Dietary fermentation

Rijnen, M.M.J.A., M.W.A. Verstegen, M.J.W. Heetkamp, J. Haaksma and J.W. Schrama, 2003a. Effects of dietary fermentable carbohydrates on behavior and heat production in group-housed sows. J. Anim. Sci. 81, 182-190. 

Fiber components are the principal energy source for colonic bacteria with a further contribution from digestive tract mucosal polysaccharides. Rate of fermentation varies with the chemical nature of the fiber components. Short-chain fatty acids generated by bacterial action are partiaUy absorbed through the colon waU and provide a supplementary energy source to the host. Therefore, dietary fiber is partiaUy caloric. The short-chain fatty acids also promote reabsorption of sodium and water from the colon and stimulate colonic blood flow and pancreatic secretions. Butyrate has added health benefits. Butyric acid is the preferred energy source for the colonocytes and has been shown to promote normal colonic epitheUal ceU differentiation. Butyric acid may inhibit colonic polyps and tumors. The relationships of intestinal microflora to health and disease have been reviewed (10). 

Various mechanisms have been proposed to explain the hypocholesterolemic effect of GA (Annison et al., 1995 Tiss et al., 2001). Some studies have suggested that the viscosity of fermentable dietary fiber contributes substantially to the reduction of lipids in animals and humans (Gallaher et al., 1993 Moundras et al., 1994). However, other studies suggested that this property is not related to plasma lipids (Evans et al., 1992). The mechanism involved is clearly linked to increased bile acid excretion and fecal neutral sterol or a modification of digestion and absorption of lipids (Moundras et al., 1994). 

The nature of the diet sets the basic pattern of metabohsm. There is a need to process the products of digestion of dietary carbohydrate, lipid, and protein. These are mainly glucose, fatty acids and glycerol, and amino acids, respectively. In ruminants (and to a lesser extent in other herbivores), dietary cellulose is fermented by symbiotic microorganisms to short-chain fatty acids (acetic, propionic, butyric), and metabohsm in these animals is adapted to use these fatty acids as major substrates. All the products of digestion are metabohzed to a common product, acetyl-CoA, which is then oxidized by the citric acid cycle (Figure 15-1). 

The main problems with early, irreversible MAOIs were adverse interactions with other drugs (notably sympathomimetics, such as ephedrine, phenylpropanolamine and tricyclic antidepressants) and the infamous "cheese reaction". The cheese reaction is a consequence of accumulation of the dietary and trace amine, tyramine, in noradrenergic neurons when MAO is inhibited. Tyramine, which is found in cheese and certain other foods (particularly fermented food products and dried meats), is normally metabolised by MAO in the gut wall and liver and so little ever reaches the systemic circulation. MAOIs, by inactivating this enzymic shield, enable tyramine to reach the bloodstream and eventually to be taken up by the monoamine transporters on serotonergic and noradrenergic neurons. Fike amphetamine, tyramine reduces the pH gradient across the vesicle membrane which, in turn, causes the vesicular transporter to fail. Transmitter that leaks out of the vesicles into the neuronal cytosol cannot be metabolised because... 

Processed mushy and canned garden peas (20 mg/kg) and all foodstuffs and amounts mentioned for Allura Red general use FDA can be safely used generally for coloring foods (including dietary supplements) in amounts consistent with GMP JECFA amount limited to 150 mg/kg in fermented milk and 100 mg/kg in baked goods ... 

The same methods (chemicals, enzymes, physical treatments) can be also applied on the cell wall materials not with the aim of extracting polysaccharides but with the aim of obtaining modified fibres. New properties concerning for exemple fermentability, ratio soluble/insoluble dietary fibre, hydration., can be obtained (1). 

During the in vitro fermention the amount of macromolecular pectin was diminished continuously. On the other hand the fraction of OligoGalA was increased at first and diminished later. The content of short chain fatty acids, which are typical end products of fermentation of dietary fibers rised permanently (Figure 5). Low-esterified pectins were fermented in vitro faster by human faecal flora than the high-esterified pectins. 

To ensure the safety of food products, representative samples must be inspected so that foodborne bacteria can be identified.15,18,19 Bacteria producing heat-stable enterotoxins, such as Staphylococcus aureus, may be identified by biochemical and serological techniques.20,21 Molecular methods are now widely used for the identification of many pathogenic foodborne bacteria,15,22,23 In addition bacteria used as starter cultures for cheese, yogurt, other fermented foods and beverages, and probiotic dietary supplements may be identified for quality assurance.22,24,25... 

Children from anthroposophic schools (Steiner schools), children from neighbouring schools Dietary detail not reported, but consumption of fermented vegetables and organic food assessed Significant reduction in atopic disease in anthroposophic children (Aim et al., 1999)... 

C. difficile overgrowth is present in only 15-25% of cases of AAD thus, other explanations are needed to understand the pathophysiology of diarrhea. There are multiple mechanisms which can account for the diarrhea associated with antibiotics. These include altered fermentation of the flora, changes in dietary fiber and overgrowth of other potential pathogens. 

Both dietary and endogenous ammoniagenic substrates are removed from the intestinal lumen by the osmotic cathartic action of nonabsorbable disaccharides such as lactulose and lactitol. These compounds are currently the main therapeutic agents for chronic HE. The efficacy of oral lactulose for the treatment of HE has been established in controlled trials [41-43]. Besides having a cathartic effect, lactulose lowers the colonic pH as a result of the production of organic acids by bacterial fermentation. The decrease in pH creates an environment that is hostile to the survival of urease-producing intestinal bac-... 

Goni I, Martin-Carron N. In vitro fermentation and hydration properties of commercial dietary fiber-rich supplements. Nutr Res 1998 18 1077-1089. 

Oufir LE, Barry JL, Flourie B, Cherbut C, Cloarec D, Bornet F, Galmiche JP. Relationships between transit time in man and in vitro fermentation of dietary fiber by fecal bacteria. Eur J Clin Nutr 2000 54 603-609. 

Hara, H., Suzuki, K., Kobayashi, S., and Kasai, T. (1996). Fermentable property of dietary fiber may not determine cecal and colonic mucosal growth in fiber-fed rats. /. Nutr. Biochem. 7, 549-554. 

In humans, dietary components not absorbed in the upper digestive tract reach the colon where they are fermented to acetate, propionate, butyrate. 

Pathology. Tooth plaque produces acids during the fermentation of dietary carbohydrates, causing the underlying tooth mineral to solubilize (demineralization). Upon restoration of a neutral plaque pH, mineral can reprecipitate (remineralization). When this equilibrium is lost, net demineralization occurs, causing dental caries. 

The main limitation to the clinical use of the MAOIs is due to their interaction with amine-containing foods such as cheeses, red wine, beers (including non-alcoholic beers), fermented and processed meat products, yeast products, soya and some vegetables. Some proprietary medicines such as cold cures contain phenylpropanolamine, ephedrine, etc. and will also interact with MAOIs. Such an interaction (termed the "cheese effect"), is attributed to the dramatic rise in blood pressure due to the sudden release of noradrenaline from peripheral sympathetic terminals, an event due to the displacement of noradrenaline from its mtraneuronal vesicles by the primary amine (usually tyramine). Under normal circumstances, any dietary amines would be metabolized by MAO in the wall of the gastrointestinal tract, in the liver, platelets, etc. The occurrence of hypertensive crises, and occasionally strokes, therefore limited the use of the MAOIs, despite their proven clinical efficacy, to the treatment of atypical depression and occasionally panic disorder. 

Later it was observed that butyric acid is a naturally occurring dietary HD AC inhibitor. It is formed upon dietary fiber fermentation within our digestive system. Although butyrate does not normally reach high enough levels for cancer treatment, it has been proposed that daily consumption over an individual s lifetime may provide chemoprevenfive effects. ... 

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