TFA intake ranged from 0.5% (Greece, Italy) to 2.1% (Iceland) of energy intake among men and from 0.8% (Greece) to 1.9% among women (Iceland) (1.2-6.7 g/d and 1.7-4.1 g/d, respectively). The TFA intake was lowest in Mediterranean countries (0.5-0.8 en%) but was also below 1% of energy in Finland and Germany. Moderate intakes were seen in Belgium, The Netherlands, Norway and UK and highest intake in Iceland. Trans isomers of C18:1 were the most TFA in the diet. Monounsaturated fatty acids contributed 9-12% of mean daily energy intake (except for Greece, nearly 18%) and polyunsaturated fatty acids 3-7%. CONCLUSION: The current intake of TFA in most Western European countries does not appear to be a reason for major concern. In several countries a considerable proportion of energy was derived from SFA. It would therefore be prudent to reduce intake of all cholesterol-raising fatty acids, TFA included.


Assuntos
Gorduras na Dieta/administração & dosagem , Ácidos Graxos/administração & dosagem , Adulto , Gorduras na Dieta/análise , Gorduras na Dieta/classificação , Ingestão de Energia , Europa (Continente) , Ácidos Graxos/análise , Ácidos Graxos/classificação , Feminino , Humanos , Masculino , Estereoisomerismo
6.
Br J Nutr ; 82(4): 309-17, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10655980

RESUMO

Effects of the conjugated linoleic acid (CLA) isomers cis-9, trans-11 (c9,t11 CLA) and trans-10, cis-12 (t10,c12 CLA) on lipid metabolism and markers of peroxisome proliferation were investigated in hamsters fed on purified diets containing 30% energy as fat and 0.1 g cholesterol/kg for 8 weeks. Four groups (n 32 each) received diets without CLA (control), with a mixture of equal amounts of c9,t11 and t10,c12 CLA (CLA mix), with c9,t11 CLA, and with t10,c12 CLA. The total amount of CLA isomers was 1.5% energy of 6.6g/ kg diet. CLA was incorporated into glycerides and exchanged for linoleic acid in the diet. Compared with the control, the CLA mix and t10,c12 CLA decreased fasting values of LDL- (21 and 18% respectively) and HDL-cholesterol (8 and 11%), increased VLDL-triacylglycerol (80 and 61%, and decreased epididymal fat pad weights (9 and 16%), whereas c9,t11 CLA had no significant effects. All CLA preparations increased liver weight, but not liver lipids. However, the increase in liver weight was much less in the c9,t11 CLA group (8%) than in the other two groups (25%) and might have been caused by the small amount of t10,c12 CLA present in the c9,t11 CLA preparation. Liver histology revealed that increased weight was due to hypertrophy. Markers of peroxisome proliferation, such as cyanide-insensitive palmitoyl CoA oxidase (EC 1.3.3.6) and carnitine acetyl transferase (EC 2.3.1.7) activities, were not increased by CLA. Both c9,t11 CLA and t10,c12 CLA were incorporated into phospholipids and triacylglycerols, but t10,c12 CLA only about half as much as c9,t11 CLA. In addition, linoleic acid and linolenic acid concentrations were lower in lipids of the t10,c12 CLA group compared with the c9,t11 CLA group. These data suggest that t10,c12 CLA stimulated the oxidation of all C18 polyunsaturated fatty acids. The results indicate that the t10,c12 CLA isomer, and not the so-called natural CLA isomer (c9,t11), is the active isomer affecting lipid levels in hamsters.


Assuntos
Ácido Linoleico/administração & dosagem , Lipídeos/sangue , Fígado/metabolismo , Peroxissomos , Tecido Adiposo/metabolismo , Animais , HDL-Colesterol/metabolismo , LDL-Colesterol/metabolismo , VLDL-Colesterol/metabolismo , Cricetinae , Epididimo , Ácido Linoleico/metabolismo , Masculino , Peroxissomos/efeitos dos fármacos , Isoformas de Proteínas/administração & dosagem , Isoformas de Proteínas/metabolismo , Distribuição Aleatória , Triglicerídeos/metabolismo , Ácido alfa-Linolênico/metabolismo
7.
Am J Clin Nutr ; 67(2): 322-31, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9459382

RESUMO

To investigate whether resistant starch (RS) affects putative risk factors for colon cancer, 24 healthy men consumed a daily RS supplement for 4 wk in addition to their habitual diet in a single-blind, randomized, balanced multiple crossover trial. During the first week, all subjects consumed the control supplement containing glucose. Subsequently, each subject consumed, in random order, a supplement with RS2 (uncooked high-amylose cornstarch), RS3 (extruded and retrograded high-amylose cornstarch), and glucose, each for 1 wk. The RS2 and RS3 supplements provided 32 g RS/d. Lithium was added to the supplements to measure compliance. Feces, 24-h urine, and breath samples, as well as a 24-h food-consumption recall were obtained weekly from each subject. Compliance as measured by urinary lithium recovery was satisfactory. The mean composition of the background diet did not differ between the various supplementation periods. Breath-hydrogen excretion, stool weight, and fecal starch excretion were significantly higher during RS than during glucose supplementation, but did not differ during RS2 and RS3 supplementation. There were no significant differences in fecal dry weight, pH, or short-chain fatty acid concentrations, nor in the pH, bile acid concentrations, cytotoxicity, or osmolality of fecal water. It is concluded that in healthy men, supplementing the habitual diet for 1 wk with 32 g RS2 or RS3/d compared with glucose had no effect on putative risk factors for colon cancer, except for increasing stool weight and colonic fermentative activity. There were no significant differences between the effects of RS2 and RS3 on the indexes studied.


Assuntos
Neoplasias do Colo/prevenção & controle , Dieta , Amido/administração & dosagem , Adulto , Ácidos e Sais Biliares/metabolismo , Testes Respiratórios , Culinária , Fezes/química , Glucose/metabolismo , Humanos , Hidrogênio/análise , Masculino , Fatores de Risco , Método Simples-Cego , Amido/análise , Amido/metabolismo
8.
Br J Nutr ; 78(2): 215-22, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9301412

RESUMO

The effect of a daily intake of 14 g inulin added to a low-fat spread on fasting blood lipids and gastrointestinal symptoms was investigated in sixty-four young healthy women in a randomized double-blind crossover study involving two periods of 4 weeks. The test spread with and without inulin replaced habitual spread during the test periods. No significant differences between the test periods in plasma total cholesterol, HDL-cholesterol, LDL-cholesterol and triacylglycerol concentrations were observed. Gastrointestinal symptoms assessed with questionnaires showed that in the inulin period there was a significantly (P < 0.05) higher degree of discomfort from flatulence and other gastrointestinal symptoms than in the control period. In general, there was no indication of intestinal adaptation to this level of intake of inulin.


Assuntos
Sistema Digestório/efeitos dos fármacos , Flatulência/etiologia , Alimentos Fortificados , Inulina/administração & dosagem , Lipídeos/sangue , Adulto , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Inulina/efeitos adversos , Triglicerídeos/sangue
10.
Am J Clin Nutr ; 64(3): 312-8, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8780339

RESUMO

The question addressed was whether dietary resistant starch would lower serum cholesterol and triacylglycerol concentrations in healthy normolipidemic subjects. In a randomized single-blind 3 x 3 Latin-square study with corrections for any carryover effects, 27 males and 30 females consumed supplements containing glucose or resistant starch (RS) from raw high-amylose cornstarch (RS2) or from retrograded high-amylose cornstarch (RS3). The RS2 and RS3 supplements provided 30 g RS/d. Each type of supplement was consumed in addition to the habitual diet for 3 wk. At the end of each 3-wk period, fasting blood samples and a 24-h food-consumption recall were obtained from each subject. The subjects collected 24-h urine samples for lithium determination, which was added to the supplements to check compliance. Mean lithium recovery was 97% and did not differ between supplements. The mean composition of the background diet was similar when the three supplements were taken. Body weight remained constant throughout the study. There were no significant differences in the fasting concentrations of serum total, high-density-lipoprotein (HDL), and low-density-lipoprotein (LDL) cholesterol; triacylglycerols, or 3 alpha-hydroxy bile acids after consumption of glucose, RS2, or RS3. Evidence is presented that the lack of effect of RS2 and RS3 on serum lipid concentrations cannot be explained by insufficient statistical power, a low dose, or a short duration of treatment. The subjects reported softer stools and more gastrointestinal symptoms after supplementation with RS than after glucose. Neither the RS2 nor the RS3 supplements lowered serum lipid concentrations in healthy, normolipidemic men and women.


Assuntos
Colesterol/sangue , Jejum , Lipídeos/sangue , Amido/farmacologia , Adolescente , Adulto , Idoso , Ácidos e Sais Biliares/sangue , Defecação , Feminino , Gastroenteropatias/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Cooperação do Paciente , Valores de Referência , Método Simples-Cego , Amido/administração & dosagem , Amido/efeitos adversos
11.
Nutr Res Rev ; 9(1): 1-31, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19094263
12.
Br J Nutr ; 74(6): 807-20, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8562568

RESUMO

Diets enriched in retrograded amylose (RS3) have been shown to lower serum cholesterol concentrations in rats. The possibility was tested that this hypocholesterolaemic effect of RS3 is caused by an increase in excretion of neutral steroids and/or bile acids. Six groups of ten rats were fed on purified diets containing either 12 or 140 g RS3/kg solid ingredients with and without added cholesterol (5g/kg). Low-RS3 diets, with and without added cholesterol, to which the bile-acid-binding resin cholestyramine (20 g/kg) was added, were used as reference. The high-RS3 diets v. the low-RS3 diets tended to reduce the increase in the total serum cholesterol concentration during the course of the experiment (P = 0.067), decreased serum triacylglycerol concentrations, raised total neutral steroids and total bile acids in caecal contents and faecal excretion of total bile acids, but lowered faecal excretion of neutral steroids. In addition, the serum concentration of total 3 alpha-bile acids was markedly raised by the high-RS3 diets. The high-RS3 diets raised the faecal excretion of lithocholic and muricholic acids, but lowered that of hyodeoxycholic acid, and increased the caecal amounts of lithocholic, ursodeoxycholic, beta-muricholic and omega-muricholic acids. Apart from the stimulation of faecal bile acids excretion, the effects of cholestyramine on bile acid metabolism differed at various points from those of RS3. Cholesterol feeding had predictable effects on cholesterol metabolism and led to greater elevating effects of RS3 on the faecal and caecal amounts of muricholic acids. The results suggest that the serum-cholesterol-lowering effect of high-RS3 diets may be explained by an increased influx of neutral steroids and bile acids into the caecum, and increased faecal excretion of bile acids, and/or by an altered intestinal bile acid profile.


Assuntos
Amilose/administração & dosagem , Ácidos e Sais Biliares/metabolismo , Colesterol/sangue , Esteroides/metabolismo , Análise de Variância , Animais , Ácidos e Sais Biliares/análise , Ceco , Resina de Colestiramina/administração & dosagem , Fezes/química , Conteúdo Gastrointestinal/química , Masculino , Ratos , Ratos Wistar , Triglicerídeos/sangue
13.
Lab Anim Sci ; 45(5): 588-91, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8569163

RESUMO

A method was developed to surgically implant a silicone/stainless steel fistula-cannula in the cecum of freely moving rats. The specially designed fistula-cannula allows sampling of cecal contents at any time without disturbing the physiologic functions of the intestinal tract, as evaluated by observation of general well-being and postmortem macroscopic inspection. The fistula-cannula was implanted in 12 male rats under general anesthesia. The animals remained in good health during the postoperative period lasting up to 9 weeks. They gained weight normally compared with a control group (n = 8) that had not undergone surgery. Samples of 0.2 to 1.0 g of contents could be collected with a microspatula, without the need to anesthetize the animal. The model provides a useful system for sampling cecal contents without the need to sacrifice the animal. Because it allows cross-over studies to be carried out, this approach may result in significantly reducing the number of animals required for digestive studies.


Assuntos
Cecostomia/veterinária , Ceco/fisiologia , Ratos Wistar/cirurgia , Animais , Peso Corporal , Cecostomia/métodos , Ceco/cirurgia , Desenho de Equipamento , Fístula/veterinária , Masculino , Ratos
14.
Eur J Clin Nutr ; 49(6): 446-57, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7656888

RESUMO

OBJECTIVE: To study the effect of amylose content on postprandial glucose and insulin responses in healthy subjects by serving fixed amounts of simple starchy foods with a varying but strictly controlled water, fat and guar gum content. DESIGN: A blind, randomised, balanced cross-over study. SETTING: The kitchen of the Nutrition Research Unit in the Unilever Research Laboratorium. SUBJECTS: Apparently healthy employees of Unilever Research Laboratorium. INTERVENTIONS: Subjects consumed, after an overnight fast, either a drink (12 men), a pudding (6 men and 6 women), a roll without (5 men and 6 women) or a roll with guar gum (12 men) as breakfast and the same amount of the same food as mid-morning snack. Each subject consumed the experimental food prepared in four ways: either with high- or normal-amylose starch, and with or without added fat. At 30 and 90 min after consumption of the breakfast or the snack a blood sample was taken for determination of glucose and insulin. RESULTS: Raising the amount of amylose in starchy drinks and puddings, but not in rolls, lowered postprandial glucose and insulin responses. Fat addition to starchy drinks, puddings and rolls attenuated postprandial glucose responses, irrespective of the amount of amylose or guar gum present. Addition of guar gum to rolls reduced glucose and insulin responses. Glucose tolerance tended to be less after consumption of the experimental foods as mid-morning snack than after consumption as breakfast. CONCLUSION: The physico-chemical composition of foods does influence the effect of the amylose:amylopectin ratio in starchy foods on postprandial glucose and insulin responses.


Assuntos
Amilopectina/farmacologia , Amilose/farmacologia , Glicemia/efeitos dos fármacos , Dieta , Insulina/sangue , Amilopectina/química , Amilose/química , Glicemia/análise , Estudos Cross-Over , Feminino , Teste de Tolerância a Glucose , Humanos , Masculino , Valor Nutritivo , Método Simples-Cego , Fatores de Tempo
15.
Br J Nutr ; 73(3): 423-32, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7766565

RESUMO

The present study describes the effect of replacement of digestible starch by resistant starch (RS) on diet-induced thermogenesis (DIT), postprandial glucose and insulin responses, and colonic fermentation. Ten healthy males consumed three test meals, consisting of diluted, artificially-sweetened fruit syrup and either 50 g raw potato starch (550 g RS/kg), or 50 g pregelatinized potato starch (0 g RS/kg) or 30 g pregelatinized potato starch plus 20 g lactulose (670 g indigestible disaccharide/kg). The meals were served in the morning after an overnight fast. Each volunteer consumed each meal twice on six separate days in random order. Metabolic rate was measured by indirect calorimetry in the fasting state for 15 min and postprandially for 5 h. Shortly before and hourly up to 7 h after consumption of the test meal, end-expiratory breath samples were obtained for H2 and CH4 analysis. Shortly before the meal and 30, 60, 180, and 300 min postprandially, blood samples were taken for glucose and insulin analyses. Postprandial increases in glucose and insulin levels were proportional to the amount of digestible carbohydrate in the meal. Breath H2 and CH4 concentrations indicated that the pregelatinized starch was not fermented and that lactulose was fermented rapidly. Fermentation of the raw starch started only 6 to 7 h after consumption, resulting in a rise in breath H2 but not in CH4. The replacement of 27 g digestible starch by RS in a single meal lowered DIT by on average 90 kJ/5 h, as could also be calculated by assuming that RS does not contribute to DIT. The ingestion of lactulose resulted in a substantial rise in DIT which was most probably caused by its fermentation.


Assuntos
Regulação da Temperatura Corporal , Digestão/fisiologia , Amido/administração & dosagem , Adulto , Glicemia/metabolismo , Testes Respiratórios , Colo/metabolismo , Humanos , Insulina/sangue , Lactulose/administração & dosagem , Lactulose/metabolismo , Masculino , Fatores de Tempo
16.
Br J Nutr ; 73(2): 287-98, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7718547

RESUMO

Male Wistar rats were meal-fed on diets containing various amounts of resistant starch in the form of raw starch (either amylomaize starch, potato starch or modified high-amylose starch) or retrograded starch (prepared from each of the starches) for 6 weeks. Two diets containing normal maize starch were fed as diets poor in resistant starch. Energy absorption (energy consumption minus faecal energy loss), growth, weight of the epididymal fat pads, serum total cholesterol and triacylglycerol concentrations and a number of intestinal and faecal variables were determined. The resistant starches affected all the variables determined except the serum total cholesterol concentration. Relationships were found between energy absorption and both growth and the weight of the fat pads, and between the weight of the fat pads and both the serum triacylglycerol concentration and the serum total cholesterol concentration. No clear differences between the effects of the two types of resistant starch (raw starch v. retrograded starch) were found except that raw potato starch hardly stimulated H2 excretion and led to lower amounts of propionic and butyric acids in the caecal contents than the other starches. The results suggest that dietary resistant starch reduces energy absorption leading to less abdominal depot fat and lower serum triacylglycerol concentrations.


Assuntos
Tecido Adiposo/metabolismo , Amido/administração & dosagem , Triglicerídeos/sangue , Animais , Colesterol/sangue , Digestão , Metabolismo Energético , Masculino , Ratos , Ratos Wistar , Aumento de Peso
17.
Am J Clin Nutr ; 59(3): 626-30, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8116539

RESUMO

Colonic fermentation of dietary carbohydrates and fiber might produce a protective effect against the development of large bowel cancer. Resistant starch, ie, starch that escapes small bowel digestion, is a candidate fermentable substrate that has been hitherto little studied. We supplemented 19 healthy volunteers with 15 g native amylomaize (Hylon-VII) three times a day, containing 28 g type II resistant starch, or with dextrins as a placebo for 7 d in a crossover design. Pre-experimentally, 11 subjects regularly produced breath methane and 8 did not. Resistant starch increased 24-h integrated excretion of breath hydrogen. The mean rise relative to placebo was 35% (P = 0.03) for all subjects and 60% for eight subjects not producing methane (P = 0.02). The 11 methane producers showed a 93% increase in breath-methane excretion on resistant starch (P = 0.03). Continued consumption of 28 g type II resistant starch/d is well tolerated and increases colonic fermentation in healthy volunteers.


Assuntos
Carboidratos da Dieta , Hidrogênio/análise , Metano/análise , Polissacarídeos/farmacologia , Amido/farmacologia , Adulto , Idoso , Ingestão de Energia , Humanos , Masculino , Pessoa de Meia-Idade , Polissacarídeos/efeitos adversos , Polissacarídeos/metabolismo , Respiração , Amido/efeitos adversos , Amido/metabolismo
18.
J Nutr ; 123(12): 2142-51, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8263609

RESUMO

Rats were meal-fed semipurified diets containing a low (0.8 g/MJ) and a high (9.6 g/MJ) amount of resistant starch (RS) or various amounts of RS (0.8 to 9.6 g/MJ) and guar gum (0 to 8.8 g/MJ). In one experiment, rats were fed the low and high RS diets in three dietary regimens (ad libitum consuming, 12 h ad libitum/12 h food deprived, and meal fed). Effects of RS and guar gum on serum postprandial and postabsorptive concentrations of total cholesterol (TC) and triacylglycerol (TAG), growth, hydrogen excretion, tissue weights and contents of small intestine and cecum, and pH of cecal contents were investigated. In addition, effects of RS on food intake, de novo hepatic synthesis of fatty acids and neutral sterols, and on lipoprotein lipase activity and weight of epididymal fat pads were investigated. Compared with feeding the low RS diet, the high RS diet reduced the serum TC and TAG concentrations, with these effects observed after 1 and 2 wk of feeding, respectively. The dietary regimen did not influence the effect of RS on the serum TC and TAG concentrations, but it did affect the serum TAG concentration. Resistant starch had no effect on the hepatic synthesis of fatty acids and neutral sterols or on the lipoprotein lipase activity in epididymal fat pads. Guar gum also reduced the serum TC concentration, but it had no effect on serum TAG concentration. The tissue weights and contents of small intestine and cecum as well as hydrogen excretion increased with increasing amounts of dietary RS and guar gum, whereas the pH of cecal contents decreased. No effects of RS on food intake and total body weight gain were found, whereas guar gum decreased weight gain. Feeding the high RS diet also led to a lower weight of the epididymal fat pads. We conclude that dietary RS can reduce serum TC and TAG concentrations and fat accretion.


Assuntos
Colesterol/sangue , Carboidratos da Dieta/metabolismo , Amido/metabolismo , Triglicerídeos/sangue , Animais , Ceco/anatomia & histologia , Ceco/química , Colesterol/biossíntese , Carboidratos da Dieta/administração & dosagem , Fibras na Dieta , Digestão , Ingestão de Alimentos , Epididimo/enzimologia , Ácidos Graxos/biossíntese , Galactanos/administração & dosagem , Galactanos/metabolismo , Hidrogênio/urina , Concentração de Íons de Hidrogênio , Intestino Delgado/anatomia & histologia , Intestino Delgado/química , Lipase Lipoproteica/metabolismo , Fígado/metabolismo , Masculino , Mananas/administração & dosagem , Mananas/metabolismo , Tamanho do Órgão , Gomas Vegetais , Ratos , Ratos Wistar , Análise de Regressão , Amido/administração & dosagem , Esteróis/biossíntese , Aumento de Peso
19.
J Nutr ; 123(10): 1724-31, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8410364

RESUMO

The effects on calcium and magnesium absorption of dietary native and retrograded cornstarch were studied in rats. Uncooked high amylose starch granules (35% of total glucose equivalents as enzyme-resistant starch) and cooked and cooled (-20 degrees C) high amylose starch (24% of total glucose equivalents as retrograded resistant starch) were used as test starches, and cooked normal starch (3% of total glucose equivalents as resistant starch) was used as control starch. Native vs. control starch raised the amount of polymerized glucose in ileum, but not in feces. Retrograded starch produced more polymerized glucose than control starch in both ileum and feces. When compared with control starch, ileal pH was significantly lowered by native starch and tended to be raised by retrograded starch. Cecal pH was lowered by the two preparations rich in resistant starch. Apparent absorption of calcium and magnesium was raised by native starch but not by retrograded resistant starch. Calcium concentrations in the liquid phase of the ileum tended to be elevated by native starch but were significantly lowered by retrograded starch relative to control starch. Magnesium and calcium concentrations in liquid cecal contents tended to be raised with native starch; they were unchanged with retrograded starch. It is suggested that native resistant starch raised calcium and magnesium absorption because it tended to enhance the solubility of these minerals in ileal and cecal digesta.


Assuntos
Cálcio/metabolismo , Carboidratos da Dieta/farmacologia , Magnésio/metabolismo , Amido/farmacologia , Absorção , Amilose/farmacologia , Animais , Peso Corporal , Ceco/anatomia & histologia , Ceco/metabolismo , Digestão , Fezes , Feminino , Glucose/metabolismo , Temperatura Alta , Concentração de Íons de Hidrogênio , Íleo/metabolismo , Tamanho do Órgão , Polímeros , Ratos , Ratos Wistar , Baço/anatomia & histologia
20.
Am J Clin Nutr ; 58(2): 180-6, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8338045

RESUMO

The impact of the amylose content of breakfast and lunch on postprandial variables was investigated in 22 normal-weight healthy males. Areas under the curve for insulin but not glucose were significantly smaller after the high-amylose breakfasts. Areas under the curve for both glucose and insulin were significantly smaller after the high-amylose lunches. Breath-hydrogen excretion over 14 h after breakfast indicated good digestibility of both types of meals. No systematic effect of amylose content on appetite or fullness ratings was observed. The amylose content of meals affects postprandial responses, but the effects are small and depend on meal size or composition.


Assuntos
Amilose/metabolismo , Dieta , Adulto , Amilopectina/administração & dosagem , Amilopectina/metabolismo , Amilose/administração & dosagem , Análise de Variância , Apetite , Glicemia/análise , Ácidos Graxos não Esterificados/sangue , Glicerol/sangue , Humanos , Fome , Insulina/sangue , Masculino , Pessoa de Meia-Idade , Saciação , Fatores de Tempo , Zea mays
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