Search

Osteoporosis (OP) is a common metabolic bone disease characterized by low bone mass and microstructural deterioration of bone. Changes in the composition and structure of gut microbiota (GM) are related to changes of bone mass and bone microstructure. However, the relationship between GM and bone mineral density (BMD) is complex, and data are especially scarce for Chinese Han youth. Therefore, 62 Chinese Han youth participants were recruited. Furthermore, according to the T–score evaluation criteria of the World Health Organization (WHO), we divided the BMD levels of participants into three groups: osteoporosis\BDL, osteopenia\BDM, normal bone density\BDH, and the associations between GM community and BMD groups were conducted. According to alpha and beta diversity analysis, significant differences were found in the microbial richness and composition between groups. The dominant phyla of GM in a cohort of Chinese Han youth were Bacteroidota (50.6%) and Firmicutes (41.6%). Anaerobic microorganisms, such as g_Faecalibacterium and g_Megamonas, account for the largest proportion in the gut, which were mainly Firmicutes phylum. The dominant genera and species in the three BMD groups were g_Prevotella, g_Bacteroides, g_Faecalibacterium, g_Megamonas, s_Prevotella copri, s_unclassified_g_Faecalibacterium, s_unclassified_g_Prevotella, s_unclassified_g_Bacteroides and s_Bacteroides plebeius. g_Faecalibacterium, g_Bacteroides and g_Ruminococcus differed between the BDH and BDL groups as well as between the BDH and BDM groups. LEfSe showed three genus communities and eight species communities were enriched in the three BMD groups, respectively. The associations between microbial relative abundance and T–score was not statistically significant by Spearman and regression analysis. In conclusion, the alpha diversity indexes in the BDH group were higher than in the BDL group, and several taxa were identified that may be the targets for diagnosis and therapy of OP. [ABSTRACT FROM AUTHOR]

The development and utilization of probiotics have many environmental benefits when they are used to replace antibiotics in animal production. In this study, intestinal lactic acid bacteria were isolated from the intestines of Cherry Valley ducks. Probiotic lactic acid bacterial strains were screened for antibacterial activity and tolerance to produce a Lactobacillus spp. mixture. The effects of the compound on the growth performance and intestinal flora of Cherry Valley ducks were studied. Based on the results of the antibacterial activity and tolerance tests, the highly active strains Lactobacillus casei 1.2435, L. salivarius L621, and L. salivarius L4 from the intestines of Cherry Valley ducks were selected. The optimum ratio of L. casei 1.2435, L. salivarius L621, and L. salivarius L4 was 1:1:2, the amount of inoculum used was 1%, and the fermentation time was 14 h. In vivo experiments showed that compared with the control group, the relative abundances of intestinal Lactobacillus and Blautia were significantly increased in the experimental group fed the lactobacilli compound (P < 0.05); the relative abundances of Parabacteroides, [Ruminococcus]_torques_group, and Enterococcus were significantly reduced (P < 0.05), and the growth and development of the dominant intestinal flora were promoted in the Cherry Valley ducks. This study will provide more opportunities for Cherry Valley ducks to choose microecological agents for green and healthy breeding. [ABSTRACT FROM AUTHOR]

Salmonella enteritidis is an important food-borne pathogen. The use of antibiotics is a serious threat to animal and human health, owing to the existence of resistant strains and drug residues. Lactic acid bacteria, as a new alternative to antibiotics, has attracted much attention. In this study, we investigated the antibacterial potential and underlying mechanism of Lactobacillus rhamnosus SQ511 against S. enteritidis ATCC13076. The results revealed that L. rhamnosus SQ511 significantly inhibited S. enteritidis ATCC13076 growth or even caused death. Laser confocal microscopic imaging revealed that the cell-free supernatant (CFS) of L. rhamnosus SQ511 elevated the reactive oxygen species level and bacterial membrane depolarization in S. enteritidis ATCC13076, leading to cell death. Furthermore, L. rhamnosus SQ511 CFS had severely deleterious effects on S. enteritidis ATCC13076, causing membrane destruction and the release of cellular materials. In addition, L. rhamnosus SQ511 CFS significantly reduced the expression of virulence, motility, adhesion, and invasion genes in S. enteritidis ATCC13076 (P < 0.05), and considerably inhibited motility and biofilm formation capacity (P < 0.05). Thus, antimicrobial compounds produced by L. rhamnosus SQ511 strongly inhibited S. enteritidis growth, mobility, biofilm formation, membrane disruption, and reactive oxygen species generation, and regulated virulence-related gene expressions, presenting promising applications as a probiotic agent. [ABSTRACT FROM AUTHOR]

Rearing systems play an important role in animal welfare, health and the composition of the gut microbiome. Therefore, the purpose of this study was to investigate the effects of different rearing systems on the composition and function of cecal microbiota in chickens. The 120-day-old Lohmann hens of cage rearing systems (CRS) and free-range systems (FRS) were studied. The cecal bacterial populations of hens were surveyed by high-throughput sequencing (HTS) of the bacterial 16S rRNA hypervariable region V3–V4 combined with metagenomic sequencing analysis. The 16S rRNA sequencing analysis showed that the cecal microbiota differed between the FRS and CRS. The three most abundant bacteria phyla in the two systems were the Bacteroidetes (> 48%), Firmicutes (> 37%), and Proteobacteria (> 6%), the Deferribacteres (> 2.4%) were found in FRS and almost absent in CRS (< 0.01%). The three most abundant genera were the Bacteroides, Rikenellaceae_RC9, and Faecalibacterium, and we found relative abundance of the Parabacteroides (P < 0.05), Prevotellaceae_Ga6A1 (P < 0.01), unclassified Proteobacteria (P < 0.05), and unclassified Spirochaetaceae (P < 0.01) was greater in FRS, whereas abundance of Faecalibacterium, Ruminococcaceae, and Helicobacter was greater in CRS (P < 0.05). Functional gene classification of metagenomic sequencing suggested that energy production and conversion, carbohydrate transport and metabolism, as well as amino acid transport and metabolism were significantly more abundant in FRS, and we identified a range of antibiotic resistance categories in gut microbes of hens reared under both systems. We confirmed differences in microbe gut composition and function in hens reared using two contrasting systems, and ARGs were also identified in the microbiota of these hens. This work has produced new data for laying hens in different production systems and increased the understanding of intestinal microorganisms in laying hens. [ABSTRACT FROM AUTHOR]