Speaking recently at Probiota 2014 in Amsterdam, event chairman Professor Gregor Reid warned industry and academics that very little is still known about the way in which different species of bacteria contained in many multi-strain products interact with each other - citing evidence from the UK which suggests that many of such multi-strain products are less effective than products containing just a few strains of a single strain.
"The tendency is 'let's have 15 strains' ... 'let's have 28 billion'," commented Reid. "You've got to know what they're doing. Are they really having an impact?"
Reid - who is one of the world’s foremost experts on probiotics, and has chaired the United Nations - World Health Organization Expert Panel and Working Group on Probiotics - reminded delegates and industry members that while it may sound impressive produce products with a high numbers of strains or colony forming units (CFUs), efforts will be wasted if the manufacturer does not know whether the species within the product have any net benefit.
Citing research performed by Professor Glenn Gibson of the University of Reading, he explained that evidence is begining to show that certain strains will inhibit the activity of others, rendering both as useless to the consumer.
"The strains inhibit each other. So what's the point of putting them inside the same container if they inhibit each other?" he questioned.
"Know what you are doing. Know what you are putting together."
The Probiota chairman also advised manufacturers to really think about what they are expecting their product to do, "and then prove that it does it, and that by adding an extra strain it is in fact having an extra effect."
When is a prebiotic not a prebiotic?
Reid also slammed certain areas of the industry for 'misleading the public' by claiming a product contained a prebiotic, when in fact the levels are so low that no benefit would be seen.
He called for companies to stop claiming that products contain 'probiotic with prebiotic' unless there is enough of the ingredient to provide a prebiotic effect.
"If you go in the literature, you need around five grams of GOS [galactooligosaccharides]," he said.
"Anything with 88 milligrams is not a prebiotic," he added - citing an unamed company that had claimed 'probiotic and prebiotc' effect after the inclusion of just 88mg of prebiotic fibres.
"Unless you are putting in enough to have a prebiotic effect, don't call it that," he warned.