Background Necrotic enteritis(NE)is a major enteric disease in poultry,yet effective mitigation strategies remain elusive.Deoxycholic acid(DCA)and butyrate,two major metabolites derived from the intestinal microbiota,...Background Necrotic enteritis(NE)is a major enteric disease in poultry,yet effective mitigation strategies remain elusive.Deoxycholic acid(DCA)and butyrate,two major metabolites derived from the intestinal microbiota,have independently been shown to induce host defense peptide(HDP)synthesis.However,the potential synergy between these two compounds remains unexplored.Methods To investigate the possible synergistic effect between DCA and butyrate in regulating HDP synthesis and barrier function,we treated chicken HD11 macrophage cells and jejunal explants with DCA and sodium butyrate(NaB),either individually or in combination,for 24 h.Subsequently,we performed RNA isolation and reverse transcrip-tion-quantitative PCR to analyze HDP genes as well as the major genes associated with barrier function.To further determine the synergy between DCA and NaB in enhancing NE resistance,we conducted two independent trials with Cobb broiler chicks.In each trial,the diet was supplemented with DCA or NaB on the day-of-hatch,followed by NE induction through sequential challenges with Eimeria maxima and Clostridium perfringens on d 10 and 14,respectively.We recorded animal mortality after infection and assessed intestinal lesions on d 17.The impact of DCA and NaB on the microbiota in the ileum and cecum was evaluated through bacterial 16S rRNA gene sequencing.Results We found that the combination of DCA and NaB synergistically induced multiple HDP genes in both chicken HD11 cells and jejunal explants.Additionally,the gene for claudin-1,a major tight junction protein,also exhibited synergistic induction in response to DCA and NaB.Furthermore,dietary supplementation with a combination of 0.75 g/kg DCA and 1 g/kg NaB led to a significant improvement in animal survival and a reduction in intestinal lesions compared to either compound alone in a chicken model of NE.Notably,the cecal microbiota of NE-infected chickens showed a marked decrease in SCFA-producing bacteria such as Bacteroides,Faecalibacterium,and Cuneatibacter,with lactobacilli becoming the most dominant species.However,supplementation with DCA and NaB largely restored the intestinal microbiota to healthy levels.Conclusions DCA synergizes with NaB to induce HDP and claudin-1 expression and enhance NE resistance,with potential for further development as cost-effective antibiotic alternatives.展开更多
Background:Intestinal microbiota plays a key role in nutrient digestion and utilization with a profound impact on feed efficiency of livestock animals.However,the intestinal microbes that are critically involved in fe...Background:Intestinal microbiota plays a key role in nutrient digestion and utilization with a profound impact on feed efficiency of livestock animals.However,the intestinal microbes that are critically involved in feed efficiency remain elusive.Methods:To identify intestinal bacteria associated with residual feed intake(RFI)in chickens,male Cobb broiler chicks were individually housed from day 14 to day 35.Individual RFI values were calculated for 56 chickens.Luminal contents were collected from the ileum,cecum,and cloaca of each animal on day 35.Bacterial DNA was isolated and subjected to 16S rRNA gene sequencing.Intestinal microbiota was classified to the feature level using Deblur and QIIME 2.High and low RFI groups were formed by selecting 15 and 17 chickens with the most extreme RFI values for subsequent LEfSe comparison of the difference in the microbiota.Spearman correlation analysis was further performed to identify correlations between the intestinal microbiota composition and RFI.Results:No significant difference in evenness,richness,and overall diversity of the microbiota in the ileum,cecum,or cloaca was observed between high and low RFI chickens.However,LEfSe analysis revealed a number of bacterial features being differentially enriched in either high or low RFI chickens.Spearman correlation analysis further identified many differentially enriched bacterial features to be significantly correlated with RFI(P<0.05).Importantly,not all short-chain fatty acid(SCFA)producers showed a positive association with RFI.While two novel members of Oscillibacter and Butyricicoccus were more abundant in low-RFI,high-efficiency chickens,several other SCFA producers such as Subdoligranulum variabile and two related Peptostreptococcaceae members were negatively associated with feed efficiency.Moreover,a few closely-related Lachnospiraceae family members showed a positive correlation with feed efficiency,while others of the same family displayed an opposite relationship.Conclusions:Our results highlight the complexity of the intestinal microbiota and a need to differentiate the bacteria to the species,subspecies,and even strain levels in order to reveal their true association with feed efficiency.Identification of RFI-associated bacteria provides important leads to manipulate the intestinal microbiota for improving production efficiency,profitability,and sustainability of poultry production.展开更多
Background:Intestinal microbiota is critical for maintaining animal health and homeostasis.However,involvement of the fungal community,also known as the mycobiota,in animal health and disease is poorly understood.This...Background:Intestinal microbiota is critical for maintaining animal health and homeostasis.However,involvement of the fungal community,also known as the mycobiota,in animal health and disease is poorly understood.This study was aimed to examine the association between the intestinal mycobiota and the severity of necrotic enteritis(NE),an economically significant poultry disease.Methods:A total of 90 day-of-hatch Cobb broilers were infected with Eimeria maxima on d 10,followed by an oral challenge with C.perfringens on d 14 to induce NE,while another 10 broilers were served as mock-infected controls.On d 17,the lesions in the jejunum were scored,and the ileal digesta were subjected to DNA isolation and real-time PCR quantification of total bacterial and fungi populations.Internal transcribed spacer 2(ITS2)amplicon sequencing was also performed to profile the ileal mycobiota composition.Changes in the ileal mycobiota in response to NE were investigated.Spearman correlation analysis was further conducted to identify the correlations between relative abundances of individual ileal fungi and the severity of NE.Results:While the total bacterial population in the ileum was increased by 2-to 3-fold in NE chickens,the total fungal population was progressively declined in more exacerbated NE,with the most severely infected chickens showing a nearly 50-fold reduction relative to mock-infected controls.Richness of the ileal mycobiota also tended to reduce in chickens with NE(P=0.06).Compositionally,among 30 most abundant fungal amplicon sequence variants(ASVs),11 were diminished and 7 were enriched(P<0.05),while 12 remained largely unchanged in NEafflicted chickens(P>0.05).Multiple Wallemia and Aspergillus species were markedly diminished in NE(P<0.05)and also showed a significant negative correlation with NE severity(P<0.05).Conclusions:Dysbiosis of the ileal mycobiota is induced evidently by NE and the extent of the dysbiosis is positively correlated with disease severity.These findings suggest a possible role of the intestinal mycobiota in NE pathogenesis and highlight the mycobiota as a new potential target for NE mitigation in poultry.展开更多
基金supported by the USDA National Institute of Food and Agriculture grants (2020-67016-31619 and 2023-67015-39095)the Ralph F. and Leila W. Boulware Endowment Fund+1 种基金Oklahoma Agricultural Experiment Station Project H-3112supported by a USDA National Institute of Food and Agriculture Predoctoral Fellowship grant (2021-67034-35184)
文摘Background Necrotic enteritis(NE)is a major enteric disease in poultry,yet effective mitigation strategies remain elusive.Deoxycholic acid(DCA)and butyrate,two major metabolites derived from the intestinal microbiota,have independently been shown to induce host defense peptide(HDP)synthesis.However,the potential synergy between these two compounds remains unexplored.Methods To investigate the possible synergistic effect between DCA and butyrate in regulating HDP synthesis and barrier function,we treated chicken HD11 macrophage cells and jejunal explants with DCA and sodium butyrate(NaB),either individually or in combination,for 24 h.Subsequently,we performed RNA isolation and reverse transcrip-tion-quantitative PCR to analyze HDP genes as well as the major genes associated with barrier function.To further determine the synergy between DCA and NaB in enhancing NE resistance,we conducted two independent trials with Cobb broiler chicks.In each trial,the diet was supplemented with DCA or NaB on the day-of-hatch,followed by NE induction through sequential challenges with Eimeria maxima and Clostridium perfringens on d 10 and 14,respectively.We recorded animal mortality after infection and assessed intestinal lesions on d 17.The impact of DCA and NaB on the microbiota in the ileum and cecum was evaluated through bacterial 16S rRNA gene sequencing.Results We found that the combination of DCA and NaB synergistically induced multiple HDP genes in both chicken HD11 cells and jejunal explants.Additionally,the gene for claudin-1,a major tight junction protein,also exhibited synergistic induction in response to DCA and NaB.Furthermore,dietary supplementation with a combination of 0.75 g/kg DCA and 1 g/kg NaB led to a significant improvement in animal survival and a reduction in intestinal lesions compared to either compound alone in a chicken model of NE.Notably,the cecal microbiota of NE-infected chickens showed a marked decrease in SCFA-producing bacteria such as Bacteroides,Faecalibacterium,and Cuneatibacter,with lactobacilli becoming the most dominant species.However,supplementation with DCA and NaB largely restored the intestinal microbiota to healthy levels.Conclusions DCA synergizes with NaB to induce HDP and claudin-1 expression and enhance NE resistance,with potential for further development as cost-effective antibiotic alternatives.
基金This work was supported by the USDA National Institute of Food and Agriculture(grant no.2018-68003-27462)the Ralph F.and Leila W.Boulware Endowment Fund,and Oklahoma Agricultural Experiment Station Project H-3025K.A.R.was supported by a USDA-NIFA Predoctoral Fellowship grant(2018-67011-28041).
文摘Background:Intestinal microbiota plays a key role in nutrient digestion and utilization with a profound impact on feed efficiency of livestock animals.However,the intestinal microbes that are critically involved in feed efficiency remain elusive.Methods:To identify intestinal bacteria associated with residual feed intake(RFI)in chickens,male Cobb broiler chicks were individually housed from day 14 to day 35.Individual RFI values were calculated for 56 chickens.Luminal contents were collected from the ileum,cecum,and cloaca of each animal on day 35.Bacterial DNA was isolated and subjected to 16S rRNA gene sequencing.Intestinal microbiota was classified to the feature level using Deblur and QIIME 2.High and low RFI groups were formed by selecting 15 and 17 chickens with the most extreme RFI values for subsequent LEfSe comparison of the difference in the microbiota.Spearman correlation analysis was further performed to identify correlations between the intestinal microbiota composition and RFI.Results:No significant difference in evenness,richness,and overall diversity of the microbiota in the ileum,cecum,or cloaca was observed between high and low RFI chickens.However,LEfSe analysis revealed a number of bacterial features being differentially enriched in either high or low RFI chickens.Spearman correlation analysis further identified many differentially enriched bacterial features to be significantly correlated with RFI(P<0.05).Importantly,not all short-chain fatty acid(SCFA)producers showed a positive association with RFI.While two novel members of Oscillibacter and Butyricicoccus were more abundant in low-RFI,high-efficiency chickens,several other SCFA producers such as Subdoligranulum variabile and two related Peptostreptococcaceae members were negatively associated with feed efficiency.Moreover,a few closely-related Lachnospiraceae family members showed a positive correlation with feed efficiency,while others of the same family displayed an opposite relationship.Conclusions:Our results highlight the complexity of the intestinal microbiota and a need to differentiate the bacteria to the species,subspecies,and even strain levels in order to reveal their true association with feed efficiency.Identification of RFI-associated bacteria provides important leads to manipulate the intestinal microbiota for improving production efficiency,profitability,and sustainability of poultry production.
基金supported by the USDA National Institute of Food and Agriculture (grant no. 2018–68003-27462 and 2018–67011-28041)the Ralph F. and Leila W. Boulware Endowment FundOklahoma Agricultural Experiment Station Project H-3112。
文摘Background:Intestinal microbiota is critical for maintaining animal health and homeostasis.However,involvement of the fungal community,also known as the mycobiota,in animal health and disease is poorly understood.This study was aimed to examine the association between the intestinal mycobiota and the severity of necrotic enteritis(NE),an economically significant poultry disease.Methods:A total of 90 day-of-hatch Cobb broilers were infected with Eimeria maxima on d 10,followed by an oral challenge with C.perfringens on d 14 to induce NE,while another 10 broilers were served as mock-infected controls.On d 17,the lesions in the jejunum were scored,and the ileal digesta were subjected to DNA isolation and real-time PCR quantification of total bacterial and fungi populations.Internal transcribed spacer 2(ITS2)amplicon sequencing was also performed to profile the ileal mycobiota composition.Changes in the ileal mycobiota in response to NE were investigated.Spearman correlation analysis was further conducted to identify the correlations between relative abundances of individual ileal fungi and the severity of NE.Results:While the total bacterial population in the ileum was increased by 2-to 3-fold in NE chickens,the total fungal population was progressively declined in more exacerbated NE,with the most severely infected chickens showing a nearly 50-fold reduction relative to mock-infected controls.Richness of the ileal mycobiota also tended to reduce in chickens with NE(P=0.06).Compositionally,among 30 most abundant fungal amplicon sequence variants(ASVs),11 were diminished and 7 were enriched(P<0.05),while 12 remained largely unchanged in NEafflicted chickens(P>0.05).Multiple Wallemia and Aspergillus species were markedly diminished in NE(P<0.05)and also showed a significant negative correlation with NE severity(P<0.05).Conclusions:Dysbiosis of the ileal mycobiota is induced evidently by NE and the extent of the dysbiosis is positively correlated with disease severity.These findings suggest a possible role of the intestinal mycobiota in NE pathogenesis and highlight the mycobiota as a new potential target for NE mitigation in poultry.
