Counting and Identifying Probiotics: From a Systematic Comparison of Three Common Methods to Proposing an Appropriate Method for Identification

Background: The plate count technique had traditionally been used for the determination of viability and counting of probiotic bacteria, which had obvious disadvantages. Efficient tools to identify and count probiotics (alone or in combination) have evolved. Objective: This study aimed to compare two methods of counting and identifying probiotics such as Real-time PCR and flow cytometry, with the culture method and suggest an inexpensive method for the diagnosis of probiotics in dairy products. Methods: Electronic databases such as Scopus, PubMed, and Science Direct were systematically searched, identified, screened, and reviewed from June 2001 to December 2022. Results: This study showed that each technology has its strengths, advantages, and disadvantages, but the Real-time PCR method is more suitable than other methods and can identify and count live cells of probiotics. Conclusion: In conclusion, it should be mentioned that due to the superiority of the Real-time PCR method, we recommend the use of this molecular method, but for more assurance and comparison, several methods can be used to count and correctly identify probiotic strains.