Researchers at Imperial College London showed that intermittent fasting increased the production of the antioxidant 3-indolepropionic acid in mice, thereby accelerating nerve fiber regeneration in mice. The study was published in the journal Nature.
Scientists conducted an experiment on rats that artificially injured the longest nerve that runs from the spine down the leg – the sciatic. Half of the mice were allowed to eat without restriction. The other half had to do intermittent fasting: one day they ate as much as they wanted and the next day they ate nothing. The regrowth axons were approximately 50% longer in length in intermittently starved mice.
The study’s authors hypothesized that this effect was due to an increase in 3-indolepropionic acid (IPA) synthesis by the bacterium Clostridium sporogenesis. This substance is necessary for the regeneration of axons, which are thread-like structures at the ends of nerve cells that send electrochemical signals to other cells in the body. IPA-producing bacteria have also been found in the human gut.
To confirm their hypothesis, they killed the mice’s microbiome with antibiotics. The scientists then introduced conventional and genetically modified strains of Clostridium into the intestines of mice that were unable to produce IPA. If bacteria do not produce IPA, regeneration is impaired, which supports its key role in nerve regeneration.
Oral administration of IPA also worked, so the researchers plan to further test this mechanism in spinal cord injuries in mice and find optimal doses. More research will be needed to learn whether IPA increases after fasting in humans and how this affects nerve regeneration.
Currently, people with nerve damage are treated with surgical reconstruction, which is effective in only a small percentage of cases. The effect of rapid nerve recovery for intermittent fasting has been demonstrated before, but this study is the first to describe the mechanism.
The study also included employees from the University of Miami Medical University, the Weizmann Rehovot Institute, the University of Lille, the Albert Einstein College of Medicine, and the Stanford School of Medicine.