Flow cytometry as a potential method of measuring bacterial viability in probiotic products: a review

Highlights • A review of flow cytometry for monitoring probiotic culture viability was undertaken. • Flow cytometry had good correlation with plate counts for concentrated fresh cultures. • Sample clean up steps are extremely important to achieve optimal resolution. • Flow cytometry generates multi-parametric data not always reflecting plate counts. • Regulatory definitions of cell viability and cell vitality needs clarification.