Second-generation prebiotics get clinical trial support

The mixture, patented and available commercially from Clasado under the brand name Bimuno, was shown to boost bifidobacteria bacteria populations, compared to another prebiotic supplement and placebo within seven days, according to data published in this month's American Journal of Clinical Nutrition .

"These results are very exciting because they show that bifidobacteria seem to have a high affinity towards this prebiotic," said Professor Glenn Gibson - co-author of the study and head of food microbial sciences at the University of Reading.

"Interestingly, the large gut where these bacteria are found controls around 70 per cent of the body's natural immune function, which helps protect against illness.

Bifidobacteria play a key role in the gut's digestive and immune functions and now we have human evidence that prebiotics, like galacto-oligosaccharides (GOS) directly stimulate these health enhancing bacteria," he added.

The prebiotic looks set to tap into the burgeoning prebiotic market, largely created by three inulin producers, all based in Europe.

Other ingredient manufacturers are increasingly looking to promote the prebiotic effect of their products as evidence suggests that prebiotics could be even more useful than the probiotic bacteria that they feed.

Prebiotic ingredients, or those that boost the growth of beneficial probiotic bacteria in the gut, are worth about €90 million in the European marketplace but are forecast to reach €179.7 million by 2010, according to Frost & Sullivan.

The University of Reading researchers, in collaboration with scientists from the Institute of Food Research, recruited 59 healthy human volunteers and assigned them to consume 15 grams of vegetable fat-filled milk powder (FFMP, Cowbell International, South Africa) with or without a seven gram dose of a commercial GOS (Vivinal GOS, V-GOS, Friesland) or 3.6 or seven grams of the new GOS using beta-galactosidases from Bifidobacterium bifidum NCIMB 41171 (B-GOS) for seven days.

Each intervention was consumed for seven days and followed by a seven day washout period before crossing over to another intervention.

The researchers report that the B-GOS mixture led to significant increases in the bifidobacterial population, compared with the placebo.

Moreover, the seven grams per day dose of B-GOS increased the bifidobacterial population more than the equivalent dose of V-GOS.

They also note a significant link between the dose of B-GOS consumed and the bifidobacteria proportion.

"The novel galactooligosaccharide mixture, as a supplement to the Western diet, exerted a prebiotic and more specifically bifidogenic effect in a dose-response relation in healthy human volunteers at doses of 3.6 and seven grams per day," wrote the researchers.

"Although the 3.6-g dose showed a significant increase in the C. perfringens-histolyticum subgroup, the 7-g/d dose seems to be more preferable because the effect on the C. perfringens-histolyticum subgroup was eliminated and a higher bifidogenic effect was noted," they added.

Tailored prebiotics The study offers an interesting insight into the production of galacto-oligosaccharides with interesting functionality using beta-galactosidase enzymes from different sources.

"Depending on the source of the beta-galactosidase, different synthetic product mixtures are formed," explained the researchers.

"Given that beta-galactosidase enzymes from different microorganisms display differing rate constants for conversion of specific glycosidic linkages, it is anticipated that synthetic mixtures produced through enzymes from probiotic organisms will confer selectivity on those specific probiotics when then fermented by the colonic microflora."

Indeed, the results of the new study showed that enzymes from Bifidobacterium bifidum NCIMB 41171 (B-GOS) produced GOS with a higher bifidogenic effect than than GOS produced using enzymes from Bacillus circulans ATCC 4516.

"This indicates that manufacturing of prebiotic oligosaccharides with higher selectivity toward specific bacterial groups is possible," concluded the researchers.

Second-generation prebiotic

The prebiotic has been hailed as 'second generation', since it not only boosts probiotic bacteria at a group level, but also offers additional functionality by inhibiting the adhesion of 'bad' bacteria to the gut wall.

Co-author of the study, George Tzortzis formerly with the university of Reading and now the R&D manager at Clasado, told NutraIngredients.com: "We have seen that Bimuno is having a better prebiotic effect than inulin and another GOS ingredient that is produced by commercially available beta galactosidase, and that this prebiotic effect is attributed to selective increase of the bifidobacterial proportion as monitored in faecal samples."

"Furthermore, we have seen that one fraction of the Bimuno mixture is acting as decoy oligosaccharide preventing the adhesion and invasion of enteropathogenic E. coli and Salmonella enterica Typhimurium to HT29 epithelial cell ( J. Nutr. 2005, Vol. 135, Pages 1726-1731)."

Bimuno is currently marketed as a food supplement that can be purchased as a finished product in UK.

Tzortzis added that the prebiotic is also available as a branded food ingredient and can already be found in branded products in both the US and Australia.

The study was funded by Clasado.

Source: American Journal of Clinical Nutrition March 2008, Volume 87, Pages 785-791 "Prebiotic evaluation of a novel galacto-oligosaccharide mixture produced by the enzymatic activity of Bifidobacterium bifidum NCIM 41171, in healthy humans: a randomized, double-blind, cross-over, placebo-controlled intervention study" Authors: F. Depeint, G. Tzortzis, J. Vulevic, K. I'Anson, G.R. Gibson