The role ofin uteroendotoxin exposure in the development of inflammatory bowel disease in mice

Problem Although early environmental influences are thought to influence the development of inflammatory bowel disease (IBD), little is known about the role of thein uteroenvironment on subsequent IBD risk. We hypothesized that prenatal exposure to bacterial lipopolysaccharide (LPS) could modify the subsequent development of dextran sulfate sodium (DSS)-induced ulcerative colitis in adulthood by influencing the associated cellular and immune response. Method of Study To test this hypothesis, we exposed developing micein uteroto LPS or saline (PBS) at E17.5, and then induced colitis at 5 weeks. We then assessed colitis severity and effects on the microbiome. In order to define the developmental impact of any potential LPS effect, we also exposed 1-week-old mice to either LPS or saline before inducing colitis at 5 weeks. Results Mice that had been exposed to LPS but not salinein uterowere protected from subsequent colitis development, and their intestinal barrier integrity and tight junction expression distribution were similar to that of control mice that were not exposed to DSS. By contrast, mice exposed to either LPS or saline at day 7 of life all developed severe colitis upon subsequent DSS exposure. Conclusion These results identify an informative time window during fetal development during which exposure to an otherwise pro-inflammatory agent like LPS protects against an inflammatory disease in adulthood.