According to prebiotic specialists at Orafti’s 5th Research Conference at Harvard Medical School, the prebiotics inulin and oligofructose can constitute effective ways of stemming the tide of obesity, or could alter immune responses and protect against potentially harmful infection.
The increasing body of science in these areas looks set to inaugurate new areas to apply prebiotics, with Orafti’s Beneo range leading the way with the quantity of science into the potential health effects.
Additional potential benefits recognized
Prebiotics are non-digestible food products encouraging the growth of "good" bacteria (probiotics) already existing inside the colon. This means that prebiotics work as food for probiotics.
In the past few years, two fructo-oligosaccharide compounds appeared as having very significant prebiotic properties. These compounds, also known as inulin and oligofructose, comprise substrates nourishing the beneficial micro-organisms in the gut.
Significant studies have already concentrated on the role of inulin and oligofructose in bone health and colorectal cancer, and the investigators are now trying to expand in ever-increasing circles to cover potential benefits for the immune system, weight management, and intestinal health.
Belgium’s Orafti has been prominent in building the science behind inulin and oligofructose, and their 5th Research Conference in Boston last week made it possible for the scientists to present old and new data concerning the role of the prebiotics for these new areas of interest.
The study concentrated on inulin (beta (2,1) linear fructans), oligofructose (the partially hydrolyzed product of inulin), or mixtures of the two, most notably Orafti’s Synergy1, a specifically formulated oligofructose-enriched inulin from chicory.
Satiety, weight management and diabetes
Statistics of the occurrence of overweight and obesity within the society are increasingly worrying. Due to this, more and more interest is targeting appetite suppressors or satiety nutrients as a method of controlling weight.
‘According to Orafti, the potential role of inulin and oligofructose in satiety and weight management is extremely relevant’ said Dr Anne Franck, Orafti’s executive vice president, science and technology.
‘It’s the responsibility of the food industry to bring to consumers foods to control weight,’ she explained to NutraIngredients.com.
Preliminary results of animals research have demonstrated that inulin and oligofructose-fed animals have reduced fat mass.
This is associated with the elevated levels of a gut-brain hormone known as glucagon-like peptide one (GLP-1), which improves glucose-stimulated insulin secretion.
Data from animal research of high-fat fed diabetic mice supplemented with inulin and oligofructose for 4 weeks with or without a GLP-1 receptor blocker (exendin 9-39, Ex-9) were presented by Nathalie Delzenne from the Catholic University of Louvain, Belgium, in cooperation with Rémy Burcelin from Rangueil Hospital in Toulouse.
Because of blocking the GLP-1 receptor, the positive effects of the prebiotics on glucose tolerance, such as blood glucose levels, weight gain, and insulin-secretion, prebiotics were interrupted by the administration of Ex-9.
Additional experiments with mice genetically engineered to have the GLP-1 receptor inactivated were completely insensitive to the positive role of inulin and oligofructose.
‘These findings emphasize the potential interest of enhancing endogenous GLP-1 secretion by inulin-type fructans for the prevention and/or treatment of obesity and type-2 diabetes,’ stated Delzenne.
‘Study data in humans are still insufficient, however recent human intervention recent demonstrated promising first evidence for an influence of inulin-type fructans on satiety and food intake regulation,’ explained Prof Furio Brighenti from the University of Parma’s Department of Public Health.
Without a doubt, three human research has been carried out to date with 33, 10 and 11 participants, respectively. All three studies presented effects of inulin and oligofructose on energy consumption and the sensation of fullness.
‘There have been three human studies concerning satiety, and all of them have proven to be very effective’ said a very optimistic Dr Douwina Bosscher, from Orafti.
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) sounded a note of caution, nevertheless, informing this website that satiety may be a ‘tricky marketing thing’ and that some customers may regard it as a ‘quick-fix approach’.
The real answer to obesity, he explained, was to consume less and practice more sports.
Dr Franck acknowledged that this was an area of study where Orafti was determined to do more and said that big human intervention research was intended to begin in not so distant future.
Immune modulation by prebiotics
‘The science of immune modulation is in it’s infancy,’ Dr Franck told NutraIngredients.com.
Despite being early days for the possible benefits in this area, some research has already been published that present a considerable effect of prebiotics in human health. Such an effect is due to influence non-digestible carbohydrates like inulin and oligofructose on metabolic functions in the intestine, which in turn influence local immune cells in this area, and predominantly on the gut-associated lymphoid-tissue, which plays an essential role in the immune system.
Most of the data concerning this area was gathered through experiments on rats and mice, but Dr Bernhard Watzl from the German Federal Research Centre for Nutrition and Food presented unpublished data from pig research, an animal with an intestinal tract similar to humans. The pigs were supplemented short-term (three weeks) and long-term (three months) with inulin and oligofructose (Synergy1) and markers of immune function were measured in a variety of gut immune tissues.
Watzl informed the 160 participants during the conference that short-term supplementation led to increased phagocytic activity of white blood cells and elevated numbers of so-called natural killer T-cells (NKT-cells) in the spleen.
‘In the long-term experiment, the prebiotic stimulated NK cell activity in Peyer’s patches [part of the lymphatic system] and splenocytes [a white blood cell found in the spleen], overall indicating an improvement of innate immunity not only systematically but also locally in the gut,’ he said.
Further study has demonstrated that prebiotics may also improve the response to a vaccination, including research with young children and the measles vaccination. According to Dr Franck, human research looking at the effects of Orafti prebiotics with flu vaccines was set to start.
Inflammatory intestinal conditions
Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) are chronic inflammatory conditions of the intestine striking around 0,5 per cent of the citizens of the Western World. Well-established science has demonstrated that the diseases occur in some people because of a lack of tolerance to gut bacteria. Hence, it is no wonder that prebiotics have appeared as an interesting avenue of research for these diseases and conditions.
Dr Levinus Dieleman from the University of Alberta in Canada told the participants that research has proven that a combination of inulin and oligofructose (Synergy1) was successful in preventing the development of colitis in animals and, when given in along with probiotics, decreased the level of inflammation in a small human trial.
The beneficial effects observed in these experiments were connected with reduced levels of pro-inflammatory cytokines and elevated levels of anti-inflammatory cytokines.
A small human study in patients suffering from Crohn’s disease reported that people receiving a daily supplement of 15g of inulin-type fructans (Prebio1) had lowered disease activity.
According to Dr Frnack, this research provided ‘very nice data’ for the potential of prebiotics in inflammatory intestinal conditions.
Prof Allan Walker from Harvard Medical School told NutraIngredients.com that he was ‘very impressed’ with the findings of the IBD research. Walker stated also that he sees the role of prebiotics as a way of preserving intestinal health, rather than as a method of treatment of IBD. He said that immune suppressors ought to be used in order to get the diseases and conditions under control, and then maintain this, using prebiotics.
