A presentation this month by UAS Laboratories highlighted the different selection criteria that food and supplement manufacturers must consider when choosing strains of the gut friendly bacteria.
Presented at the XXXVII Dairy Industry Conference in Panjim, Goa, the paper provided a break-down of safety, manufacturing, administration and application criteria that must be met for probiotic products to deliver on the benefits that they promise.
Currently, there is no legal definition of the term ‘probiotics’, which has resulted in some products being misleadingly marketed. And with the recent rapid growth of the probiotics market in the US, this puts the industry at danger of shooting itself in the foot.
The science community, trade associations and interested industry members are increasingly stressing the importance of adhering to FAO/WHO definition guidelines in order to maintain the credibility of the category.
Screening potential probiotics
In his paper, Selection Criteria for Probiotics, president and director of research at UAS, Dr S K Dash, said in vitro experiments are the first crucial step to determining whether microorganisms carry potential as probiotic strains. These must then be further validated with animal and human trials, he said.
In vitro tests currently used include: Resistance to gastric acidity; bile acid resistance; adherence to mucus and/or human epithelial cells and cell lines; antimicrobial activity against potentially pathogenic bacteria; ability to reduce pathogen adhesion to surfaces; and bile salt hydrolase activity.
Stability and survival
Dr Dash also highlighted the importance of the stability of probiotics in order to maintain efficacy. “Poor stability discredits the entire category,” he said.
The stability of the microorganisms can be affected by high temperature, oxygen, humidity and high water activity in the culture. Ways in which stability can be enhanced include microencapsulation, nitrogen packaging or other stabilization technology.
In addition, probiotics need to be acid and bile resistant in order to survive in the human body, and must also be resistant to specific conditions in the food products they are incorporated into – such as milk, yogurt, cheese, chocolate and cereal, said Dr Dash.
According to the FAO/WHO, probiotics are defined as "live microorganisms which when administered in adequate amounts confer a health benefit on the host".
However, a lack of regulatory policing means that industry has been left to self-regulate in order to adhere to FAO/Who guidelines.
Labeling recommendations – based on these guidelines – that are encouraged in order to provide consumers with adequate information about the efficacy of probiotic products include:
· Labels should list all microbes, with the genus, species and strain designation. Significantly, the strain designation should not mislead consumers about the functionality of the strain.
· The number of each microbial component should also be given, although this must reflect the count at the end of the product's shelf-life, and not at the time of manufacture.
· Proper storage information should be provided.
· Efficacy claims must also be listed, and these must be truthful and not misleading. They must be based on human studies documenting efficacy of the specific strain in the product, and they must also take into account the impact of the delivery vehicle or additional active ingredients or strains of bacteria.
· Use information must be listed, and this should include recommended consumption level based on levels found efficacious in human studies. The target consumer should also be listed in the case of probiotic supplements, although in the case of probiotic foods and beverages the target consumer is considered to be the general population.
· A product must carry a contact number to report any adverse effects