Intermittent fasting helps change the activity of gut bacteria and increase their ability to recover from nerve damage, according to a study conducted in mice.
Researchers from the Imperial College London observed how fasting led to the gut bacteria increasing production of a metabolite known as 3-Indolepropionic acid (IPA), which is required for regenerating nerve fibres called axons -- thread-like structures at the ends of nerve cells that send out electro-chemical signals to other cells in the body.
This novel mechanism was discovered in mice and is hoped to also hold true for any future human trials. The team states that the bacteria that produces IPA - named Clostridium sporogenesis -- is found naturally in the guts of humans as well as mice; and IPA is present in human's bloodstreams too.
"There is currently no treatment for people with nerve damage beyond surgical reconstruction, which is only effective in a small percentage of cases, prompting us to investigate whether changes in lifestyle could aid recovery," said Professor Simone Di Giovanni from Imperial's Department of Brain Sciences.
"Intermittent fasting has previously been linked by other studies to wound repair and the growth of new neurons - but our study is the first to explain exactly how fasting might help heal nerves,"Di Giovanni added.
The study, published in the journal Nature, assessed nerve regeneration of mice where the sciatic nerve -- the longest nerve running from the spine down the leg -- was crushed. Half of the mice underwent intermittent fasting (by eating as much as they liked followed by not eating at all on alternate days), while the other half were free to eat with no restrictions at all.
These diets continued for a period of 10 days or 30 days before their operation, and the mice's recovery was monitored 24 to 72 hours after the nerve was severed.
The length of the regrown axons was measured and was about 50 per cent greater in mice that had been fasting.
Importantly, when IPA was administered to the mice orally after a sciatic nerve injury, regeneration and increased recovery was observed between two and three weeks after injury.