Study shows disadvantages of GM foods to human health

British scientific researchers demonstrated that genetically modified DNA from crops can find its way into human gut bacteria, raising possible health concerns. This is because antibiotic-resistant marker genes are inserted with GM material, which could cause a person to be resistant to antibiotic medicines.

The study was conducted at Newcastle University on seven human volunteers who, in the past, had their lower intestine removed and now use colostomy bags. After eating a burger containing GM soy, 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. To see if GM DNA might be 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.

Michael Antonio, a senior lecturer in molecular genetics at King`s College Medical School, London, said that the work was significant because the researchers demonstrated that you can get GM plant DNA in the gut bacteria, which was previously considered to be not possible. Antonio said the research suggests that antibiotic marker genes could spread around the stomach and compromise antibiotic resistance. If this were to happen, a person could be immune to beneficial antiobiotic medicines.

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. The research was conducted at the request of the UK's Food Standards Agency, which released a statement saying the research, "concluded that the likelihood of functioning DNA being taken up by bacteria in the human or animal gut is extremely low."

Source: The Guardian
(August 2002)