This calorie-restricted group, the researchers found, had a far richer and more diverse microbial community in the gut than those eating a typical American diet.
Only 7.5 percent of mice on the calorie-restricteddiet developed pancreatic lesions at the end of the experiment, and these lesions were so small that none exhibited symptoms of illness.
The research started with 30 rhesus macaques in 1989 to chart the health effects of a calorie-restricteddiet and expanded in 1994 with the addition of 46 more.