Dietary L-glutamine supplementation modulates microbial community and activates innate immunity in the mouse intestine
Dietary L-glutamine supplementation modulates microbial community and activates innate immunity in the mouse intestine
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膳食 L-谷氨酰胺补充剂可调节微生物群落并激活小鼠肠道的先天免疫
DOI：
10.1007/s00726-014-1793-0
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发表时间：
2014-10-01
期刊：
影响因子：
3.5
通讯作者：
Wu, Guoyao
中科院分区：
文献类型：
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作者：
Ren, Wenkai;Duan, Jielin;Wu, Guoyao
本研究旨在确定在小鼠膳食中添加1%l-谷氨酰胺14天对肠道细菌丰度和肠道天然免疫激活的影响。测定小肠内拟杆菌、厚壁菌、乳杆菌、链球菌和双歧杆菌的丰度，空肠、回肠和结肠内潘氏细胞和杯状细胞分泌的Toll样受体（TLR）、促炎细胞因子和抗菌物质的表达;以及（3）在空肠和回肠中激活TLR 4-核因子κ B（NF-κ B）、促分裂原活化蛋白激酶（MAPK）和磷酸肌醇-3-激酶（PI 3 K）/PI 3 K-蛋白激酶B（Akt）信号通路。在空肠中，补充谷氨酰胺降低了厚壁菌门的丰度，同时增加了与NF-κ B和PI 3 K-Akt通路活化相关的抗菌物质的mRNA水平。在回肠中，谷氨酰胺补充诱导厚壁菌门：拟杆菌门比例的转变，有利于拟杆菌门，并增强了TLR 4、促炎细胞因子和参与NF-κ B和JNK信号传导途径的抗菌物质的mRNA水平。这些结果表明，谷氨酰胺对肠道的影响因肠段和隔室而异。总之，小鼠的饮食谷氨酰胺补充有益地改变了肠道细菌群落，并通过NF-κ B、MAPK和PI 3 K-Akt信号通路激活小肠中的先天免疫。
This study was conducted to determine effects of dietary supplementation with 1 % l-glutamine for 14 days on the abundance of intestinal bacteria and the activation of intestinal innate immunity in mice. The measured variables included (1) the abundance of Bacteroidetes, Firmicutes, Lactobacillus, Streptococcus and Bifidobacterium in the lumen of the small intestine; (2) the expression of toll-like receptors (TLRs), pro-inflammatory cytokines, and antibacterial substances secreted by Paneth cells and goblet cells in the jejunum, ileum and colon; and (3) the activation of TLR4-nuclear factor kappa B (NF-kappa B), mitogen-activated protein kinases (MAPK), and phosphoinositide-3-kinases (PI3K)/PI3K-protein kinase B (Akt) signaling pathways in the jejunum and ileum. In the jejunum, glutamine supplementation decreased the abundance of Firmicutes, while increased mRNA levels for antibacterial substances in association with the activation of NF-kappa B and PI3K-Akt pathways. In the ileum, glutamine supplementation induced a shift in the Firmicutes:Bacteroidetes ratio in favor of Bacteroidetes, and enhanced mRNA levels for Tlr4, pro-inflammatory cytokines, and antibacterial substances participating in NF-kappa B and JNK signaling pathways. These results indicate that the effects of glutamine on the intestine vary with its segments and compartments. Collectively, dietary glutamine supplementation of mice beneficially alters intestinal bacterial community and activates the innate immunity in the small intestine through NF-kappa B, MAPK and PI3K-Akt signaling pathways.