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There are extensive differences in the caecal microbiota of chicks from hatcheries and those inoculated with faecal material from adult hens. Besides differences in microbial composition, the latter chickens are highly resistant to Salmonella Enteritidis challenges, while the former are susceptible. In this study, we tested whether strains from genera Bacteroides, Megamonas, or Megasphaera can increase chicken resistance to Salmonella and Campylobacter jejuni when defined microbial mixtures consisting of these bacterial genera are administered. Mixtures consisting of different species and strains from the above-mentioned genera efficiently colonised the chicken caecum and increased chicken resistance to Salmonella by a factor of 50. The tested mixtures were even more effective in protecting chickens from Salmonella in a seeder model of infection (3–5 log reduction). The tested mixtures partially protected chickens from C. jejuni infection, though the effect was lower than that against Salmonella. The obtained data represent a first step for the development of a new type of probiotics for poultry. [ABSTRACT FROM AUTHOR]

The etiology and mechanisms of autism and autism spectrum disorder (ASD) are not yet fully understood. There is currently no treatment for ASD for providing significant improvement in core symptoms. Recent studies suggest, however, that ASD is associated with gut dysbiosis, indicating that modulation of gut microbiota in children with ASD may thus reduce the manifestation of ASD symptoms. The aim of this pilot study (prospective randomized, double-blinded, placebocontrolled) was to evaluate efficacy of the biological response modifier Juvenil in modulating the microbiome of children with ASD and, in particular, whether Juvenil is able to alleviate the symptoms of ASD. In total, 20 children with ASD and 12 neurotypical children were included in our study. Supplementation of ASD children lasted for three months. To confirm Juvenil’s impact on the gut microbiome, stool samples were collected from all children and the microbiome’s composition was analyzed. This pilot study demonstrated that the gut microbiome of ASD children differed significantly from that of healthy controls and was converted by Juvenil supplementation toward a more neurotypical microbiome that positively modulated children’s autism symptoms. [ABSTRACT FROM AUTHOR]

Complex gut microbiota increases chickens' resistance to enteric pathogens. However, the principles of this phenomenon are not understood in detail. One of the possibilities for how to decipher the role of gut microbiota in chickens' resistance to enteric pathogens is to systematically characterise the gene expression of individual gut microbiota members colonising the chicken caecum. To reach this aim, newly hatched chicks were inoculated with bacterial species whose whole genomic sequence was known. Total protein purified from the chicken caecum was analysed by mass spectrometry, and the obtained spectra were searched against strain-specific protein databases generated from known genomic sequences. Campylobacter jejuni, Phascolarctobacterium sp. and Sutterella massiliensis did not utilise carbohydrates when colonising the chicken caecum. On the other hand, Bacteroides, Mediterranea, Marseilla, Megamonas, Megasphaera, Bifidobacterium, Blautia, Escherichia coli and Succinatimonas fermented carbohydrates. C. jejuni was the only motile bacterium, and Bacteroides mediterraneensis expressed the type VI secretion system. Classification of in vivo expression is key for understanding the role of individual species in complex microbial populations colonising the intestinal tract. Knowledge of the expression of motility, the type VI secretion system, and preference for carbohydrate or amino acid fermentation is important for the selection of bacteria for defined competitive exclusion products. [ABSTRACT FROM AUTHOR]

Horizontal gene transfer (HGT) is a key driver in the evolution of bacterial genomes. The acquisition of genes mediated by HGT may enable bacteria to adapt to ever-changing environmental conditions. Long-term application of antibiotics in intensive agriculture is associated with the dissemination of antibiotic resistance genes among bacteria with the consequences causing public health concern. Commensal farm-animal-associated gut microbiota are considered the reservoir of the resistance genes. Therefore, in this study, we identified known and not-yet characterized mobilized genes originating from chicken and porcine fecal samples using our innovative pipeline followed by network analysis to provide appropriate visualization to support proper interpretation., Competing Interests: The authors declare no conflict of interest.