Scientists link weight to gut bacteria:
In one of the two studies in Nature, Gordon and colleagues looked at what happened in mice with changes in bacteria level. When lean mice with no germs in their guts had larger ratios of Firmicutes transplanted, they got “twice as fat” and took in more calories from the same amount of food than mice with the more normal bacteria ratio, said Washington University microbiology instructor Ruth Ley, a study co-author.It was as if one group got far more calories from the same bowl of Cheerios than the other, Gordon said.
In a study of dozen dieting people, the results also were dramatic.
Before dieting, about 3 percent of the gut bacteria in the obese participants was Bacteroidetes. But after dieting, the now normal-sized people had much higher levels of Bacteroidetes — close to 15 percent, Gordon said.