Does the gut microbiome hold clues to obesity and diabetes?

had an equivalent negative impact. Indeed, participants in a 2007 workshop sponsored by the National Academy of Sciences, entitled ‘Genetically Engineered Organisms, Wildlife, and Habitat’, agreed on the importance of proper comparisons. Referring to the findings of meeting participant LaReesa Wolfenbarger from University of Nebraska, a summary of the workshop said, “The conclusion Wolfenbarger drew from these studies was that GE crops do affect wildlife food, but that variations in agricultural practices, including cultivation itself, and the use of insecticides, can have larger effects.” The other significant concern among environmentalists and scientists alike is the potential for gene flow between GM crops and wild flora to erode biodiversity. The worry is that if GM crops are grown in close proximity to wild species that are closely related, hybridization between the two could lead to genetic contamination. This is especially likely if the gene introduced into the wild population confers a fitness advantage, allowing it to spread via natural selection. The issue has been of particular concern in places like Mexico where numerous landraces of maize and its wild progenitors are grown next to each other. In fact, the Mexican government has banned the planting of GM maize since 1998. Despite the ban, several recent studies have found evidence of GM genetic material in cultivated maize grown in Mexico, though it’s unclear from where this material originated. At this stage, there are many unknowns when it comes to the potential impact on biodiversity. In those cases where the potential for hybridization is low, such as maize grown in the US, the risk is likely minimal. But what about crops like sunflowers, pecans, blueberries, and some squashes, which are native to the US? Should GM versions of these crops emerge, is there cause for concern? As advocated in the 2007 workshop, when the potential for hybridization does exist, it will be necessary to both quantify the extent of gene flow between populations and, importantly, assess the potential fitness advantages conferred by the genes in question. However, as in the question of food safety, it’s not clear that the environmental issues raised by GM crops should be any different from traditionally created varieties. Both have the potential to affect wild gene pools. Weighing the risks As with any technology, at some point there has to be a cost/benefit analysis done. While all of the food safety scares surrounding GM food continue to be debunked as fast as they materialize, there are no doubt potential risks that are not yet fully understood, as can be seen in the ecology aspect of the debate. And there is nothing to say that new varieties of GM food could, in principle, potentially be harmful. On the other side of the ledger, however, we have the enormous challenge of feeding the world’s population, which is rapidly growing on a planet with finite resources. Of course, malnourishment has many causes, including local politics and war, but agricultural technology will certainly factor importantly. And GM food has lived up to its promise of providing increased yields with less pesticide use and at a lower cost to the consumer. Not only this, but genetic engineering has the potential to provide much needed micronutrients (i.e., vitamins) to the malnourished of the world. A case in point is the recent development of an engineered form of rice that produces a precursor of vitamin A, dubbed ‘golden rice’. This remarkable and easily implementable technology has the potential to mitigate hundreds of thousands of cases of blindness in the developing world, and yet it remains shelved due to unsubstantiated health concerns. Many western consumers can afford to stock their refrigerators with organic produce, but can the rest of the world? Do the potential risks really trump malnourishment and starvation? While the interested parties continue to debate, science marches on. On the horizon are GM crops that can grow in inhospitable corners of the earth, such as the dry and salty environs. And we are now seeing the application of GM technology to animals, such as salmon engineered to reach market weight more quickly through the expression of genes encoding growth hormones. Whether these technologies are taken up or left to gather dust on the shelf will likely depend on the ability of scientists and the government to make a convincing case to the public. If they fail, we potentially handcuff ourselves and will be forced to rely on 20th century technology to solve 21st century problems.