How do fermented foods affect brain function?

Fermented foods are ingrained in many cultures and diets, offering a method of preserving food. Recently, the consumption of fermented products has become increasingly popular following myriad research suggesting that they contain health benefits.

Fermented foods are a source of tryptophan, an amino acid key to the production of serotonin, a brain messenger known as a ‘happy hormone’ for its influence on several aspects of brain function, including mood. Other brain messengers, or neurotransmitters, can also be found in fermented foods. This suggests that they might have long- and short-term impacts on brain function, such as stress reduction.

Researchers at APC Microbiome, University College Cork and Teagasc in Ireland are working on a study to find which fermented foods have the most impact on brain function.

Ramya Balasubramanian and her team compared sequencing data from over 200 foods from all over the world, looking for a variety of metabolites known to be beneficial to brain health.

Though still in its initial stages, preliminary results from the study have surprised researchers, with the majority of foods tested showing some potential to improve gut and brain health. More research is needed to fully understand which foods have the greatest effects, but early results have shown an unexpected victor.

According to Balasubramanian, fermented sugar-based and vegetable-based products had the greatest effect.

“For all that we see on sugar-based products being demonised, fermented sugar takes the raw sugar substrate and it converts it into a plethora of metabolites that can have a beneficial effect on the host. So even though it has the name ‘sugar’ in it, if you do a final metabolomic screen, the sugar gets used by the microbial community that’s present in the food, and they get converted into these beautiful metabolites that are ready to be cherry picked by us for further studies,” she said.

Balasubramanian intends to put the top ranked foods through further rigorous testing using an artificial colon and various animal models to see how they affect the brain.

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