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New study shows stress can be reduced by a psychobiotic diet

27 Oct 2022
Professor John Cryan and Professor Ted Dinan (Photograph: Clare Keogh)

• Researchers at APC Microbiome Ireland have proven that food can change mood.
• A psychobiotic diet decreased stress and depressive symptoms in healthy volunteers.
• The findings reveal potential ways to manage and reduce stress through nutrition.

Researchers at APC Microbiome Ireland, a world-leading SFI research centre based at University College Cork (UCC), have announced a breakthrough for stress management based on the influence of a psychobiotic diet. The findings reveal potential ways to reduce stress and stress-associated disorders through microbiota-targeted diets which are high in prebiotic and fermented foods.

The study, which further investigates the link between microbiome, gut function and stress, is published in Molecular Psychiatry.

Researchers studied participants with relatively low fibre diets and measured their perceived levels of stress. Dr Kirsten Berding, nutritionist and Irish Research Council Postdoctoral Fellow, collaborated with neuroscientist Professor John Cryan and psychiatrist Professor Ted Dinan to design a diet that was high in prebiotic and fermented foods.

Participants were educated on the study diet*, which included consumption of fruit and vegetables high in prebiotic fibres, grains and legumes as well as fermented foods, e.g. sauerkraut, kefir or kombucha. Those on the control diet received general dietary advice according to the food pyramid.

The study found that those following the psychobiotic diet for a period of four weeks experienced a reduction of perceived stress, with those who most closely followed the psychobiotic diet experiencing stronger decreases in perceived stress. Significant changes in the level of forty chemicals were analysed, while only subtle changes in microbial composition and function were observed. The quality of sleep improved in both the treatment group and the control group. The results highlight that dietary approaches can be used to reduce perceived stress in a human population.

Professor John Cryan, Vice President for Research & Innovation UCC, Principal Investigator, APC Microbiome Ireland, and one of the study’s lead authors: “Although the microbiome has been linked to stress and behaviour previously, it was unclear if by feeding these microbes demonstratable effects could be seen. Our study provides one of the first data in the interaction between diet, microbiota and feelings of stress and mood. Using microbiota targeted diets to positively modulate gut-brain communication holds possibilities for the reduction of stress and stress-associated disorders, but additional research is warranted to investigate underlying mechanisms.”

Professor Ted Dinan, Professor of Psychiatry, Principal Investigator in APC Microbiome Ireland and co-lead author, said: “As a psychiatrist, I am conscious of the fact that psychiatrists rarely give patients dietary advice. Our research in recent years provides evidence that an appropriate diet is essential in managing stress-related disorders. Hopefully, the current paper will encourage psychiatrists to include nutritional advice as part of holistic patient management.”

* The study diet included consumption of fruits and vegetables high in prebiotic fibers (6–8 servings per day, e.g., onions, leeks, cabbage, apples, bananas, oats), grains (5–8 servings per day) and legumes (3–4 servings/week) as well as fermented foods (2–3 servings per day, e.g., sauerkraut, kefir or Kombucha).

University College Cork

Coláiste na hOllscoile Corcaigh

College Road, Cork T12 K8AF

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