The growing body of science led co-chair of the conference, Professor Allan Walker from Harvard Medical School, to tell NutraIngredients.com: "Prebiotics potentially may be more relevant [for health] than probiotics."
Belgium's Orafti has been influential in building the science behind inulin and oligofructose, backing research into potential benefits for a variety of health conditions ranging from bones to colorectal cancer, from immunity to satiety and weight management.
"Science is the basis," said Orafti's Douwina Bosscher. "By thinking this way, we work with the best scientists to increase our knowledge to gather more data on our food ingredients. Our clients can then use our knowledge to better communicate with consumers."
Co-chair of the conference, Professor Glenn Gibson from the University of Reading who first coined the term 'prebiotic' with Marcel Roberfroid from the Catholic University of Louvain (J. Nutr. 1995, Vol. 125, pp. 1401-1412), confirmed that the most extensive research to date is with the inulin-type fructans, non-digestible carbohydrates that reach the colon intact and are hydrolysed by specific 'positive' members of the colon microflora.
One hundred and sixty participants from 25 countries heard the old and new data concerning bone health, a key area for the prebiotics, as well as colorectal cancer, a disease that accounts for nine per cent of new cancer cases every year worldwide.
Dr. Steven Abrams from Baylor College of Medicine in Texas presented results from a recent, and yet to published, long-term human intervention study of inulin and oligofructose (Synergy1) of pubertal adolescents, research described by Dr. Bosscher as "breakthrough data."
Dr. Abrams randomised 100 adolescents (50 girls, aged 9 to 12) to receive Synergy1 or a maltodextrin placebo for one year. The effects were determined by measuring bone mineral density and content (BMD and BMC), calcium absorption, and polymorphism in the Fok1 vitamin D receptor.
The Houston-based researcher reported that the net benefit of the inulin-oligofructose supplement was about 30 milligrams of additional calcium accretion into the skeleton every day, which would equate to an extra 11 grams of calcium every year.
An interaction of the vitamin D receptor was also reported, with certain groups less responsive to the positive effects of the prebiotic. This suggests an alternative 'active absorption' mechanism may also be occurring for calcium, possibly complementing the 'traditional mechanism' of passive absorption - selective fermentation pattern results in the production of short chain fatty acids, which decrease the pH within the colon, improving the solubility of the calcium present. The calcium is then better absorbed into the body.
But the implication that the calcium absorption may also be active "opens up whole new avenues of research," said Dr. Bosscher.
Dr. Véronique Coxam from France's INRA reviewed the research in early and late post-menopausal women's bone health, a demographic at a significantly high risk of osteoporosis. Although less studied that the adolescents, Dr. Coxam did report the potential synergy between inulin and oligofructose and soy isoflavones, compounds increasingly being taken by older women to reduce the symptoms of the menopause.
Results from a recent study to be published in the British Journal of Nutrition with 15 late post-menopausal women given a daily inulin, oligofructose supplement of 10 grams reported that calcium and magnesium absorption were significantly increased by 23 per cent.
"Given the promising results in the adolescents (in terms of bone mineral density), we need to fully investigate the long-term effect of such compounds in adults and elderly," said Dr. Coxam.
Colorectal cancer is also an area that has a growing but already significant number of studies linking prebiotic intake to a risk reduction. The recently finished EU-sponsored SynCan project, of which Orafti was an industrial partner, was the focus of two presentation with Dr. Beatrice Pool-Zobel from the Friedrich-Schiller University of Jean reviewing the animal data, and Dr. Kevin Collins from University College Cork presenting the results of a human study on the reduction of colorectal cancer risk by inulin-type fructans.
A symbiotic supplement comprising Orafti's Synergy1 (12 grams per day) and a probiotic (Lactobacillus GG and Bifidobacteria12) was given to 80 people (43 with colonic polyps, 37 with colon cancer) in a double-blind placebo-controlled design for 12 weeks.
The SynCan project found that the symbiotic preparation "clearly demonstrated a functional effect," said Dr. Pool-Zobel, and Dr. Collins reported that the synbiotics appeared to work by altering the intestinal microflora, reducing in vivo genotoxic damage, and changing gene expression in both the polyp and cancer groups.
Professor Gibson confirmed that the mechanisms behind many of the potential health benefits are contentious, and Professor Walker confirmed that pressing a priority for the subject was to "sort out the mechanism."
The majority of the studies have used Orafti's Beneo range, particularly Synergy1, and this is due to Orafti's conviction that "science is key," said Dr. Anne Franck, executive vice president, science and technology.
NutraIngredients.com will review tomorrow the science presented in Boston concerning satiety, immune system modulation, and other newer areas of research reporting potential health benefits of inulin and oligofructose prebiotics.
Stephen Daniells' attendance at the Orafti 5th Research Conference in Boston was partially sponsored by Orafti.