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Non-typhoid Salmonellae are worldwide spread food-borne pathogens that cause diarrhea in humans and animals. Their multi-drug resistances require alternative ways to combat this enteric pathogen. Mono-colonization of a gnotobiotic piglet gastrointestinal tract with commensal lactobacilli Lactobacillus amylovorus and Lactobacillus mucosae and with probiotic E. coli Nissle 1917 and their interference with S. Typhimurium infection was compared. The impact of bacteria and possible protection against infection with Salmonella were evaluated by clinical signs, bacterial translocation, intestinal histology, mRNA expression of villin, claudin-1, claudin-2, and occludin in the ileum and colon, and local intestinal and systemic levels of inflammatory cytokines IL-8, TNF-α, and IL-10. Both lactobacilli colonized the gastrointestinal tract in approximately 100× lower density compare to E. coli Nissle and S. Typhimurium. Neither L. amylovorus nor L. mucosae suppressed the inflammatory reaction caused by the 24 h infection with S. Typhimurium. In contrast, probiotic E. coli Nissle 1917 was able to suppress clinical signs, histopathological changes, the transcriptions of the proteins, and the inductions of the inflammatory cytokines. Future studies are needed to determine whether prebiotic support of the growth of lactobacilli and multistrain lactobacilli inoculum could show higher protective effects.

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The mode of delivery plays a crucial role in infant gastrointestinal tract colonisation, which in the case of caesarean section is characterised by the presence of clostridia and low bifidobacterial counts. Gut colonisation can be modified by probiotics, prebiotics or synbiotics. Human milk oligosaccharides (HMOs) are infant prebiotics that show a bifidogenic effect. Moreover, genome sequencing of Bifidobacterium longum subsp. infantis within the infant microbiome revealed adaptations for milk utilisation. This study aimed to evaluate the synbiotic effect of B. longum subsp. infantis, HMOs and human milk (HM) both in vitro and in vivo (in a humanised mouse model) in the presence of faecal microbiota from infants born by caesarean section. The combination of B. longum and HMOs or HM reduced the clostridia and G-bacteria counts both in vitro and in vivo. The bifidobacterial population in vitro significantly increased and produce high concentrations of acetate and lactate. In vitro competition assays confirmed that the tested bifidobacterial strain is a potential probiotic for infants and, together with HMOs or HM, acts as a synbiotic. It is also able to inhibit potentially pathogenic bacteria. The synbiotic effects identified in vitro were not observed in vivo. However, there was a significant reduction in clostridia counts in both experimental animal groups (HMOs + B. longum and HM + B. longum), and a specific immune response via increased interleukin (IL)-10 and IL-6 production. Animal models do not perfectly mimic human conditions; however, they are essential for testing the safety of functional foods.

Soybean foods forming a substantial part of Asian diet have still more expanded into European diet. Raffinose-series oligosaccharides (RSO) are important constituents of soya beans and they can be found also in soybean products. These oligosaccharides can be considered potentially prebiotic for their capability of influencing the composition of the host’s intestinal microbiota. The aim of the present paper was to determine the oligosaccharide content in various soybean products. Enzymatic assay has been used for the determination of oligosaccharides. RSO have been found in all tested samples and their content varied from 0.66 g per 100 g in soybean beverage to 5.59 g per 100 g in first clear soybean flour. Generally, the highest content of RSO has been detected in soybean flour in the average amount of 4.83 g per 100 g. There was no statistically significant difference observed in the amount of oligosaccharides in all four types of soybean flour (P < 0.01). Considerably high amounts of RSO have been found in sweet soybean bars and textured soy protein. Foods as soybean flour and soybean bar ‘Sójový suk’ seem to be effective natural sources of prebiotic oligosaccharides for humans.

Microbial colonization of the mammalian intestine begins at birth, when from a sterile state a newborn infant is exposed to an external environment rich in various bacterial species. An important group of intestinal bacteria comprises bifidobacteria. Bifidobacteria represent major intestinal microbiota during the breast-feeding period. Animal milk contains all crucial nutrients for babies' intestinal microflora. The aim of our work was to test the influence of different mammalian milk on the growth of bifidobacteria. The growth of seven strains of bifidobacteria in human milk, the colostrum of swine, cow's milk, sheep's milk, and rabbit's milk was tested. Good growth accompanied by the production of lactic acid was observed not only in human milk, but also in the other kinds of milk in all three strains of Bifidobacterium bifidum of different origin. Human milk selectively supported the production of lactic acid of human bifidobacterial isolates, especially the Bifidobacterium bifidum species. The promotion of bifidobacteria by milk is speciesspecific. Human milk contains a key factor for the growth of specific species or strains of human-origin bifidobacteria compared to other kinds of milk. In contrast, some components (maybe lysozyme) of human milk inhibited the growth of Bifidobacterium animalis. Animal-origin strains of bifidobacteria were not able to significantly grow even in milk of animal origin, with the exception of B. animalis subsp. lactis 1,2, which slightly grew in sheep's milk.

Fresh samples of intestinal contents of three wild pigs originating from the Central Bohemia region were examined for the presence of bifidobacterial strains. During the study, we isolated many fructose-6-phosphate phosphoketolase-positive, strictly anaerobic, irregular rod-shaped bacterial isolates. Three of them were preliminarily identified as representing a novel species of the genus Bifidobacterium because their 16S rRNA gene sequence similarity with the closest relatives of thermophilic bifidobacteria (Bifidobacterium boum DSM 20432T, Bifidobacterium thermophilum DSM 20210T, Bifidobacterium thermacidophilumsubsp. porcinum LMG 21689T, Bifidobacterium thermacidophilumsubsp. thermacidophilum DSM 15837T) was in the range of 97.9 - 98.4 %. All three bacterial isolates had identical 16S rRNA, dnaJ1, fusA, gyrB and rplB gene sequences. Isolate RP115T was chosen as a representative of the bacterial group and DNA G+C content (mol%) determination, biochemical tests and analyses of physiological and morphological characteristics, habitat and chemotaxonomic traits (peptidoglycan structure, cellular fatty acids and polar lipids profile) were performed. The DNA-DNA hybridization analyses of RP115T and species representing the group of thermophilic bifidobacteria revealed values in the range from 33 to 53 %. This fact, together with relatively low sequence similarities of particular phylogenetic markers among examined bacterial strains and the phenotyping and chemotaxonomy results obtained, indicated that the evaluated bacterial isolate should be classified as representing a separate taxon within the specific group of thermophilic bifidobacteria. The name Bifidobacterium apri (of boar) sp. nov. has been proposed for the representative strain RP115T (=CCM 8605T=DSM 100238T=LMG 28779T).

Geigerová M., Švejstil R., Skřivanová E., Straková E., Suchý P. (2017): Effect of dietary lupin (Lupinus albus) on the gastrointestinal microbiota composition in broiler chickens and ducks. Czech J. Anim. Sci., 62, 369-376.The purpose of the study was to evaluate the amount of raffinose-series oligosaccharides (RSO) in soybean meal (SBM), whole white lupin seed meal (WLM), sunflower meal (SFM), and rapeseed oil meal (ROM) and to determine whether partial or complete dietary WLM replacement affected the numbers of bacteria in selected groups in the microbiota of broiler chickens and ducks without inducing any weight loss. Total counts of anaerobes, lactobacilli, bifidobacteria, and Escherichia coli in caecal samples from both ducks and broiler chickens, as well as in a crop chyme, in broiler chickens, were determined. Live weights before slaughter were determined. Both broiler chickens and ducks were fed a control diet with SBM (L 0 ) or diet containing 50% or 100% WLM as a substitute for SBM (groups L 50 and L 100 , respectively). In comparison with SBM, WLM contained significantly higher amounts of RSO, and the amounts of oligosaccharides in SFM (1.73 ± 0.26 g/100 g) and ROM (1.79 ± 0.14 g/100 g) were negligible compared to those in WLM (8.26 ± 0.14 g/100 g) and SBM (6.96 ± 0.21 g/100 g). The inclusion of lupin in chicken diets did not significantly affect the monitored bacterial groups in crop chyme, but a complete replacement of SBM with WLM (L 100 group) in chicken diets significantly (P ≤ 0.05) increased the counts of lactobacilli in caecal samples. Partial (L 50 group) and complete (L 100 group) lupin supplementation in the duck diet significantly (P ≤ 0.05) increased counts of lactobacilli and bifidobacteria by at least one order of magnitude. E. coli counts in poultry were not affected by changes in diet. The results of our study indicate that partial dietary replacement of SBM with WLM did not significantly affect the live weight of broiler chickens and ducks, but that complete replacement of SBM with WLM may lead to weight loss.