Bacteria get a lot of bad press when they make our lives harder, but all the good that they do for us mostly goes unnoticed. That's starting to change thanks to groundbreaking research like the Human Microbiome Project, which is trying to do for the microorganisms found living alongside humans what the Human Genome Project did for our DNA. And as we learn more, we're starting to realize that a lot of seemingly unrelated health issues in fact governed by the tiny unicellular creatures that we're exposed to throughout our lives.
A recent piece of research by Canadian scientists has found an interesting link between a baby's exposure to certain 'friendly' bacteria and the risk of developing asthma and allergies later in life.
The looked at 319 children:
The team, at the University of British Columbia and the Children's Hospital in Vancouver, compared the microbiome at three months and at one year with asthma risk at the age of three.
Children lacking four types of bacteria - Faecalibacterium, Lachnospira, Veillonella, and Rothia (Flvr) - at three months were at high risk of developing asthma at the age of three, based on wheeze and skin allergy tests.
The same effect was not noticed in the microbiome of one-year-olds, suggesting that the first few months of life are crucial.
To test this hypothesis, the scientists exposed germ-free mice to these bacteria and say a reduction in inflammation (a sign of asthma) in the airways of the mice pups.
With further research and testing, if this finding is correct and there are no negative side effects, it might one day become possible to supplement young children with these 'good bacteria' to prevent diseases like asthma.
One explanation for the rise in asthma and allergies is the "hygiene hypothesis", which suggests that children are no longer exposed to enough microbes to calibrate the immune system to tell the difference between friend and foe.
Giving birth by Caesarean section and not breast-feeding both limit the bacteria that are passed to a newborn. Antibiotics taken by a pregnant woman or newborn child can also change the microbiome. (source)