Bacterial census of poultry intestinal microbiome

cThis study focused on identifying reproducible effects of dietary supplementation with a mannan oligosaccharide (MOS) on the broiler cecal bacterial community structure and function in a commercial production setting. Two separate trials, each with a control and a supplemented group, were carried out in the same commercial location and run concurrently. Approximately 10,000 birds from the same commercial hatchery were mirror imaged into each of four commercial broiler sheds and fed either a control or supplemented diet. Cecal contents were obtained on days 7, 21, and 35 posthatch from 12 randomly caught broilers from each group. Bacterial pyrosequencing was performed on all samples, with approximately 250,000 sequences obtained per treatment per time point. The predominant phyla identified at all three time points in both trials were Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, and Tenericutes, representing >99% of all sequences. MOS supplementation altered the bacterial community composition from 7 days supplementation through 35 days supplementation. Bacteroidetes appeared to be replacing Firmicutes as a result of supplementation, with the most noticeable effects after 35 days. The effects of supplementation were reproducible across both trials. PICRUSt was used to identify differences between the functional potentials of the bacterial communities as a result of MOS supplementation. Using level 3 KEGG ortholog function predictions, differences between control and supplemented groups were observed, with very strong segregation noted on day 35 posthatch in both trials. This indicated that alterations of bacterial communities as a result of MOS are likely to alter the functional capability of the cecum. The gastrointestinal microbiota plays a vital role in nutritional, physiological, and protective functions in animals (1). An understanding and a description of the intestinal microbial communities in broilers are important for the development of new feed additives and the appropriate manipulation of diets to improve broiler performance, health, and welfare (2). The intestinal microbiota has a major impact on the bioavailability and bioactivity of dietary components by consuming, storing, and circulating nutrients effectively, while also impacting the host's ability to resist infection, thereby making an essential contribution to host health and performance (3). Poor intestinal health in poultry is associated with increased susceptibility to infectious disease and colonization by pathogens (4). Bacterial-disease outbreaks impose significant constraints on poultry production, adversely impacting the poultry industry by reducing animal welfare and productivity through disease, poor digestion, and poor nutrient absorption. This, in turn, can lead to significant losses for the farmer and can increase the potential for the contamination of poultry products marketed for human consumption (5).Traditionally, antibiotics have been used in poultry feed at subtherapeutic levels to prevent clinical and subclini...

Section: Resultssupporting

confidence: 77%

Phylogenetic and Functional Alterations in Bacterial Community Compositions in Broiler Ceca as a Result of Mannan Oligosaccharide Supplementation

Corrigan

Leeuw²,

Penaud-Frézet

et al. 2015

“…In the chicken gut, lactobacilli are one of the predominant genera (42). These bacteria have the ability to adhere to the mucosal layers and epithelium, promoting colonization (43,44).…”

Section: Discussionmentioning

confidence: 99%

Effects of Xylo-Oligosaccharides on Broiler Chicken Performance and Microbiota

Maesschalck

Eeckhaut

Maertens³

et al. 2015

183

133

hIn broiler chickens, feed additives, including prebiotics, are widely used to improve gut health and to stimulate performance. Xylo-oligosaccharides (XOS) are hydrolytic degradation products of arabinoxylans that can be fermented by the gut microbiota. In the current study, we aimed to analyze the prebiotic properties of XOS when added to the broiler diet. Administration of XOS to chickens, in addition to a wheat-rye-based diet, significantly improved the feed conversion ratio. XOS significantly increased villus length in the ileum. It also significantly increased numbers of lactobacilli in the colon and Clostridium cluster XIVa in the ceca. Moreover, the number of gene copies encoding the key bacterial enzyme for butyrate production, butyryl-coenzyme A (butyryl-CoA):acetate CoA transferase, was significantly increased in the ceca of chickens administered XOS. In this group of chickens, at the species level, Lactobacillus crispatus and Anaerostipes butyraticus were significantly increased in abundance in the colon and cecum, respectively. In vitro fermentation of XOS revealed cross-feeding between L. crispatus and A. butyraticus. Lactate, produced by L. crispatus during XOS fermentation, was utilized by the butyrate-producing Anaerostipes species. These data show the beneficial effects of XOS on broiler performance when added to the feed, which potentially can be explained by stimulation of butyrate-producing bacteria through cross-feeding of lactate and subsequent effects of butyrate on gastrointestinal function. Cereal fibers are composed of carbohydrate polymers that are resistant to digestion in the small intestines of monogastric animals but are completely or partially fermented in the distal gut, and they are believed to stimulate gut health (1). The main components of the cereal fiber fraction are arabinoxylans (AX), pectins, resistant starch, cellulose, ␤-glucans, and lignin (2). Hydrolytic degradation of the heteropolymer AX results in a mixture of arabinose-substituted xylo-oligosaccharides (arabinoxylan-oligosaccharides) (AXOS) and nonsubstituted xylo-oligosaccharides (XOS) (3). XOS are oligomers consisting of xylose units linked through ␤-(1-4) linkages (4). Selective fermentation of XOS has been shown to induce changes in both the composition and activity of the gastrointestinal microbiota, improving the health and well-being of the host. This suggests that XOS could fulfill the definition of a prebiotic (5). The production of lactate and shortchain fatty acids (SCFA), including butyrate, upon fermentation of XOS, has been confirmed in several in vitro and in vivo studies (3, 6). Lactate can stimulate butyrate production due to crossfeeding between lactate-producing bacteria and lactate-utilizing butyrate-producing bacteria from Clostridium cluster XIVa (7). Butyrate has proven beneficial effects on gastrointestinal function, since it has anti-inflammatory properties, fuels epithelial cells, and increases the intestinal epithelial integrity. In addition, butyrate has been shown to improve growth pe...

“…T he chicken gastrointestinal (GI) tract harbors complex communities of bacteria (1,2). The communities are distributed throughout the GI tract, but due to differences in morphology, functionality, metabolic interactions, and microenvironment, regional heterogeneity in community composition is observed along the different GI segments (2,3).…”

mentioning

confidence: 99%

Bacterial Succession in the Broiler Gastrointestinal Tract

Ranjitkar

Lawley

Tannock

et al. 2016

110

bA feeding trial was performed with broilers receiving a diet of wheat-based feed (WBF), maize-based feed (MBF), or maize-based concentrates supplemented with 15% or 30% crimped kernel maize silage (CKMS-15 or CKMS-30, respectively). The aim of the study was to investigate the bacterial community compositions of the crop, gizzard, ileum, and cecum contents in relation to the feeding strategy and age (8, 15, 22, 25, 29, or 36 days). Among the four dietary treatments, bacterial diversity was analyzed for MBF and CKMS-30 by 454 pyrosequencing of the 16S rRNA gene. Since the diets had no significant influence on bacterial diversity, data were pooled for downstream analysis. With increasing age, a clear succession of bacterial communities and increased bacterial diversity were observed. Lactobacillaceae (belonging mainly to the genus Lactobacillus) represented most of the Firmicutes at all ages and in all segments of the gut except the cecum. The development of a "mature" microbiota in broilers occurred during the period from days 15 to 22. Striking increases in the relative abundances of Lactobacillus salivarius (17 to 36%) and clostridia (11 to 18%), and a concomitant decrease in the relative abundance of Lactobacillus reuteri, were found in the ileum after day 15. The concentration of deconjugated bile salts increased in association with the increased populations of L. salivarius and clostridia. Both L. salivarius and clostridia deconjugate bile acids, and increases in the abundances of these bacteria might be associated with growth reduction and gastrointestinal (GI) disorders occurring in the critical period of broiler life between days 20 and 30.