Methionine breakdown for weight loss in mice

What's the news: Obese mice lost weight when fed a probiotic that breaks down methionine.

Why should we believe it: This news is based on a study that is set to be published on June 9 by a team of scientists from Japan and UC San Diego.

The scientists compared the effect of a methionine-restricted diet to a diet supplemented with unique probiotic bacteria. This probiotic bacteria produces an enzyme that breaks down methionine before it can be absorbed into the body.

While the methionine-restricted diet resulted in greater total weight loss, the probiotics also reduced weight, while providing a more practical and broadly applicable solution.

Why this is a big deal: Methionine is an essential amino acid, meaning our bodies require a certain level of it in the diet. At the same time, methionine restriction has been shown, in both humans and mice, to mimic the effects of overall calorie restriction, without the need for actual long-term restriction of calories.

The trouble is, methionine is a component of all proteins. Completely eliminating it from the diet is highly impractical — it’s to be found in meat, cheese, nuts, whole grains. However, the present study presents an alternative way to reduce methionine levels in the body without reducing it in the diet.

So what’s next? A similar probiotic is already being tested in humans. By ingesting such a probiotic, or the enzyme it produces directly, we might soon be able to get the youthspan benefits of calorie restriction or methionine restriction — without restricting anything at all.