Established qPCR Method Using Strain-Specific Primers for Enumeration of Paraprobiotic Lactobacillus plantarum L137

Lactobacillus plantarum, extensively present in fermented foods and the human intestinal tract, has numerous health advantages, including regulating systemic immunity, maintaining a balanced intestinal flora, and lowering the risk of tumour progression. Because the health benefits and safety are strain-specific, it is essential to have a trustworthy method for the specific detection and enumeration of L. plantarum L137 to verify probiotic efficacy. The real-time PCR tool was developed using strain-specific primer pairs from the specialized plasmid pLTK2 and successfully validated for specificity, precision, and amplification efficiency. The assay achieved 100% true positive and 0% false positive results by effectively amplifying the target sample and not amplifying any of the six non-target strains. The limit of quantification was established to be 1.7.103 CFU/reaction. The reaction efficiency values were 86.7%, with an R2 value of 0.9864. The repeatability's relative standard deviation (RSD) was 2.34%. The qPCR assay for L. plantarum L137 was found to meet the specific, precise, and efficient requirements. To meet compliance standards, it is crucial to have a reliable and approved assay for strain-specific identification and enumeration for probiotic products.