title: Dietary L-glutamine supplementation modulates microbial community and activates innate immunity in the mouse intestine.
abstract: 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-κB), 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-κB 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-κB 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-κB, MAPK and PI3K-Akt signaling pathways.
authors.affiliation: Key Laboratory of Agro-ecological Processes in Subtropical Region, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, 410125, Hunan, China, renwenkai19@126.com.
authors.forename: Wenkai
authors.initials: W
authors.lastname: Ren
authors.forename: Jielin
authors.initials: J
authors.lastname: Duan
authors.forename: Jie
authors.initials: J
authors.lastname: Yin
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Zhong
authors.initials: Z
authors.lastname: Cao
authors.forename: Xia
authors.initials: X
authors.lastname: Xiong
authors.forename: Shuai
authors.initials: S
authors.lastname: Chen
authors.forename: Tiejun
authors.initials: T
authors.lastname: Li
authors.forename: Yulong
authors.initials: Y
authors.lastname: Yin
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Hou
authors.forename: Guoyao
authors.initials: G
authors.lastname: Wu
mesh_terms: D000818:Animals; D041963:Bacteroidetes / Q000145:classification / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification; D003106:Colon / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D019587:Dietary Supplements; D005260:Female; D005973:Glutamine / Q000008:administration & dosage*; D020397:Goblet Cells / Q000276:immunology / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000145:classification / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification; D007082:Ileum / Q000166:cytology / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D007113:Immunity, Innate; D007155:Immunologic Factors / Q000008:administration & dosage*; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology / Q000378:metabolism / Q000382:microbiology*; D007421:Intestine, Small / Q000166:cytology / Q000276:immunology / Q000378:metabolism / Q000382:microbiology*; D007583:Jejunum / Q000166:cytology / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D008813:Mice, Inbred ICR; D058889:Molecular Typing; D019879:Paneth Cells / Q000276:immunology / Q000378:metabolism; D011897:Random Allocation; D015398:Signal Transduction; D013047:Specific Pathogen-Free Organisms; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism
chemical_list: D016207:Cytokines; D007155:Immunologic Factors; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D005973:Glutamine