Fears that genes for antibiotic resistance could jump from genetically modified foods to bacteria in the gut may be fueled by new research from the Netherlands.
The results show that DNA lingers in the intestine, and confirm that genetically modified bacteria can transfer their antibiotic-resistance genes to bacteria in the gut. Using an "artificial gut", researchers showed that DNA remains intact for several minutes in the large intestine.
One concern about some genetically modified (GM) crops, such as maize used as animal fodder, is that they include a gene for antibiotic resistance. The resistance genes are used to track the uptake of modified genes, and are not expressed in the crops.
While some scientists fear that these genes could jump into bacteria in the guts of livestock and create antibiotic-resistant pathogens, others have said there is no such risk because the modified DNA breaks down quickly. The Dutch results cast doubt on these assurances.
If the modified bacteria were a type normally found in the gut, such as Enterococcus, the experiment showed each had a 1 in 10 million chance of passing DNA containing antibiotic-resistance genes to an indigenous gut bacterium when they came in contact.
There are normally around a thousand billion gut bacteria, suggesting many would be transformed. If some normal gut inhabitants were killed off -- as in the guts of people or animals on antibiotics -- the transfer rate from gut-type bacteria increased tenfold.
New Scientist, 30 January 1999
Dr. Mercola's Comment:
This type of research is important in light of the new seeds that are being developed by Monsanto that are called Terminator genes. The seed companies produce hybrid seeds with highly sought after characteristics. They sell the seeds to the farmers who promise not to grow plants with the seeds produced with their harvest and to repurchase them from the seed company.
We all know that would not be a wise commercial decision for the farmer, so the seed company decided to sterilize all future seeds that the crops would produce by adding new genes to the seeds that would make the subsequent crops infertile.
This way, the farmer would be forced to repurchase their seeds from the seed company. Unfortunately, it appears that there is a small risk: these "terminator" genes can now be partially transferred during the digestive process.