Optimum Doses and Forms of Selenium Maintaining Reproductive Health via Regulating Homeostasis of Gut Microbiota and Testicular Redox, Inflammation, Cell Proliferation, and Apoptosis in Roosters.

BACKGROUND: There is a U-shaped relationship between dietary selenium (Se) ingestion and optimal sperm quality. OBJECTIVES: This study aimed to investigate the optimal dietary dose and forms of Se for sperm quality of breeder roosters and the relevant mechanisms. METHODS: In experiment 1, 18-wk-old Jingbai laying breeder roosters were fed a Se-deficient base diet (BD, 0.06 mg Se/kg), or the BD + 0.1, 0.2, 0.3, 0.4, 0.5, or 1.0 mg Se/kg for 9 wk. In experiment 2, the roosters were fed the BD or the BD + sodium selenite (SeNa), seleno-yeast (SeY), or Se-nanoparticles (SeNPs) at 0.2 mg Se/kg for 9 wk. RESULTS: In experiment 1, added dietary 0.2 and 0.3 mg Se/kg led to higher sperm motility and lower sperm mortality than the other groups at weeks 5, 7, and/or 9. Furthermore, added dietary 0.2-0.4 mg Se/kg produced better testicular histology and/or lower testicular 8-hydroxy-deoxyguanosine than the other groups. Moreover, integrated testicular transcriptomic and cecal microbiomic analysis revealed that inflammation, cell proliferation, and apoptosis-related genes and bacteria were dysregulated by Se deficiency or excess. In experiment 2, compared with SeNa, SeNPs slightly increased sperm motility throughout the experiment, whereas SeNPs slightly reduced sperm mortality compared with SeY at week 9. Both SeY and SeNPs decreased malondialdehyde in the serum than those of SeNa, and SeNPs led to higher glutathione peroxidase (GPX) and thioredoxin reductase activities and GPX1 and B-cell lymphoma 2 protein concentrations in the testis compared with SeY and SeNa. CONCLUSIONS: The optimal dietary Se dose for reproductive health of breeder roosters is 0.25-0.35 mg Se/kg, and SeNPs displayed better effects on reproductive health than SeNa and SeY in laying breeder roosters. The optimal doses and forms of Se maintain reproductive health of roosters associated with regulation intestinal microbiota homeostasis and/or testicular redox balance, inflammation, cell proliferation, and apoptosis.

Gut microbiota contributes to the development of endometrial glands in gilts during the ovary-dependent period.

BACKGROUND: The hyper-prolificacy Meishan gilts achieved a superior endometrial gland development (EGD) than white crossbred gilts during the ovary-independent period (before 60 d of age). Then, the EGD continues under the management of ovary-derived steroid hormones that regulated by gut microbiota (after 60 d of age). However, whether Meishan gilts' superiority in EGD lasting to the ovary-dependent period (after 60 d of age) and the role of gut microbiota in this period both remain unclear. METHODS: Meishan gilts and Landrace x Yorkshire (LxY) gilts were raised under the same housing and feeding conditions until sexual maturity and then we compared their EGD and gut microbiota. Meanwhile, we transplanted fecal microbiota from Meishan gilts to L×Y gilts to explore the role of gut microbiota in EGD. We sampled plasma every 3 weeks and collected the uterus, ovary, liver, and rectal feces after the sacrifice. We then determined the hormone concentrations and expressions of the EGD-related genes. We also profiled the gut microbiota using 16S rDNA sequencing and metabolites of plasma and liver tissue using untargeted metabolomics. Finally, the correlation analysis and significant test was conducted between FMT-shifted gut microbes and EGD-related indices. RESULTS: Meishan gilts have larger endometrial gland area (P < 0.001), longer uterine horn length (P < 0.01) but lighter uterine horn weight (P < 0.05), a distinctive gut microbiota compared with L×Y gilts. Fecal microbiota transplantation (FMT) increased endometrial gland area (P < 0.01). FMT markedly shifted the metabolite profiles of both liver and plasma, and these differential metabolites enriched in steroid hormone biosynthesis pathway. FMT increased estradiol and insulin-like growth factor 1 but decreased progesterone dynamically. FMT also increased the expression of the EGD-related genes estrogen receptor 1 gene, epithelial cadherin, and forkhead box protein A2. There is a significant correlation between FMT-shifted gut microbes and EGD-related indices. CONCLUSION: Sexually matured Meishan gilts achieved a superior EGD than LxY gilts. Meanwhile, gut microbiota contribute to the EGD potentially via regulating of steroid hormones during the ovary-dependent period.

Dietary glycyl-glutamine supplementation ameliorates intestinal integrity, inflammatory response, and oxidative status in association with the gut microbiota in LPS-challenged piglets.

During weaning transition, mammalian newborns suffer severe enteric infections and thus induced gut microbiota dysbiosis, which in turn aggravates enteric disorder. The synthetic dipeptide glycyl-glutamine (GlyGln) has been used as a diet supplement to improve the weaning transition of newborns. However, the effect of dietary GlyGln supplementation on the gut microbiota of piglets with enteric infection remains unclear. Here, weaned piglets received a basal diet or a basal diet supplemented with 0.25% GlyGln for 3 weeks. Five piglets in each group received an intraperitoneal injection of lipopolysaccharide (LPS) (100 µg per kg BW) (LPS and GlyGln + LPS groups) and meanwhile five piglets in a control group received an intraperitoneal injection of saline (Ctrl group). The results showed that dietary GlyGln supplementation improved the LPS induced inflammation response and damage to the ileum morphology by increasing interleukin 10, tight junction proteins, villus height, and the ratio villus height/crypt depth, but decreasing the crypt depth. For the oxidative status, dietary GlyGln supplementation increased the ileal superoxide dismutase and meanwhile reduced the malondialdehyde and nitric oxide synthase activity (NOS) (total NOS and inducible NOS), compared with that in the LPS group. LPS challenge reduced the diversity of gut microbiota and enriched the facultative anaerobic Escherichia coli. The GlyGln restored alpha diversity and the structure of the gut microbiota by enriching obligate anaerobes and short-chain fatty acid (SCFA)-producing bacteria, including Clostridium, Lachnospira, Phascolarctobacterium, Roseburia, Lachnospiraceae, and Synergistetes. GlyGln enriched the gut microbiota function of carbohydrate metabolism and elevated the ileal SCFA concentrations of propionic acid and butyric acid that had been decreased by the LPS challenge. The beneficial effects of dietary GlyGln supplementation are closely associated with its enriched bacteria and SCFAs. Taken together, dietary GlyGln supplementation improved the gut microbiota dysbiosis induced by LPS challenge and enriched obligate anaerobes and SCFA-producing bacteria, which contributed to the amelioration of intestinal integrity, inflammatory responses, and oxidative status.

Anti­inflammatory mechanism of berberine on lipopolysaccharide­induced IEC­18 models based on comparative transcriptomics.

Intestinal surface epithelial cells (IECs) have long been considered as an effective barrier for maintaining water and electrolyte balance, and are involved in the mechanism of nutrient absorption. When intestinal inflammation occurs, it is often accompanied by IEC malfunction. Berberine (BBR) is an isoquinoline alkaloid found in numerous types of medicinal plants, which has been clinically used in China to treat symptoms of gastrointestinal pathogenic bacterial infection, especially bacteria­induced diarrhea and inflammation. In the present study, IEC­18 rat intestinal epithelial cells were treated with lipopolysaccharide (LPS) to establish an in vitro model of epithelial cell inflammation, and the cells were subsequently treated with BBR in order to elucidate the anti­inflammatory mechanism. Transcriptome data were then searched to find the differentially expressed genes (DEGs) compared between two of the treatment groups (namely, the LPS and LPS+BBR groups), and DEGs were analyzed using Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, Weighted Gene Correlation Network Analysis and Interactive Pathways Explorer to identify the functions and pathways enriched with DEGs. Finally, reverse transcription­quantitative PCR was used to verify the transcriptome data. These experiments revealed that, comparing between the LPS and LPS+BBR groups, the functions and pathways enriched in DEGs were 'DNA replication', 'cell cycle', 'apoptosis', 'leukocyte migration' and the 'NF­κB and AP­1 pathways'. The results revealed that BBR is able to restrict DNA replication, inhibit the cell cycle and promote apoptosis. It can also inhibit the classic inflammatory pathways, such as those mediated by NF­κB and AP­1, and the expression of various chemokines to prevent the migration of leukocytes. According to transcriptomic data, BBR can exert its anti­inflammatory effects by regulating a variety of cellular physiological activities, including cell cycle, apoptosis, inflammatory pathways and leukocyte migration.

Effects of Cortex Phellodendri extract on post-weaning piglets diarrhoea.

The diarrhoea incidence rate is often high among weaning piglets. In light of the fact that Cortex phellodendri has long been used to treat diarrhoea in China, this study aimed to evaluate the effects of Cortex Phellodendri Extract (CPE) on diarrhoea in weaning piglets and the mechanism behind such effects. In the first trial, 36 diarrhoeal weaning piglets were randomly divided into three groups. The control group was injected with 20 mg oxytetracycline/kg BW, while the two treatment groups were orally administered with 10 mg and 20 mg CPE/kg BW respectively. In the second trial, 96 weaning piglets were randomly divided into two groups. The control group was fed basal diet, while 300 mg CPE/kg BW was added to the diet of the treatment group. The pathogenic bacteria were then isolated and identified from the diarrhoeal faecal samples. Cell adhesion and RT-PCR tests were used to investigate the effect of CPE on the adhesion of pathogenic bacteria to IPEC-J2 cells. 16S rDNA-based high-throughput sequencing was used to analyse faecal microflora. The results showed that CPE reduced the diarrhoea incidence rate (p < 0.05) and diarrhoea index (p < 0.05) compared to control group, and increased the richness and evenness of weaning piglets' gut microbiota. Escherichia coli (E. coil) was identified as the causative organism. Cell adhesion and RT-PCR tests suggested that CPE reduced the adhesion of E. coli to IPEC-J2 cells (p < 0.05) and the expression of fae and faeG gene (p < 0.05) responsible for encoding E. coli fimbriae protein.

Cortex Phellodendri extract's anti-diarrhea effect in mice related to its modification of gut microbiota.

Cortex Phellodendri extract (CPE) has been used in China to treat diarrhea whereas the underlying mechanisms remain poorly understood. Given that dysbiosis of gut microbiota is a potential reason for diarrhea, and that oral CPE has a low absorption rate in intestine, we hypothesized that modification of gut microbiota is an important factor in CPE's anti-diarrhea effect. To test this hypothesis, we established a diarrhea model by challenging post-weaning mice with oral Enterotoxigenic-Escherichia coli (ETEC), and then the mice were treated with two doses of CPE (80 mg/kg bodyweight and 160 mg/kg bodyweight) or the vehicle control (phosphate buffered saline). Diarrhea indices, inflammatory factors, morphology of jejunum, short-chain fatty acids (SCFAs), and serum endocrine were determined. Modification of gut microbiota was analyzed using 16S rDNA high-throughput sequencing. The changes in functional profiles of gut microbiota were predicted using software PICRUSt. We then explored the association between CPE-responding bacteria and the symptoms indices with the spearman's rank correlation coefficient and significance test. Compared with diarrheal mice, CPE decreased Gut/Carcass ratio and water content of stool, increased goblet cell density and villus height/crypt depth of jejunum, as well as decreased inflammatory indices (Tumour Necrosis Factor-α, Myeloperoxidase and Interleukin-1α). CPE shifted the gut microbiota significantly by increasing alpha diversity (observed species, ace, Shannon, and Simpson) and restoring the gut microbiota. CPE increased Firmicutes and decreased Bacteroidetes. The reduced genus Prevotella, Acinetobacter, and Morganella were positively associated with the diarrhea indices, whereas increased genus Odoribacter, Rikenella, and Roseburia were negatively associated with the diarrhea indices. The abundance of carbohydrate metabolism-related gene and SCFAs-producing bacteria were increased, which was evidenced by increased butyric acid and total SCFAs concentration in the caecum. Consequently, endocrine peptides glucagon-like peptide-1, epidermal growth factor, and peptide tyrosine tyrosine in serum were elevated. CONCLUSIONS: CPE shows a shift function on the gut microbiota in alleviating the diarrhea of mice in a dose-dependent manner. In addition, the microbial metabolites SCFAs may mediate CPE's anti-diarrhea effect by enhancing endocrine secretion in mice.

Modulation of Gut Microbial Community and Metabolism by Dietary Glycyl-Glutamine Supplementation May Favor Weaning Transition in Piglets.

Gut microbiota plays a crucial role in diet nutrient metabolism and maintaining host health. The synthetic dipeptides glycyl-glutamine (Gly-Gln) used as diet supplementation to improve the weaning transition of newborns could be metabolized by certain bacteria in vitro. However, the effect of diet Gly-Gln supplementation on gut microbiota in vivo remains largely unknown. 240 piglets at the age of 28 days (day 28) were randomly assigned to two groups that received a basal diet (Ctrl group) or a basal diet supplemented with 0.25% Gly-Gln (Gly-Gln group) for 3 weeks. Five piglets from each group were euthanized for sampling after overnight fasting on day 38 and day 49, respectively. We determined their structure shifts of the gut microbiota using 16S rDNA-based high-throughput sequencing analysis. Microbial metabolites short-chain fatty acids (SCFAs) in the ileum and the colon were determined with high-performance gas chromatography. The concentrations of endocrine peptides including epidermal growth factor, glucagon-like peptide-1, and glucagon-like peptide-2 in ileal mucosa, as well as the serum concentration of interleukin 1 beta, interleukin 6, interleukin 10, and tumor necrosis factor alpha were determined using Enzyme-Linked Immunosorbent Assay. In addition, we also checked the diarrhea ratio, growth performance, and intestinal morphology to assess the favorable effect of dietary Gly-Gln supplementation during the weaning transition. Dietary Gly-Gln supplementation beneficially altered the gut microbiota by increasing bacterial loading, elevating alpha diversity, and increasing the relative abundance of anaerobes and fiber-degrading bacteria (Phylum Fibrobacteres). Accordingly, the microbial metabolites SCFAs in both colon and ileum, as well as the downstream endocrine peptides in the ileum increased. Meanwhile, dietary Gly-Gln's favorable weaning transition was reflected in the increase of growth performance indices and the reduced inflammatory response in a time dependent manner. There were significant correlations among the bacteria which responded to dietary Gly-Gln supplementation and these checked indices. Taken together, dietary Gly-Gln supplementation selectively modulated the gut microbiota, which may favor piglets' weaning-transition. These findings suggest that gut microbiota targeted approaches can be potentially used to improve weaning transition of piglets by dietary functional amino acid.

Standardized Preparation for Fecal Microbiota Transplantation in Pigs.

The intestine of pigs harbors a mass of microorganisms which are essential for intestinal homeostasis and host health. Intestinal microbial disorders induce enteric inflammation and metabolic dysfunction, thereby causing adverse effects on the growth and health of pigs. In the human medicine, fecal microbiota transplantation (FMT), which engrafts the fecal microbiota from a healthy donor into a patient recipient, has shown efficacy in intestinal microbiota restoration. In addition, it has been used widely in therapy for human gastrointestinal diseases, including Clostridium difficile infection, inflammatory bowel diseases, and irritable bowel syndrome. Given that pigs share many similarities with humans, in terms of anatomy, nutritional physiology, and intestinal microbial compositions, FMT may also be used to restore the normal intestinal microbiota of pigs. However, feasible procedures for performing FMT in pigs remains unclear. Here, we summarize a standardized preparation for FMT in pigs by combining the standard methodology for human FMT with pig production. The key issues include the donor selection, fecal material preparation, fecal material transfer, stool bank establishment, and the safety for porcine FMT. Optimal donors should be selected to ensure the efficacy of porcine FMT and reduce the risks of transmitting infectious diseases to recipients during FMT. Preparing for fresh fecal material is highly recommended. Alternatively, frozen fecal suspension can also be prepared as an optimal choice because it is convenient and has similar efficacy. Oral administration of fecal suspension could be an optimal method for porcine fecal material transfer. Furthermore, the dilution ratio of fecal materials and the frequency of fecal material transfer could be adjusted according to practical situations in the pig industry. To meet the potential large-scale requirement in the pig industry, it is important to establish a stool bank to make porcine FMT readily available. Future studies should also focus on providing more robust safety data on FMT to improve the safety and tolerability of the recipient pigs. This standardized preparation for porcine FMT can facilitate the development of microbial targeted therapies and improve the intestinal health of pigs.

Lactobacillus frumenti Facilitates Intestinal Epithelial Barrier Function Maintenance in Early-Weaned Piglets.

Increased intestinal epithelial barrier function damages caused by early weaning stress have adverse effects on swine health and feed utilization efficiency. Probiotics have emerged as the promising antibiotic alternatives used for intestinal barrier function damage prevention. Our previous data showed that Lactobacillus frumenti was identified as a predominant Lactobacillus in the intestinal microbiota of weaned piglets. However, whether the intestinal epithelial barrier function in piglets was regulated by L. frumenti is still unclear. Here, piglets received a PBS vehicle or PBS suspension (2 ml, 108 CFU/ml) containing the L. frumenti by oral gavage once a day during the period of 6-20 days of age prior to early weaning. Our data demonstrated that oral administration of L. frumenti significantly improved the intestinal mucosal integrity and decreased the serum endotoxin and D-lactic acid levels in early-weaned piglets (26 days of age). The intestinal tight junction proteins (including ZO-1, Occludin, and Claudin-1) were significantly up-regulated by L. frumenti administration. The serum immunoglobulin G (IgG) levels, intestinal secretory immunoglobulin A (sIgA) levels, and interferon-γ (IFN-γ) levels were significantly increased by L. frumenti administration. Furthermore, our data revealed that oral administration of L. frumenti significantly increased the relative abundances of health-promoting microbes (including L. frumenti, Lactobacillus gasseri LA39, Parabacteroides distasonis, and Kazachstania telluris) and decreased the relative abundances of opportunistic pathogens (including Desulfovibrio desulfuricans and Candida humilis). Functional alteration of the intestinal bacterial community by L. frumenti administration was characterized by the significantly increased fatty acids and protein metabolism and decreased diseases-associated metabolic pathways. These findings suggest that L. frumenti facilitates intestinal epithelial barrier function maintenance in early-weaned piglets and may be a promising antibiotic alternative used for intestinal epithelial barrier function damage prevention in mammals.