by John Vidal
July 17, 2002
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
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
They found “to their surprise” that,
“a relatively large proportion of
genetically modified DNA survived the passage through the small
None was found in people who had
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 Antoniou, 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
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”.
Subj: Qs about FSA studies on GM transfer
Date: 16/07/02 19:49:09 GMT
From: firstname.lastname@example.org (Robert Vint)
As genuine independent published
peer-reviewed research on GM foods is virtually non-existent, it
would be interesting to find out in relation to this FSA
Whether it was carried out
by genuinely independent scientists or by scientists
from institutes funded by the biotech industry.
Whether research carried out
for other EU governments less keen to promote GM crops
has reached similar conclusions.
Whether the full data from
the research will be published and peer reviewed - and
whether the FSA has asked the BMA, which has great
concern about this issue, to evaluate it.
Whether the human volunteers
were diverse - whether they included people of different
races, the elderly and children and those in poor
I’m not a scientist but my concerns
would be as follows:
The conclusion that GM material
- such as antibiotic resistance marker genes - does not
survive the journey through the human digestive system or
get incorporated into bacteria might well not be true for
people in poor health unless this is specifically tested.
Children and the elderly and people in poor health might be
more vulnerable for a wide variety of reasons.
Poor digestive systems, weak
stomach acids or diarrhea could allow DNA to pass more
rapidly through the system with less damage to it. Poor
immune systems could allow far more bacteria to survive.
Viral infections could be the vector responsible for
transferring genetic material from food to bacteria.
Damage to the intestine caused
by infection could make the transfer of bacteria into the
body far easier.
There are parts of the world - such
as Southern Africa - where 20-50% of the population are HIV
These people have very poor immune
systems, an active virus in their bodies, they commonly have
diarrhea and a wide range of infections. Whilst healthy well-fed
westerners in their twenties might be at low risk from any gene
transfer danger this might not be true for the people of
Southern Africa on whom the USA is dumping vast quantities of
unwanted GM maize.
It only needs one of the billions of
bacteria in the intestines of one of these millions of highly
vulnerable people to acquire the antibiotic resistance gene for
a new antibiotic resistant bacterial strain to emerge.
Can we be THAT sure it won’t happen?
"Swapping genes between organisms can produce unknown toxic
effects and allergies that are most likely to affect
- Dr Vyvyan Howard
expert in infant toxico-pathology
at Liverpool University, UK.
(Ref: The Guardian: 19/3/98)