Intestinal Microbiota Reduces Genotoxic Endpoints Induced By High-Energy Protons

• DOI: 10.1667/rr13352.1
• Publication Date: 2014-01-07T20:16:59Z
• Authors: Irene Maier; David M. Berry; Robert H. Schiestl
• Keywords: Male; 0301 basic medicine; Extraterrestrial Environment; Endpoint Determination; T-Lymphocytes; 301904 Krebsforschung; 303020 Medizinische Mikrobiologie; Feces; Mice; 03 medical and health sciences; SDG 3 - Good Health and Well-being; Animals; DNA Breaks, Double-Stranded; Linear Energy Transfer; Chromosome Aberrations; Mutagenicity Tests; Microbiota; 3. Good health; Intestines; Oxidative Stress; SDG 3 – Gesundheit und Wohlergehen; 303020 Medical microbiology; Female; Protons; 301904 Cancer research

Ionizing space radiation causes oxidative DNA damage and triggers stress responses, compromised repair mechanisms can lead to increased risk of carcinogenesis. Young adult mice with developed innate adaptive immune systems that harbored either a conventional intestinal microbiota (CM) or an restricted microbial composition (RM) were irradiated total dose 1 Gy delivered by high-energy protons (2.5 GeV/n, LET = 0.2-2 keV/μm) silicon iron ions (850 MeV/n, ≈ 50 keV/μm 150 keV/μm, respectively). Six hours after whole-body irradiation, acute chromosomal lesions observed for RM but not CM mice. High-throughput rRNA gene sequencing mucosal bacteria showed Barnesiella intestinihominis unclassified Bacterodiales significantly more abundant in male than mice, phylotype densities changed In addition, Helicobacter hepaticus Bacteroides stercoris higher Elevated levels persistently phosphorylated γ-H2AX exposed compared nonirradiated they also associated decrease the antioxidant glutathione peripheral blood measured at four weeks irradiation. After exposure, lower phosphorylation increase specific RM-associated phylotypes, indicating down-regulating force on differentially phylotypes versus radiation-sensitive complex CM.