Influence of the Growth of Pseudomonas aeruginosa in Milk Fermented by Multispecies Probiotics and Kefir Microbiota

Abstract

Introduction: Probiotics are defined as live microorganisms, which when administered in adequate amounts, confer a health benefit on the host. Health benefits have mainly been demonstrated for specific probiotic strains of the following genera: Lactobacillus, Bifidobacterium, Saccharomyces, Enterococcus, Streptococcus, Pediococcus, Leuconostoc and Bacillus. The human microbiota is getting a lot of attention today and research has already demonstrated that alteration of this microbiota may have far-reaching consequences. One of the possible routes for correcting dysbiosis is by consuming probiotics. Methods: In this research we investigated the influence of potentially pathogenic challenge bacteria Pseudomonas aeruginosa on multispecies probiotic food supplement and kefir microbiota. The probiotics included various strains of the species Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus rhamnosus, Lactobacillus delbrueckii subs, bulgaricus, Lactobacillus plantarum, Lactobacillus lactis subs, lactis, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum, Streptococcus thermophilus, Enterococcus faecium. Samples of 40 mL of milk were prepared with added challenge potentially pathogenic Pseudomonas aeruginosa and 1 mL suspension of multispecies probiotics. All samples were incubated for 4 days. Results and discussion: It was found that both the multispecies probiotic supplement and the kefir microbiota with diverse microbial populations successfully decreased the concentration of challenge potentially pathogenic Pseudomonas aeruginosa for 3 log10 steps. On the other hand the antagonistic effect of the oligospecies probiotics with only three different probiotic species and the monospecies probiotic supplement against P. aeruginosa was not detected. These results show that multispecies microorganisms that create a live communities create a synergistic effect and effective complex interconnecting quorum-sensing regulatory networks that compete with a potentially pathogen bacteria. Conclusions: Although probiotic administration does not permanently modulate the intestinal microbiota, this does not mean that during acute disruption of the sensitive intestinal microbiota balance such as due to antibiotic consumption, transiently present probiotics do not aid the permanent intestinal microbiota in restoring this balance.