Low-Calorie Longevity May Be Linked to Gut Bacteria

Many animals on low-calorie diets live longer than their traditionally fed counterparts, and British scientists suspect that stomach bacteria may play a part in this.

In a recent study of Labrador retrievers placed on low-calorie and regular diets, scientists found that the low-calorie dogs lived an average of two years longer. They also noticed that these dogs had low levels of creatine derivatives and aliphatic ampines.

Creatine is a substance that supplies energy to muscles; lower derivative levels suggested a reduced metabolism. Aliphatic amines are made when bacteria eat choline, a compound used to metabolize fat. Lower amine levels suggeted lower levels of choline -- so much lower, said the researchers, that it couldn't be explained by diet alone, and may have been linked to a diet-related change in the dogs' stomach bacteria.

That result, if true, echoes one published a few months ago by Jeffrey Gordon of Washington University, in St Louis. He showed that putting obese people on a diet changes the mix of their gut bacteria. In that case the consequence is a change in the metabolism of carbohydrates rather than fats. Nor was there a direct link with longevity of the sort implicit in Dr Nicholson's work. Nevertheless, the parallel is intriguing—and yet another incentive to cut down on the calories.

A Dog's Life [The Economist]
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Image: John*