Ridaura, V. K., et al. “Gut Microbiota from Twins Discordant for Obesity Modulate Metabolism in Mice.” Science, vol. 341, no. 6150, May 2013, pp. 1241214–1241214., doi:10.1126/science.1241214. <http://science.sciencemag.org/content/341/6150/1241214.full>
The article entitled, “Gut Microbiota from Twins Discordant for Obesity Modulate Metabolism in Mice,” published in the journal Science, is about the effect of gut bacteria on obesity. Researchers found sets of human twins in which one of the twins was thin and the other obese. The scientists then transferred the twins’ fecal bacteria to several mice that were also genetically identical. (Genetically identical mice—as well as humans—were important because genetic and environmental factors had to be controlled.) Also, the mice were raised in a sterile environment so they lacked any bacteria of their own. Approximately five weeks after the mice were given gut bacteria from the human twins, those that were given bacteria from obese twins had 15 to 17 percent more fat than those that were given bacteria from thin twins.
The next stage of the experiment involved placing mice with bacteria from thin twins in a cage with those that had gut bacteria from obese human twins. Mice ate each other’s droppings, so the researchers were curious to see if the gut bacteria would mix. To their surprise, the mice that initially had bacteria from the obese twins started losing weight as they consumed feces of mice that initially had bacteria from the thin twins.
Lastly, the researchers decided to vary the types of diets that the mice had. Fat mice that ate foods high in fat retained the gut bacteria they acquired from the obese twins and remained fat. Only fat mice that ate food high in vegetables and fruits had an increase in gut bacteria from the lean human twins.
