Xylo-oligosaccharides and virginiamycin differentially modulate gut microbial composition in chickens.
ABSTRACT: BACKGROUND: The emergence and spread of antibiotic resistance in pathogens have led to a restriction on the use of antibiotic growth promoters (AGPs) in animal feed in some countries. The potential negative after-effects of a ban on AGPs could be mitigated by improving animal intestinal health with prebiotic dietary fibers such as xylo-oligosaccharides (XOS). However, the mechanism(s) by which an antibiotic or prebiotic contributes to the health and growth of animals are not well understood. Here, we evaluated XOS and virginiamycin (VIRG)-mediated changes in gut microbiota of broiler chickens using pyrosequencing of the 16S rRNA gene. RESULTS: There was a significant change in the relative abundance of certain bacteria, but the overall microbial diversity was not affected by treatment with either XOS or VIRG. Supplementation of HXOS (2 g XOS/kg diet) increased the proportion of Lactobacillus genus in the cecum, whereas Propionibacterium and Corynebacterium genera were enriched in the ileum of VIRG (16 mg/kg) treated birds. Furthermore, an increase in the cecal concentrations of acetate and propionate was observed in HXOS- and VIRG-fed chickens, respectively. These two groups of birds had better feed conversion efficiencies in comparison with the control group from day 7 to 21. In addition, temporal variations in the gut microbiota were evident in the chickens of different ages. CONCLUSIONS: Treatments with XOS or VIRG modified the relative abundance but not the presence or absence of specific microbial genus. The increase in both Lactobacillus spp. and acetate production in the cecum of HXOS-treated chickens may promote intestinal health.
Project description:Salmonella causes inflammation in infected hosts. Inflammation is a well-characterized defensive mechanism of innate immunity. The recognition and engagement of lipopolysaccharide (LPS) endotoxins in the outer membranes of Salmonella to Toll-like receptor 4 of immune cells (macrophages and dendritic cells) trigger inflammatory responses characterized by secretion of pro-inflammatory cytokines, including TNF-beta, IL-1 and IL-6. These cytokines cause fever, anorexia, bodyweight losses, and catabolism of skeletal muscles and adipose tissues. However, molecular events underlying innate immune responses and metabolic activities during the later stage of inflammation are poorly understood. Additionally, the effects of prebiotics and antibiotics on innate immunity and nutrient metabolism are not yet reported. The objective of this study is to investigate the effects of a mannanoligosaccharide (MOS) prebiotic and virginiamycin (VIRG) sub-therapeutic antibiotic on innate immunity and glucose metabolism during late inflammation. We induced Salmonella LPS-systemic inflammation in a chicken model. Differentially regulated gene expressions were measured using 2 colour focussed oligonucleotide chicken-specific microarrays. Microarray analysis was performed on liver, intestinal and skeletal muscle tissues. We found that late inflammation was principally modulated by interleukin 3 (IL 3) and that glucose was mobilized from gluconeogenesis occurring in the intestines only. MOS and VIRG modulated innate immunity and metabolic genes differently. In contrast to VIRG, MOS terminated inflammatory responses earlier. Our results indicate IL 3 gene up-regulation in VIRG-fed chickens. To meet the higher energy requirements of VIRG chickens, genes for intestinal gluconeogenesis and liver glycolysis were respectively induced. Our study reveals the potential mechanisms by which prebiotic and antibiotic modulated innate immunity and glucose metabolism during late inflammation. 14-day old chickens were injected i.p. with saline or LPS. For each tissue and experimental conditions (saline or LPS challenge), a total of 12 microarrays (6 MOS birds + 6 VIRG birds) were used in a 2 x 2 factorial design and complete interwoven loop arrangement. We compared gene expression from prebiotic-fed birds with antibiotic-fed birds without including reference RNA. LPS challenge, antibiotic or prebiotic, innate immunity, glucose metabolism
Project description:Due to their potential prebiotic properties, arabinoxylan-derived oligosaccharides [(A)XOS] are of great interest as functional food and feed ingredients. While the (A)XOS metabolism of Bifidobacteriaceae has been extensively studied, information regarding lactic acid bacteria (LAB) is still limited in this context. The aim of the present study was to fill this important gap by characterizing candidate (A)XOS hydrolyzing glycoside hydrolases (GHs) identified in the genome of Lactobacillus brevis DSM 20054. Two putative GH family 43 xylosidases (XynB1 and XynB2) and a GH family 43 arabinofuranosidase (Abf3) were heterologously expressed and characterized. While the function of XynB1 remains unclear, XynB2 could efficiently hydrolyze xylooligosaccharides. Abf3 displayed high specific activity for arabinobiose but could not release arabinose from an (A)XOS preparation. However, two previously reported GH 51 arabinofuranosidases from Lb. brevis were able to specifically remove α-1,3-linked arabinofuranosyl residues from arabino-xylooligosaccharides (AXHm3 specificity). These results imply that Lb. brevis is at least genetically equipped with functional enzymes in order to hydrolyze the depolymerization products of (arabino)xylans and arabinans. The distribution of related genes in Lactobacillales genomes indicates that GH 43 and, especially, GH 51 glycosidase genes are rare among LAB and mainly occur in obligately heterofermentative Lactobacillus spp., Pediococcus spp., members of the Leuconostoc/Weissella branch, and Enterococcus spp. Apart from the prebiotic viewpoint, this information also adds new perspectives on the carbohydrate (i.e., pentose-oligomer) metabolism of LAB species involved in the fermentation of hemicellulose-containing substrates.
Project description:This study investigated the effects of xylo-oligosaccharide (XOS) and flavomycin (FLA) on the performance and immune function of broiler chickens. A total of 150 ArborAcres broilers were randomly divided into three groups and fed for six weeks from one day of age in cascade cages. The diets of each test group were (1) a basal diet, (2) the basal diet supplemented with 2 mg/kg FLA, and (3) the basal diet supplemented with 2 mg/kg XOS. At 21 and 42 days, the growth performance index values and short-chain fatty acid (SCFA) concentrations in the cecum were quantified. Furthermore, immunoglobulin G (IgG) and plasma interleukin 2 (IL-2) as well as mRNA expression of LPS-Induced TNF-alpha Factor (LITAF), Toll-like receptor-5 (TLR5) and interferon gamma (IFN? ) in the jejunum were quantified. The results showed that administration of XOS or FLA to chickens significantly improved the average daily gain. Supplementation with XOS increased acetate and butyrate in the cecum, while FLA supplementation increased propionate in the cecum. An increase in plasma IgG was observed in XOS-fed 21-day-old broilers, but FLA supplementation decreased IgG in the plasma of 42-day-old broilers and increased plasma IL-2. Furthermore, FLA or XOS supplementation downregulated mRNA expression of IFN? , LITAF and TLR5. The above data suggest that addition of XOS and FLA to the diet could improve the growth performance of broilers and reduce the expression of cytokine genes by stimulating SCFA.
Project description:In this study, the effects of plant extracts (PEs) and virginiamycin (VIRG) on broiler growth performance, as well as on host intestinal microbiota composition and function were investigated. A total of 288 one-day-old male Cobb broiler chickens were randomly divided into four treatment groups (with six replicates per group). The duodenal, ileal, and cecal content of six broilers per treatment group after 14 and 28 days of treatment were sampled. This material was used for high-throughput Illumina sequencing of the V3-V4 region of the 16S rRNA gene. The results showed that chickens fed 400 mg/kg plant extracts (HPE group) had significantly higher average body weights at day 28 as compared to the control group (CT; P < 0.05), and lower feed-to-meat ratios over days 15-42 (P < 0.01). Within the HPE group at day 14, the relative abundances of two bacterial phyla and 10 bacterial genera increased significantly in the ileal microbiota, and the relative abundance of three bacterial phyla and four bacterial genera decreased. The relative abundance of the genus Lactobacillus in the cecal microbiota decreased from 21.48% (CT group) to 8.41% (fed 200 mg/kg PEs; LPE group), 4.2% (HPE group), and 6.58% (fed 30 mg/kg virginiamycin; VIRG group) after 28 days. In contrast, Faecalibacterium and unclassified Rikenellaceae increased in abundance in the HPE group (from 18 to 28.46% and from 10.83 to 27.63%, respectively), while Bacteroides (36.7%) and Lachnospiraceae increased in abundance in the VIRG group. PICRUSt function analysis showed that the ileal microbiota of the PE treatment groups were more enriched in genes related to the meolism of cofactors and vitamins. In addition, the cecal microbiotas of the LPE and HPE groups were enriched in genes predicted to encode enzymes within 15 and 20 pathways, respectively. These pathways included protein digestion and absorption, amino acid metabolism, lipid biosynthesis, lipopolysaccharide biosynthesis, the citrate cycle (TCA cycle), and lipoic acid metabolism. Similarly, the VIRG group was enriched in 55 metabolic pathways (17 in the duodenum, 18 in the ileum, and 20 in the cecum) on day 28 (P < 0.05). Thus, the results indicated that the observed increase in broiler growth performance after PE or VIRG supplementation might be attributed to an improvement in intestinal microbial composition and metabolic function.
Project description:Synbiotics are synergistic combinations of prebiotics and probiotics. In chickens, synbiotics can be delivered in ovo to expedite colonization of the gut by beneficial bacteria. We therefore aimed to design synbiotics in vitro and validate them in broiler chickens upon in ovo delivery. The probiotic components of the synbiotics were Lactobacillus salivarius and Lactobacillus plantarum. Their growth was assessed in MRS medium supplemented with different prebiotics. Based on in vitro results (hatchability and growth curve), two synbiotics were designed: S1 -Lactobacillus salivarius with galactooligosaccarides (GOS) and S2 -Lactobacillus plantarum with raffinose family oligosaccharides (RFO). These synbiotics were delivered to Cobb broiler chicken embryos on day 12 of incubation at optimized doses (105 cfu egg-1 of probiotic, 2 mg egg-1 of prebiotic). Post hatching, 2,400 roosters were reared (600 individuals group-1 divided into eight replicate pens). Microbial communities were analyzed in ileal and cecal digesta on day 21 using FISH. Gene expression analysis (IL1?, IL4, IL6, IL8, IL12, IL18, IFN?, and IFN?) was performed on days 7, 14, 21, and 42 for the spleen and cecal tonsils with RT-qPCR. Body weight and feed intake of the roosters did not differ by the treatments. Microbial populations of Lactobacillus spp. and Enterococcus spp. in the ileum were higher in S1 and S2 than in the control. In the cecum, the control had the highest bacterial counts. S1 caused significant up-regulation of IL6, IL18, IL1?, IFN?, and IFN? in the spleen on day 21 and IL1? on day 7 (P < 0.05). In cecal tonsils, S1 caused significant down-regulation of IL12, IL8, and IL1? on day 42 and IFN? on day 14 (P < 0.05). S2 did not elicit such patterns in any tissues investigated. Thus, we demonstrate that divergent effects of synbiotics in broiler chickens were reflected in in vitro tests.
Project description:Oyster mushroom waste (OMW) is a by-product of the agriculture industry with valuable antimicrobial, antioxidant, antifungal, and prebiotic properties. This by-product might be a useful alternative to antibiotic growth stimulators in poultry nutrition. The purpose of this research was to test the impact of OMW on the immune responses and on the morphology of intestine of broiler chickens. Four dietary therapies with five replicas of 15 birds in each, totalling 300 day- Ross 308 broiler chickens, were utilized in this study. Control chickens were fed a mixed diet that included a maize-soybean meal complemented by 1 and 2% OMW in addition to the basal diet. Furthermore, Enramycin (125 g/kg) was added to the control diet as an antibiotic. Throughout this experiment, performance was studied as well as the immune response to the Newcastle Disease Virus (NDV) and intestinal morphological traits. A substantial surge was noted in body weight gain (BWG) and feed intake (FI) of chickens after the addition of 1% OMW (p ? 0.05). In contrast, feed supplementation with 2% OMW, compared with the control diet, produced no noteworthy increase in BWG or the feed conversion rate (FCR). Antibiotic addition, on the other hand, increased serum cholesterol (p ? 0.05). After 42 days, neither OMW nor antibiotic addition affected organ mass. In contrast, antibiotic addition reduced the small intestine percentage, crypt depth and villus height (p ? 0.05). The Newcastle disease vaccine (NDV) antibody titer improved after feed supplementation with 1% OMW comparing with the control and antibiotic diet group. Furthermore, OMW supplementation decreased the heterophil-to-lymphocyte H/L ratio (p ? 0.05). The use of OMW led to a reduction in the malondialdehyde (MDA) content of the breast and liver and an increase in glutathione peroxidase. It helped to reduce glutathione, glutathione reductase, and glutathione S-transferase. In conclusion, the impact of OMW were dose-dependent, and the use of 1% OMW in broiler diets enhanced their growth and immunity. Nonetheless, supplementation with 2% OMW produced conflicting results.
Project description:Probiotics can promote the health and growth performance of animals through modulation of intestinal microbiota. When used as a feed additive, they have the potential to minimize or abolish the use of antibiotics. In this study, we investigated the effect of the probiotic strain Bacillus amyloliquefaciens TL on the growth performance and cecum microflora composition in Cobb 500 broiler chickens. In total, 180 broilers were randomly divided into three groups-each group comprised 4 pens, and each pen contained 15 chickens. The three groups were fed either a control diet, or a diet supplemented with either the antibiotic chlortetracycline or B. amyloliquefaciens TL. Broilers were weighed, and cecum contents were collected on days 7, 14, 21, and 35, respectively. The broilers in both the antibiotic and probiotic groups exhibited significant weight gain compared with controls, exhibiting increases of 16.02% and 13.40%, respectively, after 35 days (P < 0.01). Similarly, the feed conversion ratio (FCR, 1-35 days) of broilers in the chlortetracycline and B. amyloliquefaciens TL groups was lower than that of the controls. HiSeq high-throughput sequencing of 16S rRNA of the cecal microbiota was performed on days 7, 14, 21, and 35, respectively. The Firmicutes/Bacteroidetes ratio was higher in the chlortetracycline and B. amyloliquefaciens TL groups than in the control group on days 14, 21, and 35, and especially on day 21. The prevalence of genera Oscillospira, Ruminococcus, Butyricicoccus, and Faecalibacterium (Firmicutes) was higher in the antibiotic and probiotic groups, while that of Bacteroides, Parabacteroides (Bacteroidetes), and Lactobacillus was higher in the control group. In this study, the changes in the microbiota of the probiotic group were similar to those in the antibiotic group. These results suggest that the probiotic strain B. amyloliquefaciens TL can modulate the cecal microbiota of broilers similar to chlortetracycline.
Project description:Prebiotics are defined as food components that confer health benefits on the host through modulation of the microbiota. Xylooligosaccharides (XOS) are non-digestible oligosaccharides that have recently received increasing attention as potential prebiotic candidates. XOS are sugar oligomers composed of 1,4-linked xylopyranosyl backbone and are obtained by either chemical or, more commonly, enzymatic hydrolysis of xylan polysaccharides, extracted from the plant cell wall. The bifidogenic effect of XOS was demonstrated by both in vitro studies and small-scale in vivo human studies. Some intestinal bacterial strains are able to grow on XOS, yet numerous studies have demonstrated that the ability to utilize these oligosaccharides varies considerably among these bacteria. The aim of this study is to investigate the ability of several strains Lactobacillus to use XOS. Fifteen Lactobacillus strains, allifiated to L. plantarum, L. brevis and L. sakei, were studied. Screening procedure was performed for the ability of the strains to utilize XOS as an alternative carbon source. Only some of them utilize XOS. The growth kinetics show the presence of two lag phases, indicating that these bacteria utilize probably some monosaccharides present in the used XOS. XOS were fermented with high specificity by Bifidobacteria strains, but Lactobacilli did not metabolize XOS efficiently.
Project description:This study investigated the effects of a galactooligosaccharide (GOS) prebiotic in ovo injected on intestinal transcriptome and plasma immune parameters of broiler chickens kept under thermoneutral (TN) or heat stress (HS) conditions. Fertilized Ross 308 eggs were injected in ovo with 0.2 mL physiological saline without (control, CON) or with 3.5 mg of GOS (GOS). Three-hundred male chicks/injection treatment (25 birds/pen) were kept in TN or HS (30 °C) conditions during the last growing phase, in a 2 × 2 factorial design. At slaughter, from 20 birds/injection group (half from TN and half from HS), jejunum and cecum were collected for transcriptome analysis, and plasma was collected. No differences in plasma parameters (IgA and IgG, serum amyloid) and no interaction between injection treatment and environment condition were found. GOS-enriched gene sets related to energetic metabolism in jejunum, and to lipid metabolism in cecum, were involved in gut barrier maintenance. A homogeneous reaction to heat stress was determined along the gut, which showed downregulation of the genes related to energy and immunity, irrespective of in ovo treatment. GOS efficacy in counteracting heat stress was scarce after ten days of environmental treatment, but the in ovo supplementation modulates group of genes in jejunum and cecum of broiler chickens.
Project description:The diversity of bacterial floras in the ilea and ceca of chickens that were fed a vegetarian corn-soy broiler diet devoid of feed additives was examined by analysis of 1,230 partial 16S rRNA gene sequences. Nearly 70% of sequences from the ileum were related to those of Lactobacillus, with the majority of the rest being related to Clostridiaceae (11%), Streptococcus (6.5%), and Enterococcus (6.5%). In contrast, Clostridiaceae-related sequences (65%) were the most abundant group detected in the cecum, with the other most abundant sequences being related to Fusobacterium (14%), Lactobacillus (8%), and Bacteroides (5%). Statistical analysis comparing the compositions of the different 16S rRNA libraries revealed that population succession occurred during some sampling periods. The significant differences among cecal libraries at 3 and 7 days of age, at 14 to 28 days of age, and at 49 days of age indicated that successions occurred from a transient community to one of increasing complexity as the birds aged. Similarly, the ileum had a stable bacterial community structure for birds at 7 to 21 days of age and between 21 to 28 days of age, but there was a very unique community structure at 3 and 49 days of age. It was also revealed that the composition of the ileal and cecal libraries did not significantly differ when the birds were 3 days old, and in fact during the first 14 days of age, the cecal microflora was a subset of the ileal microflora. After this time, the ileum and cecum had significantly different library compositions, suggesting that each region developed its own unique bacterial community as the bird matured.