Probiotic Strain Level Viable Cell Count Using Viability PCR: The Signature of Authenticity in Probiotics

More and more probiotic brands are looking to authenticate their products in order to stand by their stated health claims.

Probiotics exert their health benefits by colonizing and interacting with the host's gut. For this to happen effectively, a certain threshold number of live microorganisms is often required. Many probiotic products often specify a cell count (usually in Colony Forming Units or CFUs) on the label. Clinical studies on probiotics often determine a specific dosage (number of CFUs) that provides health benefits. For a consumer to achieve similar benefits, they need to consume a product that provides a comparable number of viable cells.

As probiotic health benefits are strain-specific, viable count determination at the strain level is vital to ensure the efficacious dose is present in the product.

Manufacturers of probiotic products have a responsibility to ensure and maintain the viable cell count of their products, not only to deliver the promised health benefits but also to uphold regulatory, ethical, and economic standards. The verification of viable cells of the specific strain ensures that the product will deliver the intended health benefits.

Fit for purpose methods are important. While the plate count method has been used for more than 125 years, we recommend viability PCR methods to verify strain level viable cell count. Viability real time PCR (v-PCR) allows for the enumeration of individual strains in a multi-strain product. The ability to achieve enumeration to the strain level in multi-strain blends is important because health benefits are strain specific and dose dependent.

Strain level v-PCR testing provides companies the ability to:

As consumers become more educated about probiotics, there's an increasing demand for transparency and quality. This consumer pressure compels manufacturers to ensure their products meet or exceed label claims.

Over time, the number of live microorganisms in a probiotic product can decrease, especially if stored under unfavorable conditions. Monitoring viable cell counts helps manufacturers assess product stability and assign accurate shelf-lives.

To further assure quality and foster trust, some companies use third-party laboratories to independently test their products for viable cell counts and other quality metrics. Purity-IQ provides 3rd party verification for raw material to finished product in different dosage forms to confirm product quality and ensure regulatory compliance.