Microbiota Of Chickens Research Articles

Research advancements on the diversity and host interaction of gut microbiota in chickens.

The maintenance of host health and immune function is heavily dependent on the gut microbiota. However, the precise contribution of individual microbial taxa to regulating the overall functionality of the gut microbiome remains inadequately investigated. Chickens are commonly used as models for studying poultry gut microbiota, with high-throughput 16S rRNA sequencing has emerged as a valuable tool for assessing both its composition and functionality. The interactions between the gut's microbial community and its host significantly influence health outcomes, disease susceptibility, and various mechanisms affecting gastrointestinal function. Despite substantial research efforts, the dynamic nature of this microbial ecosystem has led to inconsistencies in findings related to chicken gut microbiota, which is largely attributed to variations in rearing conditions. Consequently, the interaction between the chickens' gut microflora and its host remains inadequately explored. This review highlights recent advances in understanding these relationships, with a specific focus on microbial composition, diversity, functional mechanisms, and their potential implications for improving poultry production.

Effect of Matrine on growth performance, gut health, and gut microbiota in chickens infected with avian pathogenic Escherichia coli

Avian pathogenic Escherichia coli (APEC) is a major cause of avian colibacillosis. Matrine, a natural component derived from Sophora flavescens, exhibits various pharmacological effects, including anti-inflammatory and antioxidant activities. However, its role in mitigating APEC-induced intestinal damage in chickens remains insufficiently understood. This study aimed to explore the protective effects and potential mechanisms of matrine against APEC-induced intestinal damage. Chickens were administered matrine (10 or 20 mg/kg) from 6 days old for 5 days, followed by an APEC intraperitoneal injection on day 10. After 72 h of APEC infection, tissues were collected for analysis. Results indicated that pretreatment with matrine alleviated the symptoms of APEC infection in chickens, improving survival rates and promoting weight gain. Additionally, pretreatment with matrine reduced the secretion and gene expression of IL-1β, IL-6, and TNF-α in intestinal tissues, while enhancing serum SOD, GSH, and CAT activity, as well as gene expression levels in the intestine. Pretreatment with matrine reduced the levels of TLR4, MyD88, and NF-κB in intestinal tissues. Moreover, pretreatment with matrine ameliorated intestinal inflammation and pathological damage, restoring the expression of ZO-1, Occludin, and MUC2 in the intestine during APEC infection. Furthermore, pretreatment with matrine alleviated gut microbiota dysbiosis by lowering the abundance of harmful bacteria. In summary, matrine alleviated APEC-induced intestinal inflammation and damage, potentially by inhibiting NF-κB signaling pathway and reshaping the gut microbiota. These findings provide promising insights into the prevention and treatment of avian colibacillosis.

Alteration in the Gut Microbiota of Chickens Resistant to Eimeria tenella Infection.

Avian coccidiosis, caused by several species of Eimeria, is a widespread and economically important poultry disease that inflicts severe losses in the poultry industry. Understanding the interplay between Eimeria and gut microbiota is critical for controlling coccidiosis and developing innovative treatments to ensure good poultry health. In the present study, chickens were immunized six times with a low dose of Eimeria tenella, resulting in complete immunity against Eimeria infection. The results of fecal microbiota transplantation showed that the gut microbiota of immunized chickens induced a certain degree of resistance to coccidial infection. To investigate the types of intestinal microbiota involved in the development of resistance to Eimeria, the intestinal contents and fecal samples from both immunized and unimmunized groups were collected for 16S rRNA gene sequencing. The results showed that, at the genus level, the abundance of the Eubacterium coprostanoligenes group, Erysipelatoclostridium, Shuttleworthia, and Colidextribacter was significantly increased in the intestinal content of immunized chickens, whereas the abundance of Eisenbergiella was significantly decreased. In fecal samples, the abundance of Clostridiaceae and Muribaculaceae significantly increased, whereas that of Bacillales significantly decreased. These findings will help to elucidate the interactions between E. tenella and the gut microbiota of chickens, providing a basis for isolating E. tenella-resistant strains from the gut microbiome and developing new vaccines against coccidiosis.

Optimization of Poultry Physiological Condition in the Post-Antibiotic Era through Nutritional Intervention – A Review

The intestinal microbe population has a considerable impact on the physiological state of poultry. Nutritional intervention can be used to enhance the equilibrium of the gut microbiota in chickens, leading to good physiological effects. Various nutritional interventions have been implemented, including feed additives, vitamins, and fermented and functional feeds. While numerous studies have shown the efficacy of nutritional strategies, others have noted the variability of these interventions on poultry’s physiological state. Various factors can influence the effectiveness of nutritional interventions on the physiological conditions of poultry, such as the types of feed additives or active components, duration and method of administration, feed composition, environmental conditions during rearing, quality of day-old-chick, type and age of poultry, hygiene, infection, stress, and other related variables. Feed additives, when combined with nutritional components or other active chemicals, can have synergistic and complementary effects. These impacts could improve the effectiveness and reliability of the nutritional interventions on physiological parameters and poultry productivity. Furthermore, combinations can include feed additives or active components like probiotics and acidifiers, probiotics and enzymes, phytobiotics and enzymes, and plant-based materials and chitosan. The combinations show synergistic and complementary benefits, improving physiological conditions in chickens more than using feed additives or active substances alone. Overall, nutritional intervention can be used to improve the microbial balance in poultry intestines and boost their physiological state. Moreover, integrating feed additives with other active components might enhance the physiological circumstances of chickens due to the synergistic effect produced by their combination.

The effects of a high-flavonoid corn cultivar on the gastrointestinal tract microbiota in chickens undergoing necrotic enteritis.

The search for alternative therapies to antimicrobial growth promoters (AGP) in poultry production has gained momentum in the past years because of consumer preference and government restrictions on the use of AGP in animal production. Flavonoids are plant-derived metabolites that have been studied for their health-promoting properties that could potentially be used as an alternative to AGP in poultry. In a previous study, we showed that the inclusion of a flavonoid-rich corn cultivar (PennHFD1) in the diet improved the health of broilers undergoing necrotic enteritis. However, the mechanisms of action by which the PennHFD1-based diet ameliorated necrotic enteritis are unknown. This study describes the microbial diversity and composition of the jejunum and ileum of chickens co-infected with Eimeria maxima and Clostridium perfringens and treated with a high-flavonoid corn-based diet. Luminal content and mucosal samples from the jejunum and ileum were collected for DNA extraction, 16S rRNA amplicon sequencing and data analyses. The infection model and the dietary treatments significantly changed the alfa diversity indices (Mucosal samples: ASVs, P = 0.04; Luminal content samples: ASVs, P = 0.03), and beta diversities (Mucosal samples: P < 0.01, Luminal content: P < 0.01) of the ileal samples but not those of the jejunal samples. The microbial composition revealed that birds fed the high-flavonoid corn diet had a lower relative abundance of C. perfringens compared to birds fed the commercial corn diet. The treatments also changed the relative abundance of other bacteria that are related to gut health, such as Lactobacillus. We concluded that both the infection model and the dietary high-flavonoid corn changed the broilers' gut microbial diversity and composition. In addition, the decrease in the relative abundance of C. perfringens corroborates with a decrease in mortality and intestinal lesions due to necrotic enteritis. Collecting different segments and sample types provided a broader understanding of the changes in the gut microbiota among treatments.

Infectious bronchitis virus vaccination, but not the presence of XCR1, is correlated with large differences in chicken caecal microbiota.

The chicken immune system and microbiota play vital roles in maintaining gut homeostasis and protecting against pathogens. In mammals, XCR1+ conventional dendritic cells (cDCs) are located in the gut-draining lymph nodes and play a major role in gut homeostasis. These cDCs sample antigens in the gut luminal contents and limit the inflammatory response to gut commensal microbes by generating appropriate regulatory and effector T-cell responses. We hypothesized that these cells play similar roles in sustaining gut homeostasis in chickens, and that chickens lacking XCR1 were likely to contain a dysbiotic caecal microbiota. Here we compare the caecal microbiota of chickens that were either heterozygous or homozygous XCR1 knockouts, that had or had not been vaccinated for infectious bronchitis virus (IBV). We used short-read (Illumina) and long-read (PacBio HiFi) metagenomic sequencing to reconstruct 670 high-quality, strain-level metagenome assembled genomes. We found no significant differences between alpha diversity or the abundance of specific microbial taxa between genotypes. However, IBV vaccination was found to correlate with significant differences in the richness and beta diversity of the microbiota, and to the abundance of 40 bacterial genera. In conclusion, we found that a lack of XCR1 was not correlated with significant changes in the chicken microbiota, but IBV vaccination was.

Microbiome and Microbial Pure Culture Study Reveal Commensal Microorganisms Alleviate Salmonella enterica Serovar Pullorum Infection in Chickens.

Pullorum disease, an intestinal disease in chickens caused by Salmonella enterica serovar pullorum (S. Pullorum), is a significant threat to the poultry industry and results in substantial economic losses. The bacteria's transmission, both vertical and horizontal, makes it difficult to completely eliminate it. Control strategies for pullorum disease primarily involve stringent eradication programs that cull infected birds and employ antibiotics for treatment. However, eradication programs are costly, and antibiotic use is restricted. Therefore, developing alternative control strategies is essential. Increasingly, studies are focusing on modulating the gut microbiota to control intestinal diseases. Modulating the chicken gut microbiota may offer a novel strategy for preventing and controlling pullorum disease in poultry. However, the impact of S. Pullorum on the chicken gut microbiota has not been well established, prompting our exploration of the relationship between S. Pullorum and the chicken gut microbiota in this study. In this study, we initially analyzed the dynamic distribution of the gut microbiota in chickens infected with S. Pullorum. Alpha diversity analysis revealed a decrease in observed OTUs and the Shannon diversity index in the infected group, suggesting a reduction in the richness of the chicken gut microbiota due to S. Pullorum infection. Principal coordinate analysis (PCoA) showed distinct clusters between the gut microbiota of infected and uninfected groups, indicating S. Pullorum infection changed the chicken gut microbiota structure. Specifically, S. Pullorum infection enriched the relative abundance of the genera Escherichia-Shigella (65% in infected vs. 40.6% in uninfected groups) and Enterococcus (10.8% vs. 3.7%) while reducing the abundance of Lactobacillus (9.9% vs. 32%) in the chicken microbiota. Additionally, based on the observed changes in the chicken gut microbiota, we isolated microorganisms, including Bifidobacterium pseudolongum, Streptococcus equi and Lacticaseibacillus paracasei (L. paracasei), which were decreased by S. Pullorum infection. Notably, the L. paracasei Lp02 strain was found to effectively inhibit S. Pullorum proliferation in vitro and alleviate its infection in vivo. We found that S. Pullorum infection reduced the richness of the chicken gut microbiota and enriched the relative abundance of the genera Escherichia-Shigella and Enterococcus while decreasing the abundance of the anaerobic genus Lactobacillus. Furthermore, microbiota analysis enabled the isolation of several antimicrobial microorganisms from healthy chicken feces, with a L. paracasei strain notably inhibiting S. Pullorum proliferation in vitro and alleviating its infection in vivo. Overall, this research enhances our understanding of the interaction between gut microbiota and pathogen infection, as well as offers new perspectives and strategies for modulating the chicken gut microbiota to control pullorum disease.

Hawthorn-leaf flavonoid alleviate intestinal health and microbial dysbiosis problems induced by glyphosate

Glyphosate is the active ingredient in the herbicide (i.e., Roundup, Touchdown and Erasure), the safety of which has become a social concern. Hawthorn-leaf flavonoid (HF) possesses various biological functions, including antioxidant, regulating lipid metabolism and intestinal microbiota. Whether HF could reduce the health risk of pure glyphosate to birds remain unknown. The experiment aimed to evaluate the effects of pure glyphosate (25 mg/kg added to water) on the intestinal health and microbiota of chicks and the protective roles of HF (60 mg/kg added to the diet). Exposure to glyphosate decreased growth performance, ileal morphology structure, and antioxidant capacity, and increased the serum level of lipid and pro-inflammatory factors. 16S rRNA sequencing indicated that glyphosate decreased bacterial richness and the abundance of Lactobacillus, and increased proportions of pathogens in the ileum. Metabolomic results revealed that glyphosate increased the level of the cholic acid and fatty acids in the ileac digesta. Meanwhile, glyphosate down-regulated the protein expression associated with lipid transport, antioxidant and tight junction in the ileal mucosal tissue, and up-regulated the pro-inflammatory, oxidative stress proteins. However, dietary HF supplementation effectively mitigated the adverse effects of glyphosate and improved intestinal health of chicks. Therefore, dietary HF can ameliorate the harmful effects of glyphosate on birds, which highlights the potential application of HF in reducing the health risks.

Effect of High Dietary Iron on Fat Deposition and Gut Microbiota in Chickens.

To meet the demand of consumers for chicken products, poultry breeders have made improvements to chickens. However, this has led to a new problem in the modern poultry industry, namely excessive fat deposition. This study aims to understand the effects of dietary iron supplementation on fat deposition and gut microbiota in chickens. In this study, we investigated the effects of iron on the growth performance, fat deposition, and gut microbiota of silky fowl black-bone chickens. A total of 75 7-week-old silky fowl black-bone chickens were randomly divided into three groups (five replicates per group, five chickens per replicate) and fed them for 28 days using a growing diet (control group), a growing diet + 10% tallow (high-fat diet group, HFD group), and a growing diet + 10% tallow + 500 mg/kg iron (HFDFe500 group), respectively. We detected the effects of iron on the growth performance, fat deposition, and gut microbiota of silky fowl black-bone chickens using the growth performance index test, oil red O staining, and HE staining, and found that the high-fat diet significantly increased liver and serum fat deposition and liver injury, while the addition of iron to the diet could reduce the fat deposition caused by the high-fat diet and alleviate liver injury. In addition, 16S rDNA sequencing was used to compare the relative abundance of gut microbiota in the cecal contents in different feeding groups. The results showed that the high-fat diet could induce gut microbiota imbalance in chickens, while the high-iron diet reversed the gut microbiota imbalance. PICRUSt functional prediction analysis showed that dietary iron supplementation affected amino acid metabolism, energy metabolism, cofactors, and vitamin metabolism pathways. In addition, correlation analysis showed that TG was significantly associated with Firmicutes and Actinobacteriota (p < 0.05). Overall, these results revealed high dietary iron (500 mg/kg) could reduce fat deposition and affect the gut microbiota of silky fowl black-bone chickens, suggesting that iron may regulate fat deposition by influencing the gut microbiota of chickens and provides a potential avenue that prevents excessive fat deposition in chickens by adding iron to the diet.

In Vivo Expression of Chicken Gut Anaerobes Identifies Carbohydrate- or Amino Acid-Utilising, Motile or Type VI Secretion System-Expressing Bacteria.

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.

Variations in seminal microbiota and their functional implications in chickens adapted to high-altitude environments

Seminal fluid, once believed to be sterile, is now recognized as constituting a complex and dynamic environment inhabited by a diverse community of micro-organisms. However, research on the seminal microbiota in chickens is limited, and microbiota variations among different chicken breeds remain largely unexplored. In this study, we collected semen samples from Beijing You Chicken (BYC) and Tibetan Chicken (TC) and explored the characteristics of the microbiota using 16S rRNA gene sequencing. Additionally, we collected cloacal samples from the TC to control for environmental contamination. The results revealed that the microbial communities in the semen were significantly different from those in the cloaca. Firmicutes and Actinobacteriota were the predominant phyla in BYC and TC semen, respectively, with Lactobacillus and Phyllobacterium being the dominant genera in each group. Additionally, the seminal microbiota of BYC exhibited greater richness and evenness than that of TC. Principal coordinate analysis (PCoA) indicated significant intergroup differences between the seminal microbiotas of BYC and TC. Subsequently, by combining linear discriminant analysis effect size and random forest analyses, we identified Lactobacillus as the predominant microorganism in BYC semen, whereas Phyllobacterium dominated in TC semen. Furthermore, co-occurrence network analysis revealed a more intricate network in the BYC group than in the TC group. Additionally, unique microbial functional characteristics were observed in each breed, with TC exhibiting metabolic features potentially associated with their ability to adapt to high-altitude environments. The results of this study emphasized the unique microbiota present in chicken semen, which may be influenced by genetics and evolutionary history. Significant variations were observed between low-altitude and high-altitude breeds, highlighting the breed-specific implications of the seminal microbiota for reproduction and high-altitude adaptation.

Isolation and Identification of Chicken-Derived Lactic Acid Bacteria: In Vitro Probiotic Properties and Antagonistic Effects against Salmonella pullorum, Staphylococcus aureus, and Escherichia coli.

The development of probiotics capable of quickly colonizing the intestines of animals is important in promoting the healthy growth of livestock. The aim of this study was to screen lactic acid bacteria (LAB) from the intestinal microbiota of chickens with potential applications, and to evaluate their probiotic properties and antagonistic abilities against Salmonella pullorum, Staphylococcus aureus, and Escherichia coli. The results showed that a total of 79 strains with the characteristics of LAB were isolated from the chicken cecum microbiota, of which 7 strains exhibited strong inhibitory activity against S. pullorum, S. aureus, and E. coli. Performing 16s rDNA sequencing revealed that these seven strains were Lactiplantibacillus pentosus (n = 1), Lactiplantibacillus plantarum (n = 3), Lactiplantibacillus paraplantarum (n = 1), Lactiplantibacillus argentoratensis (n = 1), and Lactiplantibacillus fabifermentans (n = 1). Among them, L. pentosus R26 and L. plantarum R32 exhibited superior antibacterial activity. These two strains demonstrated high lactic acid production ability, with survival rates of 86.29% and 87.99% after 3 h of treatment at pH 1.5, 86.66% and 85.52% after 3 h of treatment with 0.5% bile salts, 90.03% and 88.16% after 2 h of treatment with simulated gastric fluid, and 98.92% and 98.22% after 2 h of treatment with simulated intestinal fluid, respectively. Co-cultivation with L. pentosus R26 for 24 h resulted in 50% of the pathogens being antagonized, while almost complete inhibition was observed following 72 h of co-cultivation. In conclusion, L. pentosus R26 and L. plantarum R32 exhibited high antibacterial activity and acid production capability, while also demonstrating satisfactory tolerance to low pH values and high concentrations of bile salts and digestive fluid. The probiotic characteristics and stress resistance of L. pentosus R26 were slightly superior to those of L. plantarum R32, indicating its potential for development as a probiotic.

Time series of chicken stool metagenomics and egg metabolomics in changing production systems: preliminary insights from a proof-of-concept

BackgroundDifferent production systems of livestock animals influence various factors, including the gut microbiota.MethodsWe investigated whether changing the conditions from barns to free-range chicken farming impacts the microbiome over the course of three weeks. We compared the stool microbiota of chicken from industrial barns after introducing them either in community or separately to a free-range environment.ResultsOver the six time points, 12 taxa—mostly lactobacilli—changed significantly. As expected, the former barn chicken cohort carries more resistances to common antibiotics. These, however, remained positive over the observed period. At the end of the study, we collected eggs and compared metabolomic profiles of the egg white and yolk to profiles of eggs from commercial suppliers. Here, we observed significant differences between commercial and fresh collected eggs as well as differences between the former barn chicken and free-range chicken.ConclusionOur data indicate that the gut microbiota can undergo alterations over time in response to changes in production systems. These changes subsequently exert an influence on the metabolites found in the eggs. The preliminary results of our proof-of-concept study motivate larger scale observations with more individual chicken and longer observation periods.

Layer chicken microbiota: a comprehensive analysis of spatial and temporal dynamics across all major gut sections

BackgroundThe gut microbiota influences chicken health, welfare, and productivity. A diverse and balanced microbiota has been associated with improved growth, efficient feed utilisation, a well-developed immune system, disease resistance, and stress tolerance in chickens. Previous studies on chicken gut microbiota have predominantly focused on broiler chickens and have usually been limited to one or two sections of the digestive system, under controlled research environments, and often sampled at a single time point. To extend these studies, this investigation examined the microbiota of commercially raised layer chickens across all major gut sections of the digestive system and with regular sampling from rearing to the end of production at 80 weeks. The aim was to build a detailed picture of microbiota development across the entire digestive system of layer chickens and study spatial and temporal dynamics.ResultsThe taxonomic composition of gut microbiota differed significantly between birds in the rearing and production stages, indicating a shift after laying onset. Similar microbiota compositions were observed between proventriculus and gizzard, as well as between jejunum and ileum, likely due to their anatomical proximity. Lactobacillus dominated the upper gut in pullets and the lower gut in older birds. The oesophagus had a high proportion of Proteobacteria, including opportunistic pathogens such as Gallibacterium. Relative abundance of Gallibacterium increased after peak production in multiple gut sections. Aeriscardovia was enriched in the late-lay phase compared to younger birds in multiple gut sections. Age influenced microbial richness and diversity in different organs. The upper gut showed decreased diversity over time, possibly influenced by dietary changes, while the lower gut, specifically cecum and colon, displayed increased richness as birds matured. However, age-related changes were inconsistent across all organs, suggesting the influence of organ-specific factors in microbiota maturation.ConclusionAddressing a gap in previous research, this study explored the microbiota across all major gut sections and tracked their dynamics from rearing to the end of the production cycle in commercially raised layer chickens. This study provides a comprehensive understanding of microbiota structure and development which help to develop targeted strategies to optimise gut health and overall productivity in poultry production.

Microencapsulated Sodium Butyrate Alleviates Immune Injury and Intestinal Problems Caused by Clostridium Perfringens through Gut Microbiota.

Microencapsulated sodium butyrate (MS-SB) is an effective sodium butyrate additive which can reduce the release of sodium butyrate (SB) in the fore gastrointestinal tract. In this study, we assess the protective effects and mechanisms of MS-SB in Clostridium perfringens (C. perfringens)-challenged broilers. Broiler chickens were pre-treated with SB or MS-SB for 56 days and then challenged with C. perfringens three times. Our results indicate that the addition of MS-SB or SB before C. perfringens infection significantly decreased the thymus index (p < 0.05). Serum IgA, IgY, and IgM concentrations were significantly increased (p < 0.05), while pro-inflammatory IL-1β, IL-6, and TNF-α were significantly decreased (p < 0.05) under MS-SB or SB supplementation. Compared with SB, MS-SB presented a stronger performance, with higher IgA content, as well as a lower IL-1β level when normal or C. perfringens-challenged. While C. perfringens challenge significantly decreased the villus height (p < 0.05), MS-SB or SB administration significantly increased the villus height and villus height/crypt depth (V/C ratio) (p < 0.05). Varying degrees of SB or MS-SB increased the concentrations of volatile fatty acids (VFAs) during C. perfringens challenge, where MS-SB presented a stronger performance, as evidenced by the higher content of isovaleric acid and valeric acid. Microbial analysis demonstrated that both SB or MS-SB addition and C. perfringens infection increase variation in the microbiota community. The results also indicate that the proportions of Bacteroides, Faecalibacterium, Clostridia, Ruminococcaceae, Alistipes, and Clostridia were significantly higher in the MS-SB addition group while, at same time, C. perfringens infection increased the abundance of Bacteroides and Alistipes. In summary, dietary supplementation with SB or MS-SB improves the immune status and morphology of intestinal villi, increases the production of VFAs, and modulates cecal microbiota in chickens challenged with C. perfringens. Moreover, MS-SB was more effective than SB with the same supplemental amount.

The intestinal microflora diversity of aboriginal chickens in Jiangxi province, China

Intestinal microbiota can coevolve with host to form symbiotic relationship and be participated in the regulation of host physiological function. At present, there is no clear explanation on the effect of intestinal microflora in Jiangxi aboriginal chickens. Here, we investigated the association between gut microbiota and host genome of Jiangxi local chickens using 16S rRNA sequencing and genome-wide association studies (GWAS). The results showed that the breeds and genders had important effects on the intestinal microbiota of chickens. A total of 28 SNPs in 14 regions of the chicken genome were related to the relative abundance of microorganisms in 5 genera: Clostridium_sensu_stricto_1, Enterococcus, Gallibacterium, Turicibacter, and Rikenellaceae_RC9_gut_group. A total of 17 candidate genes were identified composition of chicken microbiome and show an association between the host genome and the chicken intestinal microbiota, which also unveiled the diversity of intestinal microbes in Jiangxi chickens. Given the correlation between chicken genome and intestinal microbe found in the present study, a new idea for the protection of aboriginal chicken genetic resources in China could be provided.

10-hydroxy-2-decenoic acid alleviates lipopolysaccharide-induced intestinal mucosal injury through anti-inflammatory, antioxidant, and gut microbiota modulation activities in chickens.

This study aimed to investigated the effects of 10-hydroxy-2-decenoic acid (10-HDA) on the growth performance, intestinal barrier, inflammatory response, oxidative stress, and gut microbiota of chickens challenged with lipopolysaccharide (LPS). A total of 240 one-day-old chickens were randomly assigned to five treatment groups: (1) control group (basal diet + saline); (2) LPS group (basal diet + LPS); (3) Chlortetracycline (CTC) group (basal diet containing 75 mg/kg CTC + LPS); (4) 0.1% 10-HDA group (basal diet containing 1 g/kg 10-HDA + LPS); and (5) 0.5% 10-HDA group (basal diet containing 5 g/kg 10-HDA + LPS). All chickens were injected intraperitoneally with 0.5 mg/kg body weight of either LPS or saline at 17, 19, and 21 days of age. The results showed that dietary 10-HDA supplementation attenuated the loss in growth performance caused by the LPS challenge (p < 0.05). 10-HDA effectively alleviated LPS-induced intestinal mucosal injury, as evidenced by reduced bleeding, decreased serum diamine oxidase levels (p < 0.05), and increased villus/crypt ratios of the jejunum and ileum (p < 0.05). Dietary treatment with 0.1% 10-HDA reduced the concentrations of inflammatory cytokines (TNF-α, IL-1β, IL-6; p < 0.05), and increased immunoglobulin (IgA, IgG) and antioxidant enzyme levels (CAT, GSH-px, T-SOD) in the serum of LPS-challenged chickens (p < 0.05). These effects were similar to those observed in the CTC group. Moreover, 0.1% 10-HDA treatment reversed the LPS-induced variations in the mRNA expression of genes related to inflammation, antioxidant capacity, and intestinal tight junctions (p < 0.05). 16S rRNA analysis revealed that 10-HDA supplementation increased the relative abundance of Faecalibacterium and Clostridia_UCG-014 (p < 0.05). Additionally, it decreased the abundance of Clostridia_vadinBB60_group, Eubacterium_nodatum_group, and UC5-1-2E3 (p < 0.05). These changes were correlated with reduced inflammation and improved antioxidant capacity in the LPS-challenged chickens. Collectively, dietary 10-HDA supplementation alleviated LPS-induced intestinal mucosal injury and the loss of growth performance through anti-inflammatory, antioxidant, and gut microbiota modulation activities in chickens. Moreover, 0.1% 10-HDA supplementation had comparable or even better protection for LPS-challenged chickens than supplementation with antibiotics or 0.5% 10-HDA. 10-HDA has the potential to be used as an alternative to antibiotics in protecting the intestinal health and improving the performance of poultry.

Evaluation of dynamic effects of dietary medium-chain monoglycerides on performance, intestinal development and gut microbiota of broilers in large-scale production.

Medium-chain monoglycerides (MG) have been reported to affect the productive performance, gut microbiota and health of broiler chickens reared in ideal experimental conditions at home and abroad. However, the effects of MG on performance, intestinal development and gut microbiota of chickens in large-scale farms during different feed stages remain unknown. The present study was conducted on a modern farm with a total of 12,000 yellow feathered broiler chicks that were randomly allotted to 2 groups (1000 chicks/replicate, 6 replicates/group) for a 70-day trial. The control group (CON group) received a basal diet, and the treated group (MG group) was fed a basal diet containing 300mg/kg mixed MG. The results revealed that dietary MG significantly (P<0.05) increased the body weight and average feed intake, but notably reduced the feed conversion and mortality of chickens in large-scale production during the starter phase. The villus height of the duodenum in the MG group at 1, 2 and 7wk of age increased notably, and the villus height to crypt depth ratio at 1, 2, 5 and 10wk of age was improved. Dietary MG decreased the serum insulin content of chickens at 5, 7 and 10wk of age, and decreased the serum lipopolysaccharide at 3 and 7wk of age. The triglyceride level of chickens at 3, 5 and 10wk of age and the low-density lipoprotein cholesterol level of chickens at 7 and 10wk of age in the MG group decreased notably, while the high-density lipoprotein cholesterol increased significantly. Moreover, MG supplementation selectively increased the relative abundance of genus Bacteroides (family Bacteroidaceae) and Lachnospiraceae_NK4A136_group, but decreased the content of genus Rikenellaceae_RC9_gut_group, Collinsella and family Barnesiellaceae in the cecum of chickens at 3, 7 and 10wk of age. Conclusively, these findings showed that dietary MG notably enhanced chicken performance, health and feed nutrient utilization at early ages by regulating gut microbiota, intestinal development and serum biochemical indices.

Environmental Microplastic Exposure Changes Gut Microbiota in Chickens.

As novel environmental contaminants, MPs exist widely in the environment and accumulate in organisms, which has become a global ecological problem. MP perturbations of organismal physiology and behavior have been extensively recorded in aquatic animals, but the potential effects of MPs on poultry are not well characterized. Here, we explored the adverse effects of MP exposure on the growth performance and gut microbiota of chickens. Results showed that the growth performance of chickens decreased significantly during MP exposure. Additionally, Firmicutes, Bacteroidota, and Proteobacteria were found to be dominant in the gut microbiota of MP-exposed chickens, regardless of health status. Although the types of dominant bacteria did not change, the abundances of some bacteria and the structure of the gut microbiota changed significantly. Compared with the controls, the alpha diversity of gut microbiota in chickens exposed to MPs showed a significant decrease. The results of comparative analyses of bacteria between groups showed that the levels of 1 phyla (Proteobacteria) and 18 genera dramatically decreased, whereas the levels of 1 phyla (Cyanobacteria) and 12 genera dramatically increased, during MP exposure. In summary, this study provides evidence that exposure to MPs has a significant impact on the growth performance and gut microbial composition and structure of chickens, leading to a gut microbial imbalance. This may raise widespread public concern about the health threat caused by MP contamination, which is relevant to the maintenance of environmental quality and protection of poultry health.

Green label marinades: A solution to salmonella and campylobacter in chicken products?

IntroductionThe presence of meat-borne pathogens entering the home remains a concern for consumers, despite advances made in improving antimicrobial interventions and systems within the processing line. Naturally antibacterial food ingredients including citrus juice and essential oils have been proven to inhibit the proliferation of microbial growth with varying success. AimsThis study aims to investigate the antimicrobial and sensory effects of mixtures of essential oils, fruit juices and herbs at established Minimum Inhibitory Concentrations (MICs) for their biopreservative effect on general microbiota of chicken and against chicken challenged with selected pathogenic/surrogate microorganisms. Materials and methodsThree marinade compositions were designed for use on chicken meat; lemon juice, thyme oil and black pepper (M1), lime juice, lemongrass oil and chilli paste (M2), and olive oil, oregano oil, basil oil and garlic paste (M3). These marinades were assessed for antibacterial effects against Salmonella enterica, Campylobacter jejuni and Listeria innocua on marinaded chicken drumsticks stored in aerobic conditions at 4 °C. Consumer tasting sessions were also conducted with a small focus group using selected final marinades. ResultsM1 and M2 were effective at significantly reducing initial pathogen carriage from 6 Log CFU/g to 2 Log CFU/g on refrigerated chicken meat as well as increasing the shelf-life of the product during cold-storage from 2 days to 7 days. However, consumer studies indicate that the flavours these marinades impart to treated products can be strong. ConclusionThese findings indicate that these designed marinades have shown excellent potential to improve food safety as well as shelf-life for the consumer, particularly in settings where food safety is often compromised such as barbecuing or in care settings. However, further recipe optimisation is required to make these marinades acceptable to consumers.