Since the terms was first coined by Glenn Gibson and Marcel Roberfroid in 1995, over a dozen different definitions for prebiotics have appeared in the scientific literature. Therefore, “[a]greement on this [new] definition will reduce misinformation and confusion among consumers and health-care providers, facilitate sensible regulatory approaches, and provide common terminology and scope for future prebiotic research,” stated the experts.
Led by Prof Gibson, the scientific experts agreed that the definition of prebiotics should be changed to: “A substrate that is selectively utilized by host microorganisms conferring a health benefit”.
Main conclusions of the expert panel
Writing in Nature Reviews Gastroenterology & Hepatology, Gibson et al noted that prebiotic administration is not limited to the oral route, but can also apply to administration to other sites, such as the vagina and the skin.
Commenting on the potential health benefits, they noted that these are evolving but currently include: “gastrointestinal tract (for example, inhibition of pathogens, immune stimulation), cardiometabolism (for example, reduction in blood lipid levels, effects upon insulin resistance), mental health (for example, metabolites that influence brain function, energy and cognition) and bone (for example, mineral bioavailability), among others”, they wrote.
On the issue of causality, this can be difficult to prove. “However, a human or animal study showing a change in heath markers or symptoms after a specific influence on the microbial population (that is, a blinded placebo-controlled trial with appropriate exclusion and/or inclusion criteria) then it is reasonable to assume that the two are causally related,” they wrote.
The experts also discussed what kind of compounds can be considered a prebiotic, with the currently established prebiotics are carbohydrate-based (inulin, FOS, GOS, XOS etc). However, substances like polyphenols, conjugated fatty acids derived from polyunsaturated fatty acids (PUFAs), and human milk oligosaccharides (HMOs), may also be considered candidates for prebiotics, if supported by the appropriate science.
Finally, the experts made is that the beneficial health effects of a prebiotic must be confirmed in the target organism, so a claim in humans must be supported by data in humans, while a claim or product positioned for a dog must be supported by data from dogs.
“The use of prebiotics to improve health cannot be, and should not be, viewed in isolation”
“[P]rebiotics have the potential to improve human and animal health and reduce risk of diseases mediated by microbiota aberrations,” wrote the experts. “The field would greatly benefit from research focused on mechanisms of action, characterizing responders or non-responders, understanding how structure relates to function of prebiotic substances and correlating that function to health outputs.
“The use of prebiotics to improve health cannot be, and should not be, viewed in isolation, and will be part of a wider approach for healthy nutrition and lifestyle. The capacity exists for prebiotics to be used therapeutically in the management of disease and to preventively promote health,” they concluded.
Source: Nature Reviews Gastroenterology & Hepatology
2017, published online ahead of print, doi:10.1038/nrgastro.2017.75
“Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics”
Authors: G.R. Gibson, et al.