Enterococcus faecalis from healthy infants modulates inflammation through MAPK signaling pathways

• Published in: PloS one Vol. 9; no. 5; p. e97523
• Main Authors: Wang, Shugui, Hibberd, Martin Lloyd, Pettersson, Sven, Lee, Yuan Kun
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 15.05.2014; Public Library of Science (PLoS)
• Subjects: Allergies; Animals; Babies; Bacteria; Biology and life sciences; Births; Caco-2 Cells; Cancer; Colonization; Comparative analysis; Culture Media, Conditioned - chemistry; Digestive system; Digestive tract; Enterococcus; Enterococcus faecalis; Enterococcus faecalis - genetics; Enterococcus faecalis - metabolism; Gastrointestinal system; Gastrointestinal tract; HCT116 Cells; HT29 Cells; Humans; Hypersensitivity; Immune system; Immunity; Indonesia; Infant; Infant, Newborn; Infants; Infections; Inflammation; Inflammation - metabolism; Inflammation - microbiology; Inflammatory bowel disease; Interleukin 8; Interleukin-1beta - metabolism; Interleukin-8 - metabolism; Intestines - metabolism; Intestines - microbiology; JNK protein; Kinases; Lactobacilli; Lactobacillus; Lactobacillus - genetics; Lactobacillus - metabolism; Male; MAP kinase; MAP Kinase Signaling System; Medicin och hälsovetenskap; Medicine and Health Sciences; Mice; Mice, Inbred C57BL; Microbiota; Microbiota (Symbiotic organisms); Neonates; Neutrophils; Newborn infants; Phosphorylation; Phylogenetics; Phylogeny; Polymerase Chain Reaction; Probiotics; Proteins; Research and Analysis Methods; Ribosomal DNA; RNA, Ribosomal, 16S - genetics; Salmonella typhimurium - metabolism; Secretions; Signal transduction; Signaling; Studies; TNF inhibitors; Tumor Necrosis Factor-alpha - metabolism; Tumor necrosis factor-TNF; Indonesia; Singapore
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0097523

Colonizing commensal bacteria after birth are required for the proper development of the gastrointestinal tract. It is believed that bacterial colonization pattern in neonatal gut affects gut barrier function and immune system maturation. Studies on the development of faecal microbiota in infants showed that the neonatal gut was first colonized with enterococci followed by other microbiota such as Bifidobacterium. Other studies showed that babies who developed allergy were less often colonized with Enterococcus during the first month of life as compared to healthy infants. Many studies have been conducted to elucidate how bifidobacteria or lactobacilli, some of which are considered probiotic, regulate infant gut immunity. However, fewer studies have been focused on enterococi. In our study, we demonstrate that E. faecalis, isolated from healthy newborns, suppress inflammatory responses activated in vivo and in vitro. We found E. faecalis attenuates proinflammatory cytokine secretions, especially IL-8, through JNK and p38 signaling pathways. This finding shed light on how the first colonizer, E.faecalis, regulates inflammatory responses in the host.