Berman S, Eichelsdoerfer PE, Spicer D, McGann M.

Quality assurance and Lactobacillus-containing dietary supplements commercially available in Washington State.

Bastyr University, 14500 Juanita Dr NE, Kenmore, WA 98028-4966. peichelsdoerfer@bastyr.edu

PURPOSE: Probiotics supplements containing live microorganisms are susceptible to contamination and/or loss of viability during the manufacturing, shipping, and retail storage processes. This investigation evaluated commercially available products for viability, contamination, label accuracy, storage recommendations, and price at the point of purchase by the consumer.

METHODS: Dietary supplement products containing Lactobacillus spp. were purchased from retail and professional settings across Washington State. In addition, a few professional products were purchased directly from the manufacturers following the purchasing procedures used by individual health care practitioners in private practice. Following blinding, products were cultured in duplicate using aseptic technique, then identified to the genus and species level using polymerase chain reaction (PCR) technology by an independent laboratory. Pure cultures of microorganisms known to the investigators were also sent unlabeled for PCR analysis as laboratory controls. PCR results were then compared to manufacturer labeling for accuracy.

RESULTS: The final analysis included 94 useable samples. Of these, 53 (56%) were refrigerated products, and 41 (44%) stored at room temperature. The laboratory correctly identified all control cultures. Eighty-three (88%) samples proved viable. For viable products, culture results matched manufacturer labeling exactly for seven (8%), while 42 (51%) products contained at least one organism that matched labeling at both genus and species level. Seventy-three (88%) products cultured organisms matching labeling at the genus level. Finally, 67 (71%) of products contained at least one organism not listed on the label, and eight (10%) cultured more than one potentially pathogenic organism. The price per minimum daily dose ranged from $0.01 - $3.25.

CONCLUSIONS: Most commercially available Lactobacillus supplement products available in Washington State were viable. A large discrepancy existed between labeling and actual contents as cultured. Refrigerated products were more likely to be viable, however, no correlation was found between price and quality. The most commonly identified labeling discrepancy was at the species level rather than the genus level. Many products contained organisms not listed on the label; some of these could act as human pathogens, posing risk if used by susceptible consumers. Quality losses may have occurred at any of several points between manufacturer and consumer.

 

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