As the brain-gut connection comes into sharper focus, new insights into obesity are emerging. A recent study has found that dietary fiber's role in weight loss, commonly attributed to releasing appetite-suppressing hormones in the gut, may be a matter of the mind. As Nature News reports, researchers from the UK and Spain showed in a study in mice how a product of fiber fermentation reduced food intake by influencing a region of the brain.
From the piece:
[The researchers] fed mice fibre labelled with carbon-13, which has an additional neutron from the more common carbon-12 that gives its nuclei a magnetic spin and therefore makes it easy to track as it progresses through the body's chemical reactions. The fibre was fermented as usual into acetate, which turned up not only in the gut, but also in the hypothalamus, a part of the brain known to be involved in regulating appetite. There, the researchers found, it was metabolized through the glutamine-glutamate cycle, which is involved in controlling the release of neurotransmitters associated with appetite control. The same model has been proposed for acetate metabolism after drinking alcohol.
The mice fed with large doses of fermentable fibre ate less food, and ended up weighing less than control mice that were fed unfermentable fibre.
The article notes the researchers plan to investigate enriching fiber with acetate to aid digestion and appetite control. “It’s sort of a way of having your cake, and not eating it,” said Jimmy Bell, PhD, one of the study's researchers and a biochemist at Imperial College London.