Ingredients that support gut health essentially include: Probiotics, or ‘good’ bacteria that improve the balance of intestinal microflora; prebiotics, which are non-digestible food ingredients that encourage the activity of probiotics; synbiotics, a combination of pro- and prebiotics; and fiber, generally defined as carbohydrates that are undigested in the small intestine.
Probiotics
Probiotics, being the more senior of the two in terms of awareness, have had more time than prebiotics to attract a regulatory framework.
The major challenge when it comes to regulating – and marketing – probiotics is the lack of a legal definition for the term. According to the currently adopted definition by FAO/WHO, probiotics are: ‘Live microorganisms which when administered in adequate amounts confer a health benefit on the host’.
In 2002 FAO/WHO set out guidelines that manufacturers to probiotic foods and supplements should adhere to. Minimum criteria include a definition of genus, species and strain, as well as a safety assessment and efficacy research in humans.
To read more about the criteria, click here.
In large, the regulations governing probiotics can be divided up by regions – NutraIngredients will examine those of the United States and Europe.
In the United States, probiotics can be potentially regulated as dietary supplements, GRAS (generally recognized as safe) ingredients, food additives, or drugs, depending how the product is positioned.
To read about the different types of health claims that can be used in the US, click here.
Currently, there are no approved health claims that can be used on probiotic products in the US.
In order petition for a qualified health claim – or health claims that must be accompanied by qualifying language indicating that supporting evidence is limited – it is necessary to conduct an evaluation of the relationship between substance and disease, together with a summary of the scientific data.
A proposed model for the health claims and the scientific data supporting the claims must then be submitted in a dossier to the US Food and Drug Administration (FDA), together with information on adverse effects.
Structure/function claims, which describe the role of a nutrient or ingredient intended to affect normal structure or functions of the human body, do not require pre-market approval from FDA.
However, the ‘burden of proof’ rests with manufacturers, who must have appropriate scientific substantiation to use these claims.
In Europe, probiotics are 'between regulations', generally regulated by the rules pertaining to the products they are incorporated into and the health claims made about those products.
Under the EU's Novel Foods laws – considered by many to be anachronistic – only those probiotic strains that can demonstrate a history of safe use after May 1997 are eligible to remain on the market without Novel Foods approval.
However, the regulatory landscape in the European Union is poised for a sweeping change, with the implementation of new nutrition and health claims legislation.
Passed in January 2007, the legislation requires all health claims to be scientifically assessed by the European Food Safety Authority (EFSA) and passed back to the EC for publication (or rejection) with a final deadline of January 2010.
Numerous probiotic dossiers have been submitted to the European Commission, often relating to individual probiotic strains, and much value is attached to those that are approved.
Indeed, there have been suggestions that claims in the future will be strain-specific, although currently products can note the type of probiotic strain they may contain, but specific health claims are largely prohibited.
Prebiotics
A prebiotic was first defined in 1995 as a "non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves host health" (Gibson GR, Roberfroid MB, J Nutr 1995;125:1401–12).
There is no legal definition of prebiotic in any food labelling legislation, which means that claims are treated on an individual basis depending on the food and the dose, and are reliant on scientific substantiation.
However, because of the lack of clear legislation, there remains inconsistency in what is currently classified as prebiotic, and the level of supporting science.
Currently, the leading prebiotics are considered to be fructo-oligosaccharides (FOS) – inulin – galacto-oligosaccharides (GOS), and lactulose. Although other components such oligosaccharides and some fibres are marketed as prebiotics, they do not carry the same scientific backing, and so are not consistently recognized as such.
Prebiotics are characterized by:
- Resistance to gastric acidity, hydrolysis by mammalian enzymes and GI absorption
- Fermentation by intestinal microflora
- Selective stimulation of growth and/or activity of intestinal bacteria associated with health and wellbeing
Most fibers meet the first two of these requirements, but only prebiotics meet all three.
According to Professor Glenn Gibson from the University of Reading – who coined the term ‘prebiotics’ – “fiber and prebiotics are distinct in that the latter require selectivity of the gut bacterial fermentation but the former does not.”
The definitive proof of what can be called a prebiotic, he told NutraIngredients, are well conducted human trials with proof of selective fermentation using the best methods available for gut flora determinations - which therefore ought to exploit molecular biology.
There are currently working parties from WHO/FAO and ILSI looking at refining the term ‘prebiotics’, but nothing has been decided as yet.
Tomorrow, NutraIngredients will examine the state of supply for gut health ingredients.