Three novel dehydrated wheat/rice cereal functional products with an addition of well documented probiotic Bifidobacterium animalis ssp. lactis BB-12® (BB-12®) were developed in Podravka factory for the infants older than 4 months: instant rice cereal, instant rice cereal with fruits and instant wheat cereal with vanilla. Notably, the number of viable BB-12® cells in each of the novel products was higher than the required minimal number of probiotic cells per gram of product (106 CFU/g) during the storage period of 106 weeks. Therefore, BB-12® strain recovery and genome stability were evaluated by strain-specific polimerase chain reaction and amplified fragment length polymorphism fingerprinting analysis. Further aim was to evaluate the influence of these three different cereal food matrices on specific probiotic properties of BB-12® strain in vitro. Applied food matrices positively influenced the survival in the simulated conditions of the gastrointestinal tract and antagonistic activity against undesirable microorganisms, while no influence on auto- and coaggregation ability of B. animalis ssp. lactis BB-12® was observed. Adhesion to extracellular matrix proteins and intestinal epithelial Caco-2 cells together with antibacterial activity emphasized competitive pathogen exclusion from Caco-2 cells by probiotic strain BB-12®.

Although rare, the ability to produce surface S-layer proteins is beneficially associated with particular Lactobacillus strains being investigated as probiotics. Therefore, this work aimed to study specific probiotic functionalities of selected Levilactobacillus brevis strains MB1, MB2, MB13 and MB20, isolated from human milk microbiota, and to assess the contribution of S-proteins. Firstly, Rapid Annotation using Subsystem Technology revealed that cell wall-related genes were abundant in analysed L. brevis genomes. Furthermore, the results demonstrated that S-proteins mediate aggregation capacity and competitive exclusion of selected pathogens by L. brevis strains. The improvement of Caco-2 epithelial monolayer barrier function was demonstrated by the increase in JAM-A and occludin expressions when L. brevis strains or S-proteins were added, with the effect being most pronounced after treatment with MB2 and S-proteins of MB1. L. brevis strains, especially MB20, exerted the potential to adhere to recombinant human ZG16. Strain MB2 and MB20-S-proteins improved the barrier function of HT29 epithelial monolayer, as evidenced by increased ZG16 expression. Analysed L. brevis strains and S-proteins differentially affected the protein expression of IL-1β, IL-6 and IL-8, and IL-10 cytokines. The most prominent effect was observed by S-proteins of MB20, since IL-1β production was decreased while IL-10 production was significantly increased.

Necrotizing enterocolitis (NEC) is a frequent and severe life-threatening disease affecting the gastrointestinal tract of preterm infants. Given that NEC occurs in a well-defined population of patients, there might be a considerable benefit in identifying specific pharmacological and nutritional preventive strategies, that could reduce the incidence of NEC. Amongst nutritional strategies emphasis has been put on the use of probiotics. Therefore, the aim of this review is to summarize currently available evidence on the role of probiotics in general, as well as the role of specific probiotic strains or their combinations, in the prevention of NEC.