March• 2018 | 59READER’S DIGEST
chance of developing type 2 diabetes.
Other species of Prevotella prefer to
eat fibre, and these help the immune
system.
“We’re starting to realise that the
tiny bacteria in our guts play a much
more important role in our health
than we ever imagined,” says Dr Amy
Loughman, psychologist and micro-
biome researcher based at the Food
and Mood Centre at Deakin Univer-
sity in Melbourne. “The community
structure depends on the environment
that’s down there. We’re only just
starting to understand the relevance
of these tiny cells and how they are
connected to everything else. What we
know now is just the tip of the iceberg.”
DNA and the Microbiome
Ancient Greek physician Hippocrates
was the first to allude to the vital role
the gut plays in general health when
he declared, “Let food be thy medi-
cine”. But it’s only in the last ten years
or so that technology has enabled us
to properly study the bacteria that live
inside the human gut.
Using high-throughput sequenc-
ing technology to examine the DNA
of the micro-organisms that inhabit
your body, scientists have found that
only 50 per cent of cells in the body
are human – the rest are bacteria,
fungi, viruses and even microscopic
insects, living and breeding in every
crevice of our skin, mouths and gut.
Together, they are called the human
microbiome.
As humans have evolved so, too,
have these communities of tiny or-
ganisms. Different species have de-
veloped specialised roles in keeping
us alive – so much so that some sci-
entists believe human beings are
more like symbiotic organisms made
up of the human, the microbiome
and the surrounding environment,
says Loughman.
High-throughput DNA sequencing
has allowed scientists to identify 3.3ANCIENT GREEK
PHYSICIAN
HIPPOCRATES WAS
THE FIRST TO ALLUDE
TO THE VITAL ROLE
THE GUT PLAYS IN
GENERAL HEALTH
WHEN HE DECLARED,
“LET FOOD BE
THY MEDICINE”