A new method for identifying plant foods developed by scientists at Duke Medical School could bridge the gap between what people say they ate and what they actually ate. This genetic breakthrough could have a wide range of applications, including improving the accuracy of clinical trials and nutritional research.
The researchers used DNA barcoding technology, which is based on previous studies comparing DNA found in feces with reported diets. They have developed a genetic marker for plant-based foods that allows them to determine which foods have been eaten. This marker is based on a specific stretch of DNA that plants use to feed their chloroplasts.
The team of scientists tested their marker on more than 1,000 fecal samples from 324 participants in various studies. They found that the DNA markers not only indicated which foods were consumed, but could also determine the relative amounts of specific foods. The researchers also observed that a person’s diet, age and family income affect the variety of plant DNA found in their feces.
For the study, the team used a reference database containing markers for 468 plant species commonly consumed by Americans. Their DNA barcoding method distinguished 83 percent of all major crop families. However, the scientists note that people in other parts of the world consume other crop families that are currently undetectable. Professor David’s lab is working to add crops such as millet and pili nuts to their database.
The scientists also intend to extend their DNA barcoding technique to track meat consumption. They believe that this relative ratio of plant and animal consumption is one of the most important nutritional factors to watch out for.
The team of scientists also applied their technique to fecal samples of weight-loss program participants. They determined exactly what the participants had been fed a day or two before. For example, they looked for markers of components of a dish called wild rice mushroom pilaf in the fecal samples after it was served.
This new method of identifying plant-based foods could have a significant impact on various areas related to nutrition and health. It could help improve the accuracy of clinical trials, nutritional studies and more. With this technology, we can get more accurate information about what people are eating and how it affects their health.
