In recent years, the supply of dietary supplements with live bacteria has increased significantly. In March 2019, we found nine of these products on the Slovenian market, intended for babies. We examined three different batches of the same product. We used microbiological analyses to check the compliance of the declaration with the actual types of bacteria present in the products and their number. Additional purpose of this study was to compare the results of analyses performed according to the manufacturer's instructions with general protocols. The number of bacteria was determined by the classical method of colony counting on selective media and by flow cytometry, when the producer stated this method. On the declarations, we found some irregularities in the naming of bacteria and the use of the word "probiotic" which is not allowed for dietary supplements in EU. For all products, only the total number of microorganisms was reported, even if there were more strains (3 out of 9 total products). Only one product had a fully appropriate label. In eight products, the number of cfu or viable bacteria was adequate, while in one batch of one product the number of bacteria, determined by flow cytometry, was too low. The presence of labeled bacterial species was checked by MALDI-TOF MS and PCR methods. The MALDI-TOF MS method has proven to be easy and fast, but in some products, we have not succeeded to prove the presence of Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus or Bifidobacterium bifidum. This problem could be solved by examining a larger number of colonies. Three products were also analysed according to the manufacturer's instructions, but there were no differences compared to the general protocols.
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