Enlisting Gut Bacteria in the Fight Against Obesity

What’s the Latest?

An imbalance of gut bacteria may play an important role in America’s obesity problem, in addition to its addiction to innutritious food and sedentary lifestyles. “In studies of twins who were both lean or both obese, researchers found that the gut community in lean people was like a rain forest brimming with many species but that the community in obese people was less diverse—more like a nutrient-overloaded pond where relatively few species dominate. Lean individuals, for example, tended to have a wider variety of…microbes that specialize in breaking down bulky plant starches…that the body can use as a source of energy.”

What’s the Big Idea?

The gut ecosystem is strongly shaped by an individual’s diet. Highly processed foods, for example, have been linked to a less diverse pool of gut bacteria. In an experiment, mice were fed an especially unhealthy diet that was high in fat and low in fruits, vegetables, and fiber. “Given this ‘Western diet,’ the mice with obese-type microbes proceeded to grow fat even when housed with lean cagemates. The unhealthy diet somehow prevented the virtuous bacteria from moving in and flourishing.” If scientists can determine the precise gut bacteria associated with leanness, it may be possible to implant the bacteria into obese individuals.