Fermented food intake linked to fewer anxiety symptoms: Study

The study is said to be the first report connecting the consumption of natural fermented foods and anxiety, according to researchers from the College of William and Mary and the University of Maryland.

“It is likely that the probiotics in the fermented foods are favorably changing the environment in the gut, and changes in the gut in turn influence social anxiety,” ​said Professor Matthew Hilimire, lead author of the study. “I think that it is absolutely fascinating that the microorganisms in your gut can influence your mind.”​

Gut-brain axis​

Data from animal and human studies have suggested that probiotics may exert anti-anxiety benefits, and a recent review published in the Neuropsychiatric Disease and Treatment​ ​by Linghong Zhou and Jane Foster from McMaster University in Canada Using said that probiotics and prebiotics may alter the gut microbiota and influence the gut-brain axis to possibly open up new ways of influencing neuropsychological conditions.

On the other hand, no studies have looked at the potential relationship between probiotics and social anxiety, explained the authors in Psychiatry Research​.​

Prof Hilimire and his co-workers designed a questionnaire that was included in a mass testing tool administered in the university’s Introduction to Psychology courses during the fall 2014 semester; 710 students participated, 445 of whom were women. The questionnaire asked students about the fermented foods over the previous 30 days; it also asked about exercise frequency and the average consumption of fruits and vegetables so that the researchers could control for healthy habits outside of fermented food intake.

“The main finding was that individuals who had consumed more fermented foods had reduced social anxiety but that was qualified by an interaction by neuroticism,” ​said Hilimire. “What that means is that that relationship was strongest amongst people that were high in neuroticism.”​

The researchers also found that more exercise was related to decreased social anxiety.

The study is just the first in a series to exploring the gut-brain connection, said Hilimire, and an experimental version of the study will also follow to allow them to elucidate if there is a causal relationship between eating fermented foods and reduced social anxiety.

“However, if we rely on the animal models that have come before us and the human experimental work that has come before us in other anxiety and depression studies, it does seem that there is a causative mechanism,”​

he said. “Assuming similar findings in the experimental follow-up, what it would suggest is that you could augment more traditional therapies (like medications, psychotherapy or a combination of the two) with fermented foods – dietary changes – and exercise, as well.”​

“These initial results highlight the possibility that social anxiety may be alleviated through low-risk nutritional interventions, although further research is needed to determine whether increasing probiotic consumption directly causes a reduction in social anxiety,” ​added Jordan DeVylder, co-author of the paper.

Source: Psychiatry Research​​
15 August 2015, Volume 228, Issue 2, Pages 203–208 
“Fermented foods, neuroticism, and social anxiety: An interaction model”​
Authors: M.R. Hilimire, J.E. DeVylder, C.A. Forestell