Communication between the brain and the gut goes far beyond the “stomach grumbling” heard by your head when it’s hungry.
Indeed, the discovery of a gut-brain axis is opening new avenues for questions on how the microbiota may influence the brain response to stress and its expression as anxiety, mood disorders or depression.
Researchers at the University of Oxford together with other agencies in the United Kingdom noted from the literature that prebiotic fibers were able to have significant neurobiological effects in rats and investigated whether similar response would be observed in humans.
Forty-five healthy volunteers received one of two prebiotics or placebo daily for 3 weeks. Fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS) were the prebiotics used.
- Cortisol in saliva was lower after B-GOS.
- The volunteers taking B-GOS increased processing of positive as opposed to negative information.
- Volunteers taking FOS showed no change from placebo.
The authors wrote:
“Our effects are similar to those seen following administration of pharmacological agents such as the selective serotonin reuptake inhibitor citalopram or the benzodiazepine diazepam in healthy individuals.”
In conclusion, they wrote:
“We found a selective modulation of attention to emotional stimuli and HPA axis reactivity following B-GOS prebiotic supplement in healthy participants, supporting a key role for gut microbiota in the regulation of affective function. This, to our knowledge, is the first study extending findings of the central effects of probiotics to behavioural effects of prebiotics in humans.”