Microbial communities inhabiting the breast milk microenvironment are essential in supporting mammary gland health in lactating women and in providing gut-colonizing bacterial 'inoculum' for their ...infants' gastro-intestinal development. Bacterial DNA was extracted from colostrum samples of 45 healthy Slovenian mothers. Characteristics of the communities in the samples were assessed by polymerase chain reaction (PCR) coupled with denaturing gradient gel electrophoresis (DGGE) and by quantitative real-time PCR (qPCR). PCR screening for the prevalence of bacteriocin genes was performed on DNA of culturable and total colostrum bacteria. DGGE profiling revealed the presence of Staphylococcus and Gemella in most of the samples and exposed 4 clusters based on the abundance of 3 bands: Staphylococcus epidermidis/Gemella, Streptococcus oralis/pneumonia and Streptococcus salivarius. Bacilli represented the largest proportion of the communities. High prevalence in samples at relatively low quantities was confirmed by qPCR for enterobacteria (100%), Clostridia (95.6%), Bacteroides-Prevotella group (62.2%) and bifidobacteria (53.3%). Bacterial quantities (genome equivalents ml-1) varied greatly among the samples; Staphylococcus epidermidis and staphylococci varied in the range of 4 logs, streptococci and all bacteria varied in the range of 2 logs, and other researched groups varied in the range of 1 log. The quantity of most bacterial groups was correlated with the amount of all bacteria. The majority of the genus Staphylococcus was represented by the species Staphylococcus epidermidis (on average 61%), and their abundances were linearly correlated. Determinants of salivaricin A, salivaricin B, streptin and cytolysin were found in single samples. This work provides knowledge on the colostrum microbial community composition of healthy lactating Slovenian mothers and reports bacteriocin gene prevalence.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PURPOSE: The purpose of this study was to discover differences in the human fecal microbiota composition driven by long-term omnivore versus vegan/lacto-vegetarian dietary pattern. In addition, the ...possible association of demographic characteristics and dietary habits such as consumption of particular foods with the fecal microbiota was examined. METHODS: This study was conducted on a Slovenian population comprising 31 vegetarian participants (11 lacto-vegetarians and 20 vegans) and 29 omnivore participants. Bacterial DNA was extracted from the frozen fecal samples by Maxwell 16 Tissue DNA Purification Kit (Promega). Relative quantification of selected bacterial groups was performed by real-time PCR. Differences in fecal microbiota composition were evaluated by PCR–DGGE fingerprinting of the V3 16S rRNA region. Participants’ demographic characteristics, dietary habits and health status information were collected through a questionnaire. RESULTS: Vegetarian diet was associated with higher ratio (% of group-specific DNA in relation to all bacterial DNA) of Bacteroides–Prevotella, Bacteroides thetaiotaomicron, Clostridium clostridioforme and Faecalibacterium prausnitzii, but with lower ratio (%) of Clostridium cluster XIVa. Real-time PCR also showed a higher concentration and ratio of Enterobacteriaceae (16S rDNA copies/g and %) in female participants (p < 0.05 and p < 0.01) and decrease in Bifidobacterium with age (p < 0.01). DGGE analysis of the 16S rRNA V3 region showed that relative quantity of DGGE bands from certain bacterial groups was lower (Bifidobacterium, Streptococus, Collinsella and Lachnospiraceae) or higher (Subdoligranulum) among vegetarians, indicating the association of dietary type with bacterial community composition. Sequencing of selected DGGE bands revealed the presence of common representatives of fecal microbiota: Bacteroides, Eubacterium, Faecalibacterium, Ruminococcaceae, Bifidobacterium and Lachnospiraceae. Up to 4 % of variance in microbial community analyzed by DGGE could be explained by the vegetarian type of diet. CONCLUSIONS: Long-term vegetarian diet contributed to quantity and associated bacterial community shifts in fecal microbiota composition. Consumption of foods of animal origin (eggs, red meat, white meat, milk, yoghurt, other dairy products, fish and seafood) and vegetarian type of diet explained the largest share of variance in microbial community structure. Fecal microbiota composition was also associated with participants’ age, gender and body mass.
We conducted a randomized double-blind, placebo-controlled multicentric study to investigate the influence of a synbiotic fermented milk on the fecal microbiota composition of 30 adults with ...irritable bowel syndrome (IBS). The synbiotic product contained Lactobacillus acidophilus La-5, Bifidobacterium animalis ssp. lactis BB-12, Streptococcus thermophilus, and dietary fiber (90% inulin, 10% oligofructose), and a heat-treated fermented milk without probiotic bacteria or dietary fiber served as placebo. Stool samples were collected after a run-in period, a 4-wk consumption period, and a 1-wk follow-up period, and were subjected to real-time PCR and 16S rDNA profiling by next-generation sequencing. After 4wk of synbiotic (11 subjects) or placebo (19 subjects) consumption, a greater increase in DNA specific for L. acidophilus La-5 and Bifidobacterium animalis ssp. lactis was detected in the feces of the synbiotic group compared with the placebo group by quantitative real-time PCR. After 1wk of follow-up, the content of L. acidophilus La-5 and B. animalis ssp. lactis decreased to levels close to initial levels. No significant changes with time or differences between the groups were observed for Lactobacillus, Enterobacteriaceae, Bifidobacterium, or all bacteria. The presence of viable BB-12- and La-5-like bacteria in the feces resulting from the intake of synbiotic product was confirmed by random amplification of polymorphic DNA (RAPD)-PCR. At the end of consumption period, the feces of all subjects assigned to the synbiotic group contained viable bacteria with a BB-12-like RAPD profile, and after 1wk of follow-up, BB-12-like bacteria remained in the feces of 87.5% of these subjects. The presence of La-5-like colonies was observed less frequently (37.5 and 25% of subjects, respectively). Next-generation sequencing of 16S rDNA amplicons revealed that only the percentage of sequences assigned to Strep. thermophilus was temporarily increased in both groups, whereas the global profile of the fecal microbiota of patients was not altered by consumption of the synbiotic or placebo. In conclusion, daily consumption of a synbiotic fermented milk had a short-term effect on the amount and proportion of La-5-like strains and B. animalis ssp. lactis in the fecal microbiome of IBS patients. Furthermore, both synbiotic and placebo products caused a temporary increase in fecal Strep. thermophilus.
The presence of gene determinants for different bacteriocins has been already demonstrated in traditional Slovenian types of raw milk cheeses ‘Tolminc’ and ‘Kraški’. These genes were present also in ...the cultivable microbiota. In this research the aim was to establish how the presence of gene determinants for bacteriocins in microbial consortia is reflected in its antimicrobial activity. In addition, one of the goals was to determine whether the strains that carry gene determinants for bacteriocins have any competitive growth advantage in microbial population. Microbial consortium of ‘Tolminc’ cheese was propagated in milk and examined at the end of propagation its antimicrobial activity and the presence of gene determinants for bacteriocins. Comparison of the results obtained before and after propagation leaded to the conclusion that most of the strains possessing gene determinants for bacteriocins were unable to persist during propagation. The strains which did persist during propagation carried gene determinants for enterocins P, L50B and cytolysin. Antimicrobial activity of consortium before and after propagation was not substantially different and cannot be attributed to any of detected bacteriocins.
The aim of this study was to assess the structure of indigenous microbial community associated with traditional fresh sheep cheese Karakačanski skakutanac and to preserve autochthonousmicrobial ...consortia. Eleven cheeses were sampled during production season (April-September) and subjected to microbiological analysis. Bacterial DNA was isolated by Maxwell®16 DNA system from99 microbial consortia harvested from three culture media (M17, Rogosa, CATC) on the 1st, 2nd and 3rd day of the cheese shelf life. The extracted bulk DNA (n = 99) was used as a template forPCR-ARDRA and PCR-DGGE analysis. There were no dramatic shifts in the bacterial number and structure of the microbial consortia harvested on the 1st, 2nd or 3rd day of the cheese shelf life neitherduring period of sampling. Lactococcus lactis subsp. lactis reached the number of 107-108 CFU g-1, while Leuconostoc pseudomesenteroides, Enterococcus faecalis, and Lactobacillus versmoldensis were identified only at lower dilutions (10-2 - 10-3). This first polyphasic microbiological-molecular study of the Karakačanski skakutanac indicated the main LAB representatives associated with the cheese. Obtained autochthonous microbial consortia present a valuable pool of strains for further genetic and functional characterizations.
Bacteriocin(s) producing lactic acid bacteria naturally present in traditional cheeses represent an inexhaustive pool of microbes with safeguarding potential. Some bacteriocins produced by cheese ...lactic acid bacteria were already described as successful anti-staphylococcal agents. The presence of genes for bacteriocins with potential anti-staphylococcal activity was also demonstrated in two Slovenian traditional raw milk cheeses, “Tolminc” and “Kraški ovčji sir”. Same bacteriocin genes were also detected in viable lactic acid bacteria consortia’s isolated from “bacteriocin positive cheeses” on Rogosa, M17 and CATC agar media. The aim of the research was to elucidate whether or not this particular cheese consortia, in which bacteriocin genes were detected, actually exhibit anti-staphylococcal activity in milk and/or cheese. For this purpose different cheese consortia were selected in relation to versatility of detected bacteriocin genes and used to perform challenge tests against Staphylococcus aureus in milk and cheese. In milk following the time/temperature regime of traditional cheese production all cheese consortia effectively inhibited growth of Staphylococcus aureus in the range of app. 2 to 3 log. In cheese the inhibition of staphylococci was less pronounced but still evident since inhibition of app. 1.5 log was detected. Sole inhibition by lactic acid production was ruled out whilelinking inhibition directly to bacteriocin production would take some additional work.
Sound and timely microbial gut colonization completes newborn's healthy metabolic programming and manifests in infant appropriate growth and weight development. Feces, collected at 3, 30, and 90 days ...after birth from 60 breastfed Slovenian newborns, was submitted to microbial DNA extraction and qPCR quantification of selected gut associated taxa. Multivariate regression analysis was applied to evaluate microbial dynamics with respect to infant demographic, environmental, clinical characteristics and first year growth data. Early microbial variability was marked by the proportion of Bacilli, but diminished and converged in later samples, as bifidobacteria started to prevail. The first month proportions of enterococci were associated with maternity hospital locality and supplementation of breastfeeding with formulae, while Enterococcus faecalis proportion reflected the mode of delivery. Group Bacteroides-Prevotella proportion was associated with infant weight and ponderal index at first month. Infant mixed feeding pattern and health issues within the first month revealed the most profound and extended microbial perturbations. Our findings raise concerns over the ability of the early feeding supplementation to emulate and support the gut microbiota in a way similar to the exclusively breastfed infants. Additionally, practicing supplementation beyond the first month also manifested in higher first year weight and weight gain Z-score.
The purpose of this research was to examine traditional Slovenian ‘Tolminc’ cheese for the presence of lactic acid bacteria that produce several bacteriocins. The presence of gene determinants for ...different bacteriocins in this type of cheese and in the cultivable population of ‘Tolminc’ microbiota, have already been demonstrated, as well as its antimicrobial activity. Due to the difficulties in connecting the presence of gene determinants for bacteriocins with the observed antimicrobial activity it was decided to examine in this study the same features on the level of individual bacteriocinogenic strains. Like in previous results, enterococci and their bacteriocins prevailed in cheese microbial consortia. None of isolated strains inhibited growth of Staphylococcus aureus, while the other indicator strains were inhibited in a strain specific manner. Most of isolated strains carried gene determinants for cytolysin. On the basis of gene determinants for bacteriocins, antimicrobial activity, phenotyping by PhP (PhenePlateTM) system and PCR identification, some similarities found were among Enterococcus isolates.
In this perspective analysis, we strive to answer the following question: how can we advance integrative biology research in the 21st century with lessons from animal science? At the University of ...Ljubljana, Biotechnical Faculty, Department of Animal Science, we share here our three lessons learned in the two decades from 2002 to 2022 that we believe could inform integrative biology, systems science, and animal science scholarship in other countries and geographies. Cultivating multiomics knowledge through a conceptual lens of integrative biology is crucial for life sciences research that can stand the test of diverse biological, clinical, and ecological contexts. Moreover, in an era of the current COVID-19 pandemic, animal nutrition and animal science, and the study of their interactions with human health (and vice versa) through integrative biology approaches hold enormous prospects and significance for systems medicine and ecosystem health.
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