Skip to main content
NIH Intramural Research Program, Our Research Changes Lives

Navigation controls

  • Search
  • Menu

Social follow links

  • Podcast
  • Instagram
  • Twitter
  • YouTube
  • LinkedIn

Main navigation

  • About Us
    • What Is the IRP?
    • History
    • Honors
      • Nobel Prize
      • Lasker Award
      • Breakthrough Prize
      • Shaw Prize
      • Presidential Early Career Award for Scientists and Engineers (PECASE)
      • Presidential Medal of Freedom
      • National Medal of Science
      • Searle Scholars
      • The National Academy of Sciences
      • The National Academy of Medicine
      • The National Academy of Engineering
      • The American Academy of Arts and Sciences
      • National Medal of Technology & Innovation
      • Samuel J. Heyman Service to America Medals
      • Crafoord Prize
      • Fellows of the Royal Society
      • Canada Gairdner Awards
    • Organization & Leadership
    • Our Programs
      • NCI
      • NEI
      • NHGRI
      • NHLBI
      • NIA
      • NIAAA
      • NIAID
      • NIAMS
      • NIBIB
      • NICHD
      • NIDA
      • NIDCD
      • NIDCR
      • NIDDK
      • NIEHS
      • NIMH
      • NIMHD
      • NINDS
      • NINR
      • NLM
      • CC
      • NCATS
      • NCCIH
    • Research Campus Locations
    • Contact Information
  • Our Research
    • Scientific Focus Areas
      • Biomedical Engineering & Biophysics
      • Cancer Biology
      • Cell Biology
      • Chemical Biology
      • Chromosome Biology
      • Clinical Research
      • Computational Biology
      • Developmental Biology
      • Epidemiology
      • Genetics & Genomics
      • Health Disparities
      • Immunology
      • Microbiology & Infectious Diseases
      • Molecular Biology & Biochemistry
      • Molecular Pharmacology
      • Neuroscience
      • RNA Biology
      • Social & Behavioral Sciences
      • Stem Cell Biology
      • Structural Biology
      • Systems Biology
      • Virology
    • Principal Investigators
      • View by Investigator Name
      • View by Scientific Focus Area
    • Accomplishments
      • View All Accomplishments by Date
      • View All Health Topics
      • The Body
      • Health & Wellness
      • Conditions & Diseases
      • Procedures
    • Accelerating Science
      • Investing in Cutting-Edge Animal Models
      • Creating Cell-Based Therapies
      • Advancing Computational and Structural Biology
      • Combating Drug Resistance
      • Developing Novel Imaging Techniques
      • Charting the Pathways of Inflammation
      • Zooming in on the Microbiome
      • Uncovering New Opportunities for Natural Products
      • Stimulating Neuroscience Research
      • Pursuing Precision Medicine
      • Unlocking the Potential of RNA Biology and Therapeutics
      • Producing Novel Vaccines
    • Research in Action
      • View All Stories
      • Battling Blood-Sucking Bugs
      • Unexpected Leads to Curb Addiction
      • Shaping Therapies for Sickle Cell Disease
      • The Mind’s Map Maker
    • Trans-IRP Research Resources
      • Supercomputing
    • IRP Review Process
    • Commercializing Inventions
  • NIH Clinical Center
    • Clinical Center Facilities
    • Clinical Faculty
    • Advancing Translational Science
    • Clinical Trials
      • Get Involved with Clinical Research
      • Physician Resources
  • News & Events
    • In the News
    • I am Intramural Blog
    • Speaking of Science Podcast
    • SciBites Video Shorts
    • The NIH Catalyst Newsletter
    • Events
  • Careers
    • Faculty-Level Scientific Careers
    • Trans-NIH Scientific Recruitments
      • Stadtman Tenure-Track Investigators
        • Science, the Stadtman Way
      • Lasker Clinical Research Scholars
      • Independent Research Scholar
    • Scientific & Clinical Careers
    • Administrative Careers
  • Research Training
    • Program Information
    • Training Opportunities
    • NIH Work/Life Resources
The NIH Catalyst: A Publication About NIH Intramural Research

National Institutes of Health • Office of the Director | Volume 19 Issue 4 • July–August 2011

Germ-Free Mice

New Facility for Microbe Study

By Julie Wu, NIAID

Some 100 trillion beneficial microorganisms—bacteria, fungi, and viruses—populate your body inside and out. Many species keep us healthy by helping with digestion, producing nutrients, and strengthening the immune system. But what would happen if we didn’t have this assortment of beneficial, or commensal, microbiota living within us? To find out, NIH scientists are studying germ-free mice that have not been naturally colonized by microorganisms.

NIAID is home to one of the few facilities in the United States that houses so-called gnotobiotic mice. These mice are born in germ-free conditions, and investigators control the microbiota by inoculating the animals with specific microorganisms. The word “gnotobiotic” comes from the Greek words gnostos, for known, and bios, for life.

When the field of commensal research exploded in the mid-2000s, many NIH investigators already were conducting research on microbiota. “But there were very few intramural resources available for studying commensals [at NIH],” said NIAID senior investigator Yasmine Belkaid. “It became obvious we needed a germ-free animal facility to support investigations on campus.”

Photo: NIAID

In NIAID’s gnotobiotic mice facility, technicians handle the germ-free animals with gloves attached to isolators.

Belkaid got her wish soon enough. In July 2008, investigators and staff in NIAID’S Comparative Medicine Branch (CMB), directed by veterinarian Randy Elkins, identified facilities in which to house germ-free mice. They then purchased 12 isolators that contain five cages each; each of the 60 cages is capable of housing five mice. The National Gnotobiotic Rodent Resource Center at the University of North Carolina-Chapel Hill provided training in how to care for, maintain, and conduct research with these germ-free mice.

Research has since spread faster than germs across the NIH through collaborations with NIAID researchers. For example, Belkaid’s group is working on projects with senior investigators Julie Segre at NHGRI and Giorgio Trinchieri at NCI.

Segre, who leads the NIH Human Microbiome Project, studies the role of the skin as a barrier between the body and the environment. Her project with Belkaid involves exploring the relationship between the immune cells and bacteria at the skin barrier.

Trinchieri’s lab aims to understand how gut flora affect the pathogenesis of inflammation and immune colitis (inflammation of the colon or large intestine) and, in mouse models, of colitis-associated cancer. By studying germ-free mice that are deficient in immune- or inflammation-related genes and inoculating them with defined flora, his lab can distinguish between the effects of genes and the role of commensals.

The research is not without its challenges. Gnotobiotic mice are born and raised in sterile conditions. At birth, they are removed from the mother by Caesarean section and live in the isolators with germ-free foster mothers. Investigators must perform all experiments using gloves attached to the isolators so that the animals never come into accidental contact with germs other than those that are deliberately introduced.

The NIAID Gnotobiotic User Committee—made up of veterinarians, investigators, and CMB staff—establishes requirements for working in the facility, maintaining the isolators, and monitoring the status of germ-free and other animals that must be maintained in isolators. The committee also developed a procedure for submitting proposals to use the gnotobiotic mice.

NIAID’s gnotobiotic facility is home to three strains of mice, and more are being generated. Fifteen projects conducted by five NIAID labs have relied on these germ-free mice. Belkaid and Elkins hope to expand the gnotobiotic facility and begin an in-house breeding program. There also are plans to establish a consortium of germ-free mice facilities across the United States, which will enable NIH to share strains and breeding pairs with others.


For more information:

  • NIH Human Microbiome Project
  • Belkaid’s research
  • Segre’s research
  • Trinchieri’s research

This page was last updated on Monday, May 2, 2022

  • Issue Overview
  • Features
    • Germ-Free Mice
    • Robotic Arms
    • An Exit Interview with NIH Library Director Suzanne Grefsheim
    • Dogs Are Shedding... Light on Human Health
    • Major Shared and Multi-Institute Research Resources
  • Departments
    • From the Deputy Director for Intramural Research
    • News You Can Use
    • The Training Page
    • New Methods
    • Research Briefs
    • The SIG Beat
    • Colleagues: Recently Tenured
    • Announcements
    • Laboratory Confessions
  • Issue Contents
  • Download this issue as a PDF

Catalyst menu

  • Current Issue
  • Previous Issues
  • About The NIH Catalyst
  • Contact The NIH Catalyst
  • Share Your Story
  • NIH Abbreviations

Subscribe Today!

Subscribe to The NIH Catalyst Newsletter and receive email updates.

Subscribe

Get IRP Updates

Subscribe

  • Email
  • Print
  • Share Twitter Facebook LinkedIn

Main navigation

  • About Us
    • What Is the IRP?
    • History
    • Honors
    • Organization & Leadership
    • Our Programs
    • Research Campus Locations
    • Contact Information
  • Our Research
    • Scientific Focus Areas
    • Principal Investigators
    • Accomplishments
    • Accelerating Science
    • Research in Action
    • Trans-IRP Research Resources
    • IRP Review Process
    • Commercializing Inventions
  • NIH Clinical Center
    • Clinical Center Facilities
    • Clinical Faculty
    • Advancing Translational Science
    • Clinical Trials
  • News & Events
    • In the News
    • I am Intramural Blog
    • Speaking of Science Podcast
    • SciBites Video Shorts
    • The NIH Catalyst Newsletter
    • Events
  • Careers
    • Faculty-Level Scientific Careers
    • Trans-NIH Scientific Recruitments
    • Scientific & Clinical Careers
    • Administrative Careers
  • Research Training
    • Program Information
    • Training Opportunities
    • NIH Work/Life Resources
  • Department of Health and Human Services
  • National Institutes of Health
  • USA.gov

Footer

  • Home
  • Contact Us
  • IRP Brand Materials
  • HHS Vulnerability Disclosure
  • Web Policies & Notices
  • Site Map
  • Search