New research published in nutritional neuroscience How do probiotic supplements, prebiotic-enriched diets, or their combination (synbiotic treatment) affect cognitive function in adults who are less likely to improve their mood or diet? We investigated. This randomized controlled trial provides preliminary evidence that probiotic supplementation may improve working memory. However, the findings are preliminary and the researchers emphasize the need for larger studies to confirm these effects.
In recent years, there has been increasing interest in the potential link between the gut-brain axis and cognitive performance. The gut-brain axis is a complex bidirectional communication system between the digestive system and the brain, mediated through neural, hormonal, and immune pathways.
At the heart of this connection is the gut microbiome (trillions of microorganisms that live in the gastrointestinal tract), which play a key role in influencing brain function and behavior. These microorganisms produce a variety of metabolites, such as short-chain fatty acids and neurotransmitters, that regulate inflammation, influence mood, and influence cognitive processes such as memory and attention.
One way to influence your gut flora is through the use of probiotics. Probiotics are live microorganisms that provide health benefits when taken in appropriate amounts. Probiotics, commonly taken through supplements and fermented foods such as yogurt and kefir, can help restore balance to the gut microbiome, increase production of beneficial metabolites, and reduce inflammation.
Some studies suggest that probiotics may improve cognitive function by targeting pathways associated with mood and brain health, especially under stress or in clinical populations. However, other studies have reported little or no improvement in cognitive function with probiotic use, and the evidence remains inconsistent.
In addition to probiotics, prebiotics (nondigestible dietary fiber that feeds beneficial gut bacteria) have also been studied for their effects on the gut-brain axis. Prebiotics, naturally found in foods such as whole grains, vegetables, fruits, nuts, and legumes, promote the growth and activity of healthy gut bacteria and produce compounds such as short-chain fatty acids that support brain function. It leads to
Prebiotic supplements have shown potential to improve aspects of cognition and mood, but much of the research relies on single supplements rather than whole-food approaches. This distinction is important because diets rich in prebiotic foods may have broader and more sustainable benefits for gut health.
To better understand whether gut-focused interventions lead to measurable improvements in mental health, researchers behind a new study looked at adults who were depressed and depressed. They designed an 8-week randomized controlled trial comparing probiotic supplements, prebiotic-enriched diets, and their combinations. There is room for improvement in eating habits.
“We were inspired by SMILES TrialThis was the first RCT to demonstrate a strong potential for diet to improve symptoms of depression. Around the same time, we noticed a growing body of literature on the effects of probiotic and prebiotic supplements on mental health, providing evidence for the involvement of the gut-brain axis.” said Tanya Fryge, doctoral candidate and study author. in Neuroscience and Mental Health from the University of Melbourne, Australia.
“However, there has been a gap in whole-food approaches to improving gut health and, by extension, mental health. We consulted with Professor Muir and adapted this diet for use in our research.”
The study included 118 adults between the ages of 18 and 65 who reported moderate psychological distress and low intake of prebiotic fiber in their daily diet. To participate, participants had to meet certain health criteria before the trial, including avoiding probiotic supplements and fermented foods. Exclusion factors include gastrointestinal disease, psychiatric illness, pregnancy, or use of certain medications.
Participants were randomly assigned to one of four groups:
- probiotics group: I took probiotic supplements while maintaining my normal diet.
- prebiotic diet group: I followed a prebiotic-enriched diet and received a placebo capsule.
- symbiotic group: I took both a probiotic supplement and a high prebiotic diet.
- Placebo group: I took a placebo capsule and continued my normal diet.
At the beginning and end of the study, participants completed a cognitive assessment using the Cogstate Brief Battery, a computerized test that measures processing speed, attention, visual learning, and working memory. Performance was evaluated based on reaction time and accuracy.
Probiotic supplementation appears to have the most promising, albeit modest, effect. The results suggested that working memory, one of the core cognitive functions involved in short-term information retention and manipulation, may be improved. Participants in the probiotic group showed modest improvement compared to the placebo group.
“However, this evidence is not conclusive until it is replicated in a larger study, ideally using more complex measures of cognition,” Fryjay told PsyPost.
In contrast, the prebiotic-rich diet showed weak evidence that processing speed, which measures how quickly and accurately participants can respond to simple tasks, was impaired. The prebiotic group performed slightly worse than the placebo group. However, the researchers cautioned that this finding may be a statistical anomaly rather than a true adverse effect, as previous studies have not reported any cognitive impairment due to prebiotics.
“The reduction in processing speed caused by prebiotics is unexpected and contradicts the positive effects of the same dietary intervention on mood, anxiety, sleep, and perceived stress.” our previous publications” Freige explained. “A closer look at the data shows that this finding is most likely due to chance.”
There was no clear evidence of synergistic or additive effects when looking at the synbiotic group that combined probiotic supplementation with a prebiotic-enriched diet. In other words, combining the two interventions did not produce stronger cognitive outcomes than either treatment alone. The results showed that when the effects of probiotic and prebiotic interventions existed, they were independent and there were no significant interactions.
“Another unexpected finding was the lack of cognitive benefit from synbiotic treatment (high prebiotic diet and probiotic supplements), contrary to our expectations that it would be more effective than other interventions. That was the case,” Fryjay said.
The researchers noted several limitations that may have affected their findings. For example, the sample size was relatively small, and the study was not specifically designed to measure cognitive effects. Furthermore, because the participants were generally healthy adults with no clinical symptoms, their cognitive abilities may have been close to their natural upper limit. This may limit the scope for detecting improvements.
Despite these challenges, the researchers are optimistic about the far-reaching impact of their work. “We hope to link the microbiome analysis from this project (currently in preparation) with observed changes in mental health and cognition,” Fryjay told PsyPost. “We look forward to publishing our microbiome findings in the future and will also provide further details on the feasibility of high-prebiotic dietary protocols and diets to inform future research and potentially clinical practice.” There is also a goal.”
“This study is part of our larger gut-brain project, the Gut Feelings trial. primary publication Information about the mental health impact of our clinical trials is available for free online. What we recommend is: food and mood centerDeakin University serves as a resource to learn about the latest research being conducted in the field of nutritional psychiatry and nutrition-based approaches to the prevention and treatment of mental disorders. ”
the study, “Effects of a prebiotic-rich diet and/or probiotic supplements on human cognition: Secondary results of the “Gut Feelings” randomized controlled trial” is written by Tanya M. Fryge, Lachlan Cribb, Georgina Oliver, Najwa Joel Metri, Rachel S. Opie, Felice N. Jacka, Jason A. Hawlerak, and Julia J. Ruckridge. , Chi H. Ng, and Jerome Sallis.
