Use Of Dietary Fiber Research Articles

Funktionelle Darmerkrankungen

Functional gastrointestinal disorders particularly dyspepsia an irritable bowel syndrome are frequent problems for the general practitioner and also for the specialist. Both are diseases and not only a kind of discomfort. The high frequency of dispepsia and irritable bowel syndrome induces very high direct and indirect charges. Both diseases depend on a number of factors or causes, for whom the evidence is not good. But there are good experimental data for the visceral hypersensitivity as one of the main factors. Gastroscopy is the most important examination in the diagnosis of dyspepsia. Endoscopy has to be done in all patients with alarm symptoms an in all patients older than 45 years. The therapy of dyspepsia is an empirical one. The eradication of Helicobacter pylori is a therapeutical option, but only 8% of the patients will have benefit for a long time. Other therapeutical options are the use of proton-pump inhibitors, prokinetics or phytotherapeutics. The therapy of the irritable bowel syndrome depends on the subtype of the disease (diarrhea, constipation, abdominal pain, bloating). First of all a good doctor-patient relationship is mandatory. Furthermore the use of dietary fibre, antidiarrhoeics, laxatives and muscle relaxants may be beneficial. And phytotherapeutics can be an additional therapeutic approach.

Nutriceuticals in Cardiovascular Disease

In recent years, there has been a growing interest in the use of dietary fiber in health maintenance and disease prevention. A deficiency of fiber in the Western diet may be contributing to the current epidemics of diabetes mellitus, coronary artery disease (CAD), and colonic cancer. The awareness of fiber as a dietary supplement may have contributed to the reported 30% decline in death rate from CAD observed over the past 15 years. Psyllium is a soluble gel-forming fiber that has been shown to bind to the bile acids in the gut and prevent their normal reabsorption, similar to the bile acid sequestrant drugs. Psyllium is useful as an adjunct to dietary therapy (step 1 or step 2 American Heart Association [AHA] diet) in the treatment of patients with mild-to-moderate hypercholesterolemia. In combination with other cholesterol-lowering drugs, such as statins, psyllium provides an added benefit on cholesterol lowering, and is well tolerated and cost-effective.

Chronic diarrhea

Chronic diarrhea can be due to any of several hundred conditions. When investigation fails to uncover a specific cause that can be treated successfully, nonspecific therapy is implemented. This includes dietary alterations if specific aggravating foods can be identified, enteral or parenteral nutrition if nutritional status is compromised, and use of oral rehydration solutions if diarrhea produces volume depletion. Strategic use of dietary fiber can improve stool consistency and can be of special value when fecal incontinence is present concurrently. Medications of value include opiate antidiarrheal drugs, clonidine, octreotide, and bile acid-binding agents. Less potent opiates such as loperamide and diphenoxylate should be tried first, with more potent agents such as codeine, opium, and morphine used in refractory cases. Clonidine has both proabsorptive and motility effects that facilitate its antidiarrheal effect, but its antihypertensive action limits its utility. Octreotide is of great value in treating diarrhea due to endocrine tumors and dumping syndrome; its efficacy in other conditions or in nonspecific diarrhea is less well established. Bile acid binders such as cholestyramine or colestipol have several specific uses but have limited utility in nonspecific chronic diarrhea.

Dietary fibre, glycaemic response, and diabetes

The much publicised global trend in rising levels of obesity and diabetes has refuelled interest in the dietary intake of the macronutrients (fat, protein, and carbohydrates) necessary to maintain the state of normalcy (good health) of an individual. Both scientific and public attention have focused on the dietary mediation of chronic health syndromes, either through use of dietary supplements, or a review of the whole diet situation. Dietary supplements have been used extensively both as pharmacological supplements, food ingredients, in processed foods to aid weight control, and the regulation of glucose control for diabetic patients. Particular interest has focused on the use of dietary fibres, especially soluble dietary fibres (such as guar gum, locust bean gum, and psyllium fibres), resistant starch, and slowly digestible carbohydrates. These have been shown to alter food structure, texture, and viscosity, and hence the rate of starch degradation during digestion. Research has also illustrated an association between the rate of carbohydrate degradation during digestion, and the regulation of postprandial blood sugar and insulin levels. The current paper explores the potential use of dietary fibres in the treatment of obesity and diabetes.

Dietary fibres as “prebiotics”: Implications for colorectal cancer

A "prebiotic" is a nondigestible food ingredient whose beneficial effects on the host result from the selective stimulation of growth and/or activity of members of the bacterial community that inhabits the human bowel (the gut microbiota). Although much of the prebiotic literature focuses on nondigestible oligosaccharides, such as oligofructose, most dietary fibres that are fermentable carbohydrates could be considered as prebiotics. Early studies suggested that colonic bacteria were risk factors for colon cancer. However, altering the composition or metabolic activity of the bowel microbiota through the use of dietary fibre might be important in reducing the prevalence of colorectal cancer. Mechanisms for beneficial effects of prebiotics might include changing the activity of exogenous carcinogens through modulating metabolic activation and/or detoxification, or stimulating the production of the short-chain fatty acid, butyrate. However, modern analytical techniques suggest that an important consequence of a modified bacterial community could be a change in the expression not only of a range of different bacterial genes in bowel contents, but also in the bowel mucosa of the host. Analogous with observations with probiotics, the stimulation of cytokines and modification of immune responses could be important in producing beneficial effects. Compared with transitory effects of probiotics, the prebiotic action of fermentable carbohydrates potentially provide the opportunity for sustainable modulation of activity of the gut microbiota. However, their mechanisms of action in humans are speculative, and research aimed at providing an integrated view of the gut microbiota and dietary fibre nutrition of humans needs to be developed.

Effects of dietary fiber on inflammatory bowel disease

The chronic idiopathic inflammatory bowel diseases (IBDs), namely Crohn's disease and ulcerative colitis, appear to be derived from an inappropriate reaction towards a luminal agent, most probably driven by the intestinal microflora, which upregulates the synthesis and release of different pro-inflammatory mediators, thus contributing to tissue damage that characterizes these intestinal conditions. Several studies have reported that IBD is associated with impairment in short-chain fatty acid (SCFA) production, mainly acetate, propionate, and butyrate. They are produced in the large bowel by anaerobic bacterial fermentation of undigested dietary carbohydrates and fiber polysaccharides, with butyrate being considered as the major fuel source for colonocytes. These SCFAs have been proposed to play a key role in the maintenance of colonic homeostasis. Therefore, it is reasonable to consider therapeutic approaches that increase colonic SCFA production, as it can be achieved by administration of dietary fiber to IBD patients. Unfortunately, there is quite limited documentation of efficacy of dietary fiber in properly designed trials. This review discusses the rationale, available evidence for the use of dietary fiber and its mechanisms of action in the treatment and prevention of IBDs.

Effect of dietary fibre on the behaviour and health of the restricted fed sow

The usual restricted feeding level during gestation, whilst adequate to maximise economic performance, might not fulfil behavioural needs of the sow. Hunger and frustration of feeding motivation have been linked to the occurrence of stereotypic activity, and accentuate aggression and feeding competition in group-housing systems. Incorporation of fibre in diets to increase bulk, without changing the daily dietary energy supply, has been shown to result in at least a doubling of eating time, a 20% reduction in feeding rate, a 30% reduction in operant response in feed motivation tests, a reduction of 7–50% in stereotypic behaviour, and a decrease in general restlessness and aggression. Results suggest a reduced feeding motivation, but only if nutrient intake with fibrous diets meets the nutrient requirements of the animals. Investigations of circulating glucose, insulin and volatile fatty acid levels in sows fed fibrous diets indicate a more constant nutrient absorption and greater microbial fermentation in the gut, which should increase satiety. There is inadequate information on effects of dietary fibre on physiological stress and health. In addition to welfare considerations, a range of technical requirements and economic factors must be considered when making decisions on the use of dietary fibre during gestation.

Supplementation with gum arabic fiber increases fecal nitrogen excretion and lowers serum urea nitrogen concentration in chronic renal failure patients consuming a low-protein diet

In chronic renal failure (CRF), plasma concentrations of the products of protein metabolism are increased. Current dietary management is to prescribe a decrease in protein intake. The use of dietary fiber to increase fecal excretion of retained metabolites in CRF may be a beneficial adjunct to a low-protein diet (LPD). Colonic bacteria ferment dietary fiber, providing them with energy for growth and nitrogen incorporation, in turn, increasing nitrogen excretion in feces. Sixteen CRF patients consuming an LPD were randomly assigned to receive a supplement of a highly fermentable fiber, gum arabic (50 g/d), or a placebo (1 g pectin/d) in a prospective, single-blind, crossover design. Fecal bacterial mass and fecal nitrogen content were significantly increased during supplementation with gum arabic compared with the baseline LPD or supplementation with pectin. Serum urea nitrogen was significantly decreased during supplementation with gum arabic compared with the baseline LPD or supplementation with pectin. Nitrogen balance did not change significantly.

Toxicological evaluation of dietary fibre

Dietary fibre is classically described as plant material that resists digestion by human digestive enzymes. It is a generic term that includes a number of substances of unique chemical structure, characteristic physical properties, and individual physiological effects. With the exception of lignin, all of the materials that are classified as dietary fibre are fermented to some extent by the colonic bacteria. The products of this fermentation are hydrogen, methane, carbon dioxide and short-chain volatile fatty acids such as acetic, propionic, butyric and valeric. The major constituents of dietary fibre are the principal components of the plant cell wall: cellulose, hemicellulose, pectic substances and lignins. However, the term dietary fibre has been expanded to include natural or semi-synthetic polysaccharides such as gums, mucillages, algal polysaccharides, chemically modified cellulose and resistant starches. The major carbohydrates of saccharidic fibres are glucose, mannose, galactose, xylose, arabinose, rhamnose, fucose, galacturonic and glucuronic acid and in some cases (i.e. carrageenans) osidic sulphate esters. Lignins are complex, cross-linked phenylpropane polymers containing sinapyl, coniferyl and coumaryl alcohols. The major reasons for having fibre (in the broad sense of the word) in food are either nutritional (low calorie bulking agent--health promoting effect), technological or both. Its concentration in food may vary from a fraction (gums, mucillages, algal polysaccharides) to a few percent, with a maximum near 10% (plant polysaccharides). Until recently most dietary fibres were consumed as a result of their natural occurrence in fruits, cereals or vegetables and only a few of them were added to food, mainly for technological reasons (for example gums or algal polysaccharides like carrageenans or pectins). More recently, because of the development of food industry, and because of their recognized role in human health and preventive medicine, a great variety of dietary fibres has been developed to be added to marketed food products (presently some 80 different products are used in US food products). For the same reasons, commercial use of dietary fibre is likely to increase in the near future, together with research for new and well characterized products with specific physiological or technological properties. Moreover, very soon biotechnologically synthesized and/or processed dietary polysaccharides with fibrelike activities will become available.

Food fiber choices for diabetic diets

The use of dietary fiber (DF) in the diet of diabetics, although recommended, is often prevented by a limited tolerance and/or by the high cost and unpalatability of fiber supplements. Knowing that only or mainly the water soluble fraction of DF is effective in modulating postprandial hyperglycemia, the DF content (soluble, insoluble, and total) of a variety of common foodstuffs was determined. Such data were then utilized in the formulation of two complete meals, isocaloric and isoglucidic, characterized by a high-soluble, low-soluble, and total fiber content. The meals were administered to 13 NIDDM patients in good metabolic control. The data confirmed a significant reduction (p less than 0.001) of postprandial hyperglycemia and a moderate less significant reduction of insulinemia after the high fiber meal.

Use of dietary fiber and stimulus control to treat retentive encopresis: a multiple baseline investigation.

Diet modification and stimulus control training for retentive encopresis was evaluated in a multiple baseline across subjects design. Three encopretic boys were assessed for 6, 10, and 14 weeks of baseline. Diet modification comprised increasing dietary fiber and water intake through a point contingency, and stimulus control comprised scheduled toileting with limited, contingent use of suppositories. Diet changes were associated with increases in appropriate toileting and decreases in accidents. All subjects attained four consecutive accident-free weeks, and gains were maintained for 1 year. Only one subject required limited use of suppositories. Results suggest diet change is one alternative to purgatives in treatment for retentive encopretics. Qualifications of the approach are noted, and recommendations are made for future research.

Dietary fibre and fluid in the control of constipation in a nursing home population.

A 12-month study showed that constipation in institutionalized elderly patients can be eliminated effectively and safely by the planned use of dietary fibre and a controlled fluid intake. The diet of a group of volunteer nursing home patients (average age, 83.5 years) was supplemented to provide a daily dietary fibre intake of 25 g per person. Aperient use was almost eliminated, bowel function improved, and there appeared to be no adverse effects on body weight, or on nutritional or mineral status.

Effect of dietary fiber on bioavailability of zinc and copper and histology in rats

Effects of prolonged use of dietary fiber on the absorption of zinc and copper were determined. In addition, differences in histopathology of small intestine, liver and kidney were evaluated. Four groups of rats were fed semipurified diets containing no fiber (C) 7.5% of either pectin (P,) guar meal (G.) or carrot (Ca). Radioisotopes with short half lives ( 69mZn and 64Cu) were used to measure absorption and endogenous losses of zinc and copper. Fiber did not adversely affect (P<.05) the absorption or endogenous excretion of either isotopes. At the end of the experimental period distribution of the absorbed zinc in gastrointestinal tract, liver and kidney was measured using 65Zn as a tracer. The 65Zn content of the intestinal tissues and liver was higher (P<.05) in the pectin group which also showed maximum incidence of blunting and fusion of the villi of distal ileum. The growth rate and weight of the rats on the pectin diet were significantly lower (P<.05) than on the control diet.

Diagnosis and Management of Diabetes Mellitus: A Clinical Manual for Medical Students, Residents, and Primary Care Physicians

Dr O. Charles Olson has written a clear and concise manual on the care of the diabetic patient. Based on more than 30 years of clinical experience, he has compiled a soft-cover book of 35 chapters totaling 275 pages. It is written for medical students, house officers, primary care physicians, and, I would add, could be very useful to interested nurses, allied health professionals, and well-informed patients. The initial section clearly reviews the newer classification of diabetes. This is followed by an exceptionally helpful chapter on diagnosis, including criteria for diagnosis, preparation and timing of an oral glucose tolerance test (OGTT), when not to do an OGTT, and nondiabetic causes of abnormal OGTT results. Chapters 3 through 9 deal with the day-to-day management of the type I and II diabetic. Dietary management is covered in a cookbook fashion, and an interesting page on the use of dietary fiber is presented.

EFFECTS OF DIETARY FIBER ON GROWTH, ASSIMILATION AND CELLULASE ACTIVITY OF THE PRAWN (Macrobrachium rosenbergii)1

ABSTRACTCellulose fiber comprising up to 30% of an isonitrogenous series of diets (0, 5, 15 and 30% fiber concentration) did not suppress growth of prawn having average initial weights of 0.08 ± 0.002 g over a 12‐week period. In addition, dietary fiber concentrations of 5 and 20% were found to stimulate growth over an 8‐week period among prawn having initial average weights of 1.48 ± 0.054 g, as opposed to 0% fiber concentration, which had no significant effect on growth.Cellulase activity measured in hepatopancreas tissues by viscometric techniques was shown to be positive with a six‐fold increase in activity occurring in adult prawn (11 ± 1.16 g) when compared to smaller prawn (1 ± 0.06 g). However, activity in both sizes of prawn was not found to be proportional to increases in dietary fiber concentrations. Total organic carbon assimilation decreased while nitrogen assimilation efficiency increased in response to increasing dietary fiber concentration. Results from the present study indicated that use of dietary fiber may make a significant contribution to commercial formulations of cost‐effective crustacean diets.

Fiber, intestinal sterols, and colon cancer

It has been postulated that dietary fiber's protective effect against the development of colon cancer, diverticular disease, and atherosclerosis may be due to the adsorption and/or dilution of intestinal sterols such as bile acids and neutral sterols and their bacterial metabolites by component(s) of fiber. Dietary fiber is made up of four major components—cellulose, hemicellulose, lignin, and pectin. There is evidence that hemicellulose and pectin may induce an increase in fecal bile acid excretion in man which may be accompanied by a decrease in serum cholesterol. Natural fibers, such as rolled oats, alfalfa, guar gum, and Bengal gram have been shown to have hypocholesterolemic properties and alfalfa, wheat straw, and some other fibers bound considerable amounts of bile acids in vitro. On the other hand, wheat bran, oat hulls, and all the synthetic fibers tested bound only negligible amounts of bile acids under the same conditions. Vegetarians in the United States have lower plasma lipids and different plasma lipoprotein patterns than those of comparable control populations on regular mixed diet. They also have smaller daily fractional turnover rates of cholic acid and deoxycholic acid pool size. In addition, populations on a mixed Western diet, where the rate of large bowel cancer is high (North American, English, Scottish, etc.) degraded and excreted cholesterol and bile acid metabolites to a greater degree than populations where the rate of colon cancer is comparatively low (Ugandan, Japanese, etc.). It cannot be denied that the fiber theory linking fiber deficiency with the development of colon cancer and other diseases, is simple, attractive, and appears to be firmly based in common sense. When subjected to research studies, however, the situation appears much more complex than expected. Although some progress is being made, the data are often contradictory and confusing, probably due to lack of adequate documentation of fiber intake (e.g., use of dietary fiber instead of crude fiber) and/or the absence of detailed information on the chemistry of the fiber itself.