Australian House & Garden 165Illustration by Antonia Pesenti.
F
ood allergies, inflammatory bowel
disease and obesity are different
health problems but they do have
some things in common. There’s a
growing suspicion that changes to the
bacteria living in our gut could be
helping these diseases to thrive, and
that our lifestyle and overuse of
antibiotics may be part of the reason.
Humans have evolved to live with the
trillions of microbes inhabiting the gut.
When things go smoothly, it’s a
harmonious relationship. We provide
the microbes with food and a snug place
to live; they return the favour by helping
to keep our immune system and
digestive tract healthy.
There’s evidence connecting the rise
in some chronic ailments, including
allergies and obesity, to shifts in the
population of these bugs, says Dr Simon
Keely, senior lecturer in immunology
and microbiology at the University of
Newcastle. “When you alter the body’s
microbiota, you give other microbes a
chance to thrive,” he explains.
Research suggests that similar
disruptions to gut microbes may lay the
foundations for other diseases. Studies
have found that subjects with food
allergies, for instance, have a different
mix of gut microbes to those found in
healthy people. They are missing
certain bacteria that may be protective,
says Dr Keely. “A US study looking atantibiotic use in children under three
found that those who’d had three or
more courses of antibiotics were twice
as likely as other children to develop a
food allergy.”
Diets low in fibre and high in
processed food are other suspects. It’s
thought that lifestyle factors such as
diet and possibly stress, along with
antibiotics, may drive changes in gut
microbes that set some people up for
inflammatory bowel disease. “We think
that in people whose gut microbiome is
altered, a trigger event such as infection
may lead to chronic inflammation,”
says Dr Keely.
It’s not clear yet, he adds, whether
changes in gut bacteria are a cause or a
result of health problems. “People with
chronic diseases are often more stressed
or less active because of their disease. It
may be this that’s causing a change in
gut microbes.”
Other research has also linked autism,
depression and some other diseases to
changes in gut microbes.
How can we maintain a healthy
balance of gut bacteria? Until we know
more, Dr Keely advises caution when it
comes to using antibiotics. “Overusing
them is probably doing more harm
than good,” he says. “I also think that
a healthier diet and moving away
from a sedentary lifestyle are very
important factors.” #FARE WELL
How o en do you eat
lentils, beans or cooled
cooked potato? Like
wholegrains and firm
bananas, these foods
are sources of resistant
starch, a type of fibre
linked to better gut
health and a reduced
risk of bowel cancer,
according to the CSIRO.
Resistant starch acts
as food for friendly gut
microbes, which then
produce a substance
called butyrate that
helps keep the bowel
lining healthy. More
potato salad or chilli
beans, anyone?GUT REACTION
Evidence is mounting that gut microbes
play an important role in maintaining
good health, writes Paula Goodyer.
H&G HEALTH