The Pure Probiotic Initiative: Probiotic Potency Testing

By Kelly Heim, Ph.D.

Probiotics offer a broad range of health benefits. As with any supplement, the efficacy of a probiotic depends on dosage. Recommending an adequate dose for an individual patient requires clear knowledge of the potency of a product. While potency of other supplements, such as vitamins, minerals and botanicals can be clearly labeled by familiar weight units, such as milligrams or grams, probiotic potency must specify only viable cells. Confidence in the accuracy of this number is essential for successful and consistent clinical results.^‡

Enumeration of bacteria has been a routine practice in microbiology for over 100 years. The gold-standard method, known as viable plate count, is used throughout the scientific community and industry for exclusive quantification of live bacteria. In this method, a known weight of probiotic material is suspended in culture, applied to a nutrient plate, and incubated. Each living cell develops into a single, discrete colony that is visible to the naked eye. A colony, technically referred to as a colony forming unit (CFU), is equal to one viable cell. Repetition of this test with multiple samples and plates maximizes accuracy. On probiotic labels, results are expressed in CFU per serving.^‡

Since probiotic cells are sensitive to their environment, potency is subject to change. Therefore, potency must be determined after manufacturing, shipping and storage. At Pure Encapsulations, independent laboratories verify potency of all incoming probiotic material. After manufacturing, each batch of finished product is tested. Testing is conducted after the samples have been shipped to a laboratory, ensuring that the potency is validated after transport.^‡

Potency refers to the number of viable cells at a single point in time. An equally important descriptor of probiotic quality is stability, which refers to the retention of potency during manufacturing, shipping, and storage. An imperative step during product development at Pure Encapsulations is analyzing strain-specific stability data for all prospective ingredients. More importantly, the storage stability of finished products is confirmed on an ongoing basis. Independent laboratories have validated label claim potency at the date of expiration for all probiotic products.^‡

Pure Encapsulations’ probiotic manufacturing process involves rigorous control of environmental conditions to maintain the viability of delicate organisms at every step. Guaranteed potency and stability are made possible by this extensive commitment to quality assurance, ensuring confidence in each label and delivery of clinically reliable potencies with every finished product.^‡