Scientist - News - 19-03-2009:
«BackPrebiotics: the next trend in nutrition? Beintema, Nienke An Italian study recently showed that prebiotics reduce infections in infants. Is this study really revolutionary? Two experts provide some insights into the potential of prebiotics. The February issue of the journal Clinical Nutrition featured an Italian study on prebiotics in infant formula. The researchers from the University of Naples, Italy, studied 342 healthy, bottle-fed infants. Half of them received formula supplemented with a mixture of galacto- and fructo-oligosaccharides (GOS and FOS), and the other half received formula without these prebiotics. After twelve months, the researchers concluded that the incidence of gasteroenteritis was significantly lower in the prebiotics group, and that this group received fewer antibiotics. Direct evidence News sources on the Internet were quick to pick up the story: prebiotics were to be the next trend in nutrition. This study, however, is not the first to show a beneficial effect of prebiotics. So why the hype? "What is really new about this study is that it shows a direct causal relationship between prebiotics and health parameters," says researcher Koen Venema from TNO in Zeist. "Earlier studies focused on the effect of prebiotics on the composition of the intestinal microbiota. Prebiotics seem to increase the number of beneficial bacteria, notably bifidobacteria. This has always been interpreted as an indirect indication that prebiotics are conducive to our health, but direct evidence has been scarce." Danone Research in Wageningen is also positive about the Italian study. "New about this study is that it is performed in a large cohort of otherwise healthy infants, using a standard formula with a moderate dose of prebiotics," says Mirjam Govers, director of research communications at Danone Research. "The results are important because they confirm and extend previous studies in this paediatric domain. These showed that specific prebiotics in infant formulas reduced the incidence of infections and allergic symptoms in children at risk of allergy, both at 6 months and at 2 years. Building this ‘pyramid of evidence’ is of key importance to convince opinion leaders in this field about the clinical health benefits of prebiotics in infant formula." Communicating the concept Venema and his colleagues at TNO are screening a wide range of potential prebiotics for industrial clients. "An ingredient may only be called a prebiotic if it is beneficial to our gastrointestinal flora," he explains, "but this definition is still debated. Is it enough if only the bifidobacteria increase in number, for instance? And what is the clinical meaning of that? In any case, sufficient knowledge is lacking on other potential effects of prebiotics." The best-known prebiotics, as Venema points out, are GOS, FOS and inulin, all of which are carbohydrates. Not all carbohydrates, though, are potential prebiotics. "In the case of regular whole-wheat bread, for instance," he explains, "most of the starch is broken down by enzymes in the small intestine. Hardly any of the carbohydrates reach the large intestine, where most bacteria are active." A newly developed bread, available as ‘Vitaal Flora’ in The Netherlands, contains inulin, but it is marketed as containing dietary fibre. Venema: "The concept of prebiotics clearly hasn’t taken off the way probiotics have. There is a lot of work to be done to communicate the added value of prebiotics." Clinical evidence Danone Research focuses its work on prebiotics in infant formulas. "The strategy of Danone is to use human breast milk as the ‘gold standard’ in developing infant formulas," says Govers. "We aim to unravel the complexity of human milk, which contains many immuno-modulating components. Human milk contains a significant amount of prebiotic oligosaccharides – even more than protein. We study the chemical composition and biological functionality of human milk ingredients, and we translate this knowledge into our infant milk formulas, to bring them closer and closer to the health benefits of human milk." Govers agrees with Venema that the benefits of prebiotics are still not widely recognised, and the potential could be better developed. "We think that prebiotics can play an important role in subjects in which the microbiota and/or immune system are either in development, or in imbalance for whatever reason," she states, "such as young babies, people with allergies or who use antibiotics, and immuno-compromised patients." Both researchers emphasize that the role of prebiotics in healthy individuals needs to be further explored. Govers: "In infant formula, the addition of prebiotics has been a trend since the year 2000. Evidence for the previously mentioned GOS/FOS mixture is strong, while many other prebiotic mixtures on the market are not supported by sound clinical evidence." More information:
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