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草业学报 ›› 2024, Vol. 33 ›› Issue (12): 188-200.DOI: 10.11686/cyxb2024024

• 研究论文 • 上一篇    

饲喂胆汁酸对亚急性瘤胃酸中毒山羊回肠黏膜形态、菌群组成和IFN-γ mRNA相对表达量的影响

陈悦(), 宋品, 侯曼曼, 杨笑然, 刘丽萍, 倪迎冬()   

  1. 南京农业大学动物医学院,农业农村部动物生理生化重点实验室,江苏 南京 210095
  • 收稿日期:2024-01-16 修回日期:2024-03-11 出版日期:2024-12-20 发布日期:2024-10-09
  • 通讯作者: 倪迎冬
  • 作者简介:E-mail: niyingdong@njau.edu.cn
    陈悦(1998-),女,安徽安庆人,在读硕士。E-mail: Superlucky9812@163.com
  • 基金资助:
    国家自然科学基金(32172810)

Effects of dietary supplementation with bile acid on ileal epithelial morphology, microflora composition, and relative transcript levels of IFN-γ in the ileal mucosa of goats with subacute ruminal acidosis

Yue CHEN(), Pin SONG, Man-man HOU, Xiao-ran YANG, Li-ping LIU, Ying-dong NI()   

  1. College of Veterinary Medicine,Nanjing Agricultural University,Key Laboratory of Animal Physiology and Biochemistry,Ministry of Agriculture and Rural Areas,Nanjing 210095,China
  • Received:2024-01-16 Revised:2024-03-11 Online:2024-12-20 Published:2024-10-09
  • Contact: Ying-dong NI

摘要:

为探讨饲喂胆汁酸对高精料日粮诱导的亚急性瘤胃酸中毒(SARA)山羊回肠黏膜结构、菌群组成和抗炎因子mRNA相对表达量的影响,本试验选取15头3月龄雄性山羊(18.19±2.83 kg),手术安置永久性瘤胃瘘管,2周恢复期后随机分为3组:对照组(CON),亚急性瘤胃酸中毒组(SARA),亚急性瘤胃酸中毒加胆汁酸组(SARA+BA),每组5只羊。CON组每天饲喂精粗比为3∶7的日粮,SARA组和SARA+BA组饲喂精粗比为7∶3的日粮, SARA+BA组每天通过瘤胃瘘管灌注饲喂3 g胆汁酸,饲喂期为6周。试验结束后采集回肠上皮组织观察形态结构、上皮内杯状细胞和潘氏细胞数量,并检测黏膜中干扰素γ(IFN-γ)及受体的mRNA相对表达量和回肠内容物中菌群组成。结果表明:与CON组相比,SARA组山羊回肠上皮刷状缘呈锯齿状不规则形态,表明有一定程度的损伤,但绒毛和隐窝处杯状细胞和潘氏细胞数量无显著差异(P>0.05),回肠黏膜中IFN-γ和受体IfnGR1 mRNA相对表达量有下降的趋势(0.05<P<0.1),回肠内容物中微生物多样性指数(Ace、Shannon)均显著降低(P<0.05),门水平上厚壁菌门的相对丰度显著增加(P<0.05),属水平有益菌Unclassified_f_LachnospiraceaeRuminococcusChristensenellaceae_R-7_group相对丰度显著减少(P<0.05),但有害菌Erysipelotrichaceae_UCG-006Clostridium_sensu_stricto_1相对丰度显著增加(P<0.05)。与SARA组相比,SARA+BA组山羊回肠上皮刷状缘光滑、结构完整,绒毛高度显著升高(P<0.05),绒毛和隐窝处杯状细胞数量无显著差异(P>0.05),但潘氏细胞显著增多(P<0.05);黏膜中IFN-γ mRNA相对表达量有上调的趋势(0.05<P<0.1),其受体IfnGR1 mRNA相对表达量显著上调(P<0.05);回肠内容物中菌群多样性指数(Ace)显著升高(P<0.05),门水平上厚壁菌门的相对丰度显著降低(P<0.05),属水平上有益菌Unclassified_f_LachnospiraceaeRuminococcusChristensenellaceae_R-7_group相对丰度显著升高(P<0.05),而有害菌Erysipelotrichaceae_UCG-006Clostridium_sensu_stricto_1相对丰度显著降低(P<0.05)。综上,饲喂胆汁酸可改善SARA山羊的回肠形态结构,缓解回肠内菌群紊乱,通过上调黏膜中抗炎因子IFN-γIfnGR1 mRNA相对表达量,从而缓解SARA山羊回肠黏膜的损伤。

关键词: 胆汁酸, 亚急性瘤胃酸中毒, 回肠黏膜, 菌群组成, 山羊

Abstract:

The aim of this study was to investigate the effect of dietary supplementation with bile acid on intestinal mucosal structure, intestinal microflora composition, and the relative transcript levels of IFN-γ (encoding interferon γand IfnGR1 (encoding the IRN-γ receptor)in the ileal mucosa of goats with subacute ruminal acidosis (SARA) induced by a high-concentrate diet. Fifteen 3-month-old male goats (mean weight, 18.19±2.83 kg) were selected and implanted with permanent rumen fistulas by surgery. After a 2-week recovery period, the goats were randomly divided into three groups: a control group (CON), a subacute ruminal acidosis group (SARA), and a SARA plus bile acids treatment group (SARA+BA), with five goats in each group. Goats in the CON group were fed with a low-concentrate diet (concentrate∶forage=3∶7), those in the SARA and SARA+BA groups were fed with a high-concentrate diet (concentrate∶forage=7∶3), and those in the SARA+BA group were fed with an additional 3 g of bile acid through the rumen fistula every day for 6 weeks. At the end of the experiment, the goats were slaughtered and the ileal epithelial tissues were sampled to analyze their morphology, the characteristics of goblet cells and paneth cells, and the transcript levels of IFN-γ and IfnGR1 in the mucosa. In addition, the ileal digesta were collected to analyze the composition of the microbial community. The results showed that, compared with the CON group, the SARA group showed an irregularly shaped brush border of the ileal epithelium, indicative of a degree of injury, but no significant difference in the number of cup cells and paneth cells in the villi and crypt (P>0.05). Compared with the CON group, in the SARA group, the transcript levels of IFN-γ and IfnGR1 in the ileum mucosa were decreased (0.05<P<0.1), the diversity of the microbial community (Ace and Shannon’s indexes) in the ileum contents was decreased (P<0.05), and the relative abundance of the phylum Firmicutes in the microbial community in the ileum was significantly increased (P<0.05). Compared with the CON group, the SARA group showed significantly lower relative abundance of Unclassified_f_LachnospiraceaeRuminococcus and Christensenellaceae_R-7_groupP<0.05) and significantly higher relative abundance of Erysipelotrichaceae_UCG-006 and Clostridium_sensu_stricto_1P<0.05) in the microbial community. Compared with the SARA group, the SARA+BA group had a smoother brush border of the ileal epithelium, the epithelial structure was complete, the villi height was significantly increased (P<0.05), and the number of paneth cells was significantly increased (P<0.05), but the number of cup cells in the villi and crypt was not significantly different (P>0.05). Also, compared with the SARA group, the SARA+BA group showed increased transcript levels of IFN-γ in the mucosa (0.05<P<0.1), increased transcript levels of IfnGR1P<0.05), significantly increased bacterial diversity (Ace index) in the ileum microbial community (P<0.05), and a lower relative abundance of the phylum Firmicutes (P<0.05). At the genus level, the beneficial bacteria Unclassified_f_LachnospiraceaeRuminococcus and Christensenellaceae_R-7_group were more abundant in the SARA+BA group than in the SARA group (P<0.05), and the harmful bacteria Erysipelotrichaceae_UCG-006 and Clostridium_sensu_stricto_1 were significantly less abundant (P<0.05). In conclusion, feeding bile acid to goats with subacute ruminal acidosis improved the morphology and structure of the ileum of SARA goats, alleviated the disturbance of the microflora in the ileum, and alleviated damage to the ileum mucosa of SARA goats by up-regulating the relative mRNA expression levels of anti-inflammatory factor IFN-γ and receptor IfnGR1 in the mucosa.

Key words: bile acid, subacute ruminal acidosis, ileal mucosa, microflora composition, goat