This site is not maintained. Click here for the new website of Richard Dawkins.

Let Them Eat Dirt

Early exposure to microbes shapes the mammalian immune system by subduing inflammatory T cells.

Maybe it’s okay to let your toddler lick the swing set and kiss the dog. A new mouse study suggests early exposure to microbes is essential for normal immune development, supporting the so-called “hygiene hypothesis” which states that lack of such exposure leads to an increased risk of autoimmune diseases. Specifically, the study found that early-life microbe exposure decreases the number of inflammatory immune cells in the lungs and colon, lowering susceptibility to asthma and inflammatory bowel diseases later in life.

The finding, published today (March 21) in Science, may help explain why there has been a rise in autoimmune diseases in sterile, antibiotic-saturated developed countries.

“There have been many clues that environmental factors, particularly microbiota, play a role in disease risk, but there’s very little information about when it’s critical for that exposure to take place,” said Jonathan Braun, chair of pathology and laboratory medicine at the David Geffen School of Medicine at the University of California, Los Angeles, who was not involved in the research. “This is one of the most compelling observations to pin down that time frame.”

The mammalian immune system is dramatically influenced and shaped by exposure to microbes throughout life. Epidemiological evidence suggests that early-life exposure to bacteria may be key in preventing two immune diseases: asthma and ulcerative colitis, a type of inflammatory bowel disease.

Read more



The racism of the respectable

Nick Cohen - The Spectator Comments

To be a racist in Britain, you do not need to cover yourself in tattoos and join a neo-Nazi party. You can wear well-made shirts, open at the neck, appreciate fine wines and vote Left at election time.

The rebranding of circumcision as...

Brendan O'Neill - The Telegraph Comments

The rebranding of circumcision as 'child abuse' echoes the ugly anti-Semitism of medieval Europe

German court rules religious...

AFP - - Comments

Circumcising young boys on religious grounds amounts to grievous bodily harm, a German court ruled

Religious Extremism In Public Schools:...

Katherine Stewart, R. Elisabeth... Comments

Religious Extremism In Public Schools: R. Elisabeth Cornwell & Sean Faircloth interviews author Katherine Stewart

Roman Catholic Church official...

NBC News - MNSBC Comments

A Roman Catholic church official was convicted Friday of child endangerment but acquitted of conspiracy in a groundbreaking clergy-abuse trial

[Update] How Christian fundamentalists...

Katherine Stewart - The Guardian 36 Comments

How Christian fundamentalists plan to teach genocide to schoolchildren



SNAREs at the Synapse

Megan Scudellari - TheScientist Comments

Using tiny lipid discs, scientists resolve contradictory evidence about how many proteins are required for neurotransmitter release.

Next Generation: Sneaking into a Cell

Megan Scudellari - TheScientist 7 Comments

Next Generation: Sneaking into a Cell

A nanoscale device measures electrical signals inside cells without causing damage

Amoeba agriculture

Megan Scudellari - TheScientist 22 Comments

Some slime molds transport and farm the bacteria they eat



Comment RSS Feed

Please sign in or register to comment