Improving and Comparing Probiotic Plate Count Methods by Analytical Procedure Lifecycle Management.

Probiotics are live microorganisms that confer a health benefit to the host when administered in adequate amounts. This definition links probiotic efficacy to microbial viability. The current gold standard assay for probiotic potency is enumeration using classical microbiology plating-based procedures, yielding results in colony-forming units (CFU). One drawback to plating-based procedures is high variability due to intrinsic and extrinsic uncertainties. These uncertainties make comparison between analytical procedures challenging. In this article, we provide tools to reduce measurement uncertainty and strengthen the reliability of probiotic enumerations by using analytical procedure lifecycle management (APLM). APLM is a tool that uses a step-by-step process to define procedure performance based on the concept that the reportable value (final CFU result) must be fit for its intended use. Once the procedure performance is defined, the information gathered through APLM can be used to evaluate and compare procedures. Here, we discuss the theory behind applying APLM and give practical information about its application to CFU enumeration procedures for probiotics using a simulated example and data set. Data collected in a manufacturer's development laboratory is included to support application of the concept. Implementation of APLM can lead to reduced variability by identifying specific factors (e.g., the dilution step) with significant impact on the variability and providing insights to procedural modifications that lead to process improvement. Understanding and control of the analytical procedure is improved by using these tools. The probiotics industry can confidently apply the information and analytical results generated to make decisions about processes and formulation, including overage requirements. One benefit of this approach is that companies can reduce overage costs. More reliable procedures for viable cell count determinations will improve the quality evaluation of probiotic products, and hence manufacturing procedures, while ensuring that products deliver clinically demonstrated beneficial doses.
Competing Interests: All authors are members of the USP Probiotics Expert Panel. Some authors are employed by companies in the biotherapeutics or probiotics industry: CV and CP are employed by Bacthera and MP is employed by Probiotical Research srl. MW (Consultant), PB (Advanced Microbial Analytics Research Solutions) and JS (Eurofins Microbiology Laboratory) provide services or work for companies that provide services to the biotherapeutics or probiotics industry. VG and BK are employed by the United States Pharmacopeial Convention, which operates in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2021 Weitzel, Vegge, Pane, Goldman, Koshy, Porsby, Burguière and Schoeni.)