John Vidal
Wednesday July 17, 2002
The Guardian

British scientific researchers have demonstrated
for the first time that genetically modified DNA
material from crops is finding its way into human
gut bacteria, raising potentially serious health
questions.

Although the genetically modified material in
most GM foods poses no health problems, many of
the controversial crops have antibiotic-resistant
marker genes inserted into them at an early stage
in development.

If genetic material from these marker genes can
also find its way into the human stomach, as
experiments at Newcastle university suggest is
likely, then people's resistance to widely used
antibiotics could be compromised.

The research, commissioned by the food standards
agency, is the world's first known trial of GM
foods on human volunteers. It was last night
described as "insignificant" by the agency but as
"dynamite" by Friends of the Earth.

The scientists took seven human volunteers who
had their lower intestine removed in the past and
now use colostomy bags. After being fed a meal of
a burger containing GM soya and a milkshake, the
researchers compared their stools with 12 people
with normal stomachs. They found "to their
surprise" that "a relatively large proportion of
genetically modified DNA survived the passage
through the small bowel". None was found in
people who had complete stomachs.

But to see if GM DNA might be transferred via
bacteria to the intestine, they also took
bacteria from stools in the colostomy bags and
cultivated them. In three of the seven samples
they found bacteria had taken up the
herbicide-resistant gene from the GM food at a
very low level.

The report added "that transgenes, although
surviving passage through the small intestine,
appear to be completely degraded in the human
colon".

Michael Antonio, a senior lecturer in molecular
genetics at King's College Medical School,
London, last night said that the work was
significant. "To my knowledge they have
demonstrated clearly that you can get GM plant
DNA in the gut bacteria. Everyone used to deny
that this was possible."

He said there were "lots of inadequacies" in the
research but that did not take away the
importance of the main findings. "It suggests
that you can get antibiotic marker genes
spreading around the stomach which would
compromise antibiotic resistance. They have shown
that this can happen even at very low levels
after just one meal."

Marker genes are inserted into GM plants to allow
identification of GM cells or tissue during
development. The House of Lords has called for
them to be phased out as swiftly as possible.

Last night Friends of the Earth called for an
immediate halt to the use of marker genes in GM
crops. "Industry, science and government advisers
have always played down the risk of this
happening and here, at the very first attempt by
scientists to look for it, they find it," said
Adrian Bebb, GM foods campaigner.

The FSA said the research "showed in real-life
conditions with human volunteers, no GM material
survived the passage through the entire human
digestive tract... the research concluded that
the likelihood of functioning DNA being taken up
by bacteria in the human or animal gut is
extremely low".

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