| With the increase of standardization and intensification of poultry farming,the density of breeding environment has increased,and the stimulation of environmental pathogenic factors on the gut microbiota and immune system of poultry has an increasing impact on the aquaculture industry.Fecal microbiota transplantation(FMT)has been widely used in recent years in treating various human diseases,and has shown significant results in research on the growth,development,and immune regulation of poultry and ruminant animals.However,due to the presence of harmful bacteria during the transplantation process,there is a certain risk of FMT.And fecal virome transplantation(FVT)may avoid the occurrence of this problem.Therefore,in this study,cecum contents of 28-day-old AA broilers were transplanted to AA young broilers through FMT and FVT,to explore the effects of FMT and FVT on the development of the immune system of broilers,and to explore the effects of FMT and FVT in improving inflammatory damage and ileal microbiota disorder caused by lipopolysaccharide(LPS)of Escherichia coli in broilers.Exp.1 The effect of fecal microbiota transplantation and fecal virome transplantation on the immune function of chickensTo determine the effects of FMT and FVT on the immune function of broilers,1681-day-old AA white feather broiler chickens were selected half male and female and randomly assigned to three groups,56 broilers per group: the control group(CON group)was given sterile PBS solution via gavage;FMT group;FVT group.On the 5th day of age(D5),gavage treatment was administered at a rate of 300 μL per chicken per day for 6consecutive days.The donors for FMT and FVT were 28-day-old healthy AA broilers.At the age of 7 days(D7),11 days(D11),and 15 days(D15),samples were collected from 24 chickens of similar weight,with 8 broilers in each group,half male and femal.The immune organ indexes were recorded at D7,D11,and D15,and the relative expression of immuneand barrier-related cytokines m RNA in the ileum mucosa and s Ig A in the ileum at D11 and D15 were detected.The results showed that: 1)FMT and FVT significantly reduced the bursa index of AA broilers at D7(P < 0.001),and FMT significantly increased the spleen index at D11(P < 0.01).FMT and FVT did not significantly affect the thymus index,spleen index and bursa index at D15(P > 0.05);2)FMT significantly downregulated the m RNA expression of ZO-1 in ileal mucosa at D11(P < 0.05),while FMT and FVT significantly upregulated the m RNA expression of ZO-1 in ileal mucosa at D15(P < 0.001);3)FVT significantly upregulated the expression of MUC-1 m RNA in ileal mucosa at D11(P < 0.05);4)FMT and FVT significantly upregulated the m RNA expression of IL-6 in ileal mucosa at D15(P < 0.05),while fecal toxin transplantation significantly upregulated the TNF-α m RNA expression level in ileal mucosa at D15(P < 0.01),FVT significantly increased the expression of IL-10 m RNA in ileal mucosa at D15(P < 0.05);5)FMT and FVT did not significantly affect the relative expression of secretory immunoglobulin A(s Ig A)in ileum at D11 and D15(P > 0.05).The results of this experiment indicated that both FMT and FVT could improve the development and barrier function maintenance of the ileal mucosal immune system in broiler chickens,and FVT had less stimulation on the body compared to FMT,which could better exert immune activation effects.Exp.2 The therapeutic effect and mechanism of fecal microbiota transplantation and fecal virome transplantation on LPS-induced inflammation and ileal microbiota disorder in broilersTo determine the effects and mechanisms of FMT and FVT on LPS-induced ileal microbiota disorder and inflammatory damage in broilers,224 1-day-old AA broiler chickens were selected half male and female and randomly assigned to 4 groups,56 broilers per group:a negative control group(CON group),with sterile physiological saline injection and sterile PBS solution gavage;the positive control group(LPS group),who received LPS injection and sterile PBS solution gavage;LPS + FMT group,with LPS injection and FMT;LPS +FVT group,with LPS injection and FVT.Physiological saline or LPS injection were conducted on the 5th day of age(D5)for 3 consecutive days.The intraperitoneal injection volume of LPS was 0.5 mg/kg on the first day,0.5 mg/kg on the second day,and 1.25 mg/kg on the third day.The volume of physiological saline and LPS injection liquid was equal.On the 8th day of age(D8),gavage treatment was administered at a rate of 300 μL per chicken per day for 3 consecutive days.The donors for FMT and FVT were 28-day-old healthy AA broilers.At the age of 11 days(D11)and 15 days(D15),samples were collected from 32 chickens of similar weight,with 8 broilers in each group,half male and femal.At the age of11 days(D11),and 15 days(D15),samples were collected from 24 chickens of similar weight,with 8 broilers in each group.The immune organ indexes were recorded at D11,and D15,and the relative expression of immune-and barrier-related cytokines m RNA in the ileum mucosa and s Ig A in the ileum at D11 and D15 were detected.The morphology of the ileum was measured at D11 and D15.The content of the ileum at D11 was detected by metagenomic sequencing.The results showed that: 1)LPS injection had no significant effect on thymus index,spleen index and bursa index at D11 and D15(P > 0.05);2)LPS injection had no significant effect on the morphology of ileum tissue at D11 and D15(P > 0.05);3)LPS injection significantly upregulated IFN-γ m RNA expression levels(P < 0.05),significantly increased IL-8 m RNA expression levels(P < 0.001)in ileal mucosa at D11,while FMT and FVT significantly reduced IL-8 and IFN-γ m RNA expression level,FVT significantly increased the m RNA expression of IL-10 in ileal mucosa at D11(P < 0.001);4)LPS injection significantly upregulated the m RNA expression of ZO-1 in ileal mucosa at D11(P < 0.01),while FMT and FVT significantly reduced the m RNA expression of ZO-1;5)LPS injection significantly reduced the relative expression of s Ig A in ileum at D11(P <0.05),LPS treatment significantly increased the ratio of positive area to tissue area of s Ig A in ileum at D15(P < 0.01),and fecal toxin transplantation significantly reduced the ratio of positive area to tissue area of s Ig A in ileum at D15;6)metagenomic results at D11 showed that LPS injection significantly increased the relative abundance of virulence factor Rab2 interacting conserved protein A(VFDB 2023)related genes in broiler ileum contents(P <0.05),and FVT could significantly reduce the relative abundance of them.LPS injection significantly downregulated the Carbapenem biosynthesis pathway(P < 0.05),Polyketide sugar unit biosynthesis pathway(P < 0.05),and Biosynthesis of antibiotics pathway(P <0.05)in the ileal contents.FVT significantly upregulated the Biosynthesis of antibiotics pathway.The results of this experiment indicated that LPS injection had a certain impact on the ileal microbiota and immune function of broilers,and different immune responses may occur with different sample collecting time points.Both FMT and FVT could promote the recovery of inflammation caused by LPS,and FVT could reduce the risk of transmission of pathogenic genes compared to FMT. |
PDF Full Text Request