Learn about the hygiene hypothesis and understand how exposure to certain germs help develop a child's immunity

Learn about the hygiene hypothesis and understand how exposure to certain germs help develop a child's immunity

Research suggests that exposure to germs early in life helps a child develop a healthy immune system.
Science in Seconds (www.scienceinseconds.com) (A Britannica Publishing Partner)
  • © American Chemical Society (A Britannica Publishing Partner)
    Learn about the chemistry of marijuana and how its potency and safety is determined.
  • Time-lapse video, by Dutch photographer Frans Hofmeester, of his daughter from birth to age 12.
  • © University of Melbourne, Victoria, Australia (A Britannica Publishing Partner)
    See a 3-D simulation of the motion of the human rhinovirus, the virus that causes the common cold. The simulation was produced with the aid of the IBM Blue Gene/Q supercomputer.
  • © American Chemical Society (A Britannica Publishing Partner)
    Learn what allergies are and what causes them.
  • Encyclopædia Britannica, Inc.
    Learn about the human immune response phagocytosis by watching time-lapse photography of a leukocyte, or white blood cell (globular structure), consuming bacteria.
  • © American Chemical Society (A Britannica Publishing Partner)
    Debunking the claims of hypoallergenic products.
  • © American Chemical Society (A Britannica Publishing Partner)
    Researchers developed an experimental immune system treatment, returning the power of movement to paralyzed mice.

News •

Cancer uses antioxidants to disarm the immune system, scientists discover • Nov. 10, 2026, 6:58 AM ET (Science Daily)
Could a flu shot help fight skin cancer? • Nov. 9, 2026, 5:30 PM ET (Medical Xpress)
Scientists solve a 30-year mystery behind inflammatory bowel disease • Oct. 26, 2026, 7:58 PM ET (Science Daily)

Transcript

[Music in]

TORAH KACHUR: The universal loathing of children for bathing might just be evolution at work. Parents, it's time to put down the antibiotic lens cleaner, the antiviral yoga pants, and the ridiculous toilet bowl cleaner. Oh, okay, not that one.

It's time to build a sandbox, go camping, and let children be--well--children. The hygiene hypothesis says that exposure to germs early in life is critical to develop a healthy immune system. Swimming in scum-filled ponds or playing in the barn exposes a child's immune system to hepatitis A, Helicobacter pylori, and other nasty-sounding pathogens, but the kids magically don't die. Instead, the exposure to low levels of disease-causing germs has been linked to reduced rates of pesky conditions like asthma and other autoimmune disorders. These are conditions when your body's immune system attacks itself by accident, like irritable bowel, multiple sclerosis, and type I diabetes, diseases almost exclusively found in the developed world. The immunoprotective effect of just dirt is accomplished almost exclusively in childhood, for the immune system is learning all sorts of things about what is good and bad from the environment.

It's in the sandbox where children learn how to share, pee standing up, and activate their regulatory T cells. Regulatory T cells are a type of immune cell that is responsible for controlling the degree of the immune response and tempering attacks on your own body.

Researchers have found that when children are exposed to low levels of feces and contaminated water, this causes the regulatory T cells to learn what is environment and what is self.

So, stop being so ridiculously hygienic when it comes to your kids. We evolved in the outdoors and have learned to benefit from it. If your kid gets the sniffles from it, it's still better than an irritable bowel.

[Music out]

Last Modification: