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Finally, ingestion of yogurt has been shown to stimulate the production of cytokines by blood mononuclear cells. In addition, these or similar strains have been reported to decrease fecal and urinary mutagenicity in healthy volunteers consuming fried ground beef. The hypocholesterolemic effects of probiotics are the subject of controversy. As discussed recently by Jackson et al 13 , the major limitations of these earlier studies were as follows: Jackson et al 13 concluded that experimental evidence does not support a hypocholesterolemic effect for probiotics when consumed in easily achievable quantities.
Rotavirus-induced diarrhea and possibly colon cancer are the only disorders for which there is evidence of disease reduction from probiotic consumption. For rotavirus diarrhea, different groups of investigators working under a variety of conditions have consistently reported that humans consuming probiotic-fermented dairy products had a shortening of episodes or a reduction in risk of the disease 9. For colon cancer, the evidence comes exclusively from experimental animals, in which lactobacilli and bifidobacteria were shown to decrease the number of aberrant crypt foci, a marker for risk of cancer development after treatment with a chemical carcinogen The only prebiotics for which sufficient data have been generated to allow an evaluation of their possible classification as functional food ingredients are the inulin-type fructans, which include native inulin, enzymatically hydrolyzed inulin or oligofructose, and synthetic fructooligosaccharides 15 , Inulin-producing plant species are found in several monocotyledonous and dicotyledonous families, including Liliaceae, Amaryllidaceae, Gramineae, and Compositae.
However, only one inulin-containing plant species chicory, Cichorium intybus is used to produce inulin industrially. Native inulin is processed by the food industry to produce either short-chain fructans, specifically oligofructose degree of polymerization: An analytic method has been developed to quantify inulin and oligofructose in plants and food products. After a multicenter validation ring test, this method was adopted as Association of Official Analytical Chemists method Inulin and oligofructose are present in significant amounts in miscellaneous edible fruit and vegetables; average daily consumption has been estimated at 1—4 g in the United States and 3—11 g in Europe.
The most common sources are wheat, onion, banana, garlic, and leeks Chicory inulin and oligofructose are officially recognized as natural food ingredients in most European countries, and they have a self-affirmed generally recognized as safe status in the United States.
The synthetic inulin-type fructans are obtained by enzymatically catalyzed fructosyl transfer using fungal fructosyl transferase from and between sucrose molecules. In Europe, these are classified as novel foods. Inulin-type fructans are used as sugar substitutes, as fat replacers inulin only , and as a means of providing texture, stabilizing foam, or improving mouth feel in miscellaneous products such as fermented dairy products; desserts such as jellies and ice creams; bakery products such as cookies, breads, and pastries; spreads; and infant formulas.
In a recent consensus paper inulin-type fructans were classified as nondigestible oligosaccharides Moreover, there is evidence that they are not absorbed to any significant extent. Thus, it has been proposed that they be called a colonic food ie, a food entering the colon and serving as a substrate for the endogenous bacteria, thereby directly providing the host with energy and metabolic substrates. The idea that inulin-type fructans are fermented by bacteria colonizing the large bowel is supported by many in vitro both analytic and microbiological and in vivo studies, which, in addition, confirm the production of lactic and short-chain carboxylic acids as end products of the fermentation.
Furthermore, it was shown in human in vivo studies that this fermentation leads to the selective stimulation of growth of the bifidobacteria population, making inulin-type fructans the prototypes of prebiotics 2. The nondigestible carbohydrates dietary fiber have been reported to impair the small-intestinal absorption of minerals because of their binding or sequestering action.
However, the minerals that are bound or sequestered and, consequently, not absorbed in the small intestine, do reach the colon, where they may be released from the carbohydrate matrix and absorbed. In addition, independent of any binding or sequestering of minerals, some nondigestible carbohydrates eg, inulin-type fructans may improve mineral absorption and balance because of an osmotic effect that transfers water into the large bowel, thus increasing the volume of fluid in which these minerals can dissolve.
Finally, studies of ileostomy patients showed that inulin-type fructans do not impair mineral absorption in the small intestine Indeed, this study showed that the amount of calcium, magnesium, and iron ions recovered in the ileostomate over 3 d is not significantly modified after supplementing the diet with 17 g of these fructans daily.
More recently, in vivo human studies confirmed the positive effect of inulin and oligofructose on the absorption and balance of dietary calcium but not of iron, magnesium, or zinc. In the first published report, 9 men mean age: In the second study, the calcium balance of 12 males between the ages of 15 and 18 y who consumed The effects of inulin-type fructans on triglyceridemia have been studied in both animals and humans. In rats, a decrease in serum triglyceridemia in both the fed and the fasted state was consistently reported in several studies; in healthy humans, only fasting triacylglycerol was measured, and it was modified in only one study.
No data have been published for hypertriglyceridemic patients. Data concerning the effects of inulin-type fructans on cholesterolemia or lipoproteinemia are scarce The hypotriglyceridemia is due mostly to a decrease in the concentration of plasma VLDL. This effect likely results from a decrease in the hepatic synthesis of triacylglycerol rather than from a higher catabolism of triacylglycerol-rich lipoproteins. These data support the hypothesis that decreased de novo lipogenesis in the liver through a coordinate reduction of the activities of all lipogenic enzymes is a key event in reducing VLDL triacylglycerol secretion in fructan-fed rats.
That de novo lipogenesis is the basis for the hypotriglyceridemic effect of fructans in the rat liver might explain the lack of effect observed in healthy humans, who ordinarily eat much less carbohydrate than do rodents. Some experiments should be performed in either obese patients or insulin-resistant persons consuming high-carbohydrate, high-energy diets To explain a possible effect of inulin-type fructans on the modulation of triacylglycerol metabolism, 2 effects are hypothesized.
The first effect is the modification of glucose or insulin concentrations, because dietary modulation of lipogenesis is often linked to such physiologic changes. Indeed, the induction of lipogenic enzymes by glucose, occurring via an increased gene transcription, is potentiated by insulin. The second effect is the production in the large bowel of short-chain carboxylic acids, which results in a more than 2-fold increase in the portal concentration of both acetate and propionate in oligofructose-fed rats.
Endocrinol Nutr. Nov;63(9) doi: /www.farmersmarketmusic.com Epub Sep An update on probiotics, prebiotics and symbiotics in clinical . Accumulating research evidence suggests that probiotics and prebiotics, which both influence the endogenous flora, may have a role in human therapies.
Moreover, propionate was reported to inhibit fatty acid synthesis, whereas acetate is a lipogenic substrate. Long-term 16 wk administration of oligofructose also decreases total serum cholesterol concentrations in rats, but does not influence either the absorption of dietary cholesterol or the excretion of cholesterol or bile acids in ileostomy subjects.
For inulin-type fructans, claims that they reduce the risk of disease are only tentative and still need to be supported and validated by further research. These claims include the following: Constipation relief resulting from fecal bulking and possible effects on intestinal motility. Reduction of risk of osteoporosis if inulin-type fructans improve the bioavailability of calcium and if this functional effect is followed by a more physiologic change in peak bone density and mineral bone mass.
Reduction of the risk of atherosclerotic cardiovascular disease associated with dyslipidemia, especially hypertriglyceridemia, and insulin resistance, which in particular is known to be associated with hyperenergetic, high-carbohydrate feeding regimens. The reduction of risk via a hypocholesterolemic effect needs further investigation as does the proposal of a sound mechanistic hypothesis to be tested in humans. Reduction of the risk of obesity and possibly of type 2 diabetes, both of which are known to be associated with insulin resistance.
Cancer is a last area for further research on the ability of inulin and oligofructose to reduce risk of disease. In 2 studies, feeding rats with inulin significantly reduced the incidence of the so-called aberrant crypt foci induced by such colon carcinogens as azoxymethane and dimethylhydrazine 26 , In the strategy for functional food development 3 , finding cancer-inhibitory effects in experimental animals is the first step, ie, identifying effects that, because of their potential implications for human health, will require careful evaluation, including relevant human studies.
The strength of experimental evidence supporting claims of a functional effect from probiotics and prebiotics is summarized in Table 1 as strong, promising, or preliminary or as no effect or unknown. The classification of evidence is the result of the evaluation, by the author, of the scientific data reviewed in this article.
It also relies on previous evaluations of the properties of probiotics 28—30 and prebiotics 15, 31, Some probiotics are known to alleviate lactose intolerance. A systematic review and meta-analysis of the prebiotics and symbiotic effects on glycaemia, insulin concentrations and lipid parameters in adult patients with overweight or obesity.
Effect of Probiotics on Glycemic Control: Brian E Lacy , William D. Of microbes and men.
Patrick Brueggman named the new president and chief executive officer of the company. It also relies on previous evaluations of the properties of probiotics 28—30 and prebiotics 15, 31, Rotavirus-induced diarrhea and possibly colon cancer are the only disorders for which there is evidence of disease reduction from probiotic consumption. I am often asked by a customer, what is the difference between your product and others? With regard to a possible role for probiotics or prebiotics in reducing the risk of diseases, the evidence is much more limited; in most cases it is either preliminary or there is no evidence at all Table 2. But the claims may not be related to a disease. To get it you have to go to a doctor for example.
Ele Ferrannini Diabetes care A Systematic Review and Meta-Analysis. Carey , Won Kyoo Cho Clinical gastroenterology and hepatology: By clicking accept or continuing to use the site, you agree to the terms outlined in our Privacy Policy , Terms of Service , and Dataset License. I think that we are engaging in semantics here. I am really confused about the fact that disease-related advertising is prohibited, but health-related advertising is not.
The consumer is going to be very confused, because lack of health is disease. By now many groups in Europe are working on either treating or preventing specific diseases with probiotic [foods]. Should they be applying for approval as medicines, not as foods? What the consumer wants is something to prevent disease or treat disease. The consumer is obsessed with disease. A group of foods intended for the treatment of diseases has been already defined, the foods for special dietary uses.
There is no need to define another group. I think what everybody finds a little bit difficult is to accept food that is put on the market as conventional food, while at the same time a claim is made that it is suited for treatment. No legislative system can allow these 2 things to go together. I would argue that the specified foods are offered for deficiencies, for example a vitamin deficiency, but are not actually treating active disease conditions.
There is no food I know of that is certified as a food to treat a disease. Our law, for instance, considers a product that is primarily intended for treatment no longer a food. If the primary intention is not the treatment then you can market it as food. I agree with Dr Schroeter that one should clearly differentiate between the regulation for probiotics and for health claims in general, concerning all kinds of foods.
It seems to me that we should have different levels of scientifically validated claims and different food categories.
The general food for the population, a specifically claimed food for certain applications, and food that would be almost a medicine. Dr Huis in't Veld: I agree with Professor Mogensen that it is very important to have international guidelines for functional foods, to which pre- and probiotics also belong. In Japan and the United States, for example, this has already been accepted by legislation, but not in Europe at the moment. There are guidelines in Sweden.
Last month, guidelines for health claims were issued in the Netherlands and in the United Kingdom guidelines will very soon be available. In the Netherlands we are now able to go to an independent organization to deliver our scientific evidence for health effects. But the claims may not be related to a disease. All these guidelines agree that the industry is responsible for providing scientific information for the health effects to come to some health claims.
This information is to be given to the consumer. But medical claims on foods are not allowed in any of the EU [European Union] countries. So you can say something on the intestinal flora.
Then you have a probiotic drug, which you can't get in the supermarket. To get it you have to go to a doctor for example. There are approved claims and nonapproved claims. I hope that guidelines will become introduced for the whole of Europe and actually all over the world. There is consensus that there should be adequate consumer information. How to do that is another issue. However, there is one barrier in my view, which is Article 18 of the German national food law, prohibiting disease-related advertising.
That should not to be removed, but modified on sound scientific evidence. I think we have to broaden definitions and should get away from health food. Probiotics is much more than food. Probiotics is health maintenance and risk reduction. We have not talked about nasopharyngeal or skin probiotics. There was only one talk about urogenital infection, but there are many other forms of applications. In countries like Japan and the United States the distinctions between foods and pharmaceuticals are different from those in Europe. That is the point we have to discuss as well for international acceptance.