Microbial Variability of Commercial Equine Probiotics.

This research focuses on the inconsistency found between the label claims of commercial equine probiotic products and their actual microbial content. The study unveiled that none of the 11 probiotics tested satisfied their label claims, and most displayed minimal inter-lot variability.

Research Objective and Methodology

• The study was motivated by the fact that previous research reported inconsistencies in the contents of probiotics marketed for animals compared to the claims made on their labels. The gap this study intended to fill was to explore the variability of the same product between different lots, which had not been previously analyzed.
• The goal of this observational study was to evaluate the microbial content and inter-lot variability of commercial equine probiotic products using two different methods: culture-dependent techniques, which require growing the microorganisms in the lab to examine them, and culture-independent techniques, methods that do not require cultures, such as DNA/RNA sequencing.
• Eleven probiotics marketed for horses were scrutinized for their microbial content using both techniques. Subsequently, the found content was then compared to the microorganisms listed and their respective quantities on the product labels.
• A Kruskal-Wallis test, a statistical method used to assess the statistical significance of differences between groups, was used in the analysis.

Findings

• The study’s principal finding was that none of the eleven tested probiotics entirely satisfied their label claims. This finding implies that the listed microbial quantity or presence was not accurate when the probiotics were investigated using both culture-dependent and independent techniques.
• Continuing, nine of the eleven probiotics did not show statistically significant inter-lot variability. In normal terms, this means that the microbial content did not significantly differ between different lots of the same product.
• A comprehensive finding was that several products were lacking in the claimed presence of microorganisms, evident in both culture and polymerase chain reaction (PCR) analyses. PCR is a technique used to amplify selected sections of DNA for further study. Such a result can be a cause for concern, given that the health benefits conferred by probiotics stem from the presence of live microorganisms.