Mind, Mood & Microbes: scientific insights about the gut-brain connection

The gut-brain axis and the role of gut microorganisms in brain health was the focus of – the 5th edition of Mind, Mood & Microbes – held in February 2025 in Amsterdam. Over 200 academic and industry scientists, as well as clinicians and representatives of health organizations, gathered to discuss the latest developments in this field.

Scientific knowledge in this area is growing rapidly, with scientists from diverse specialties turning their attention to the gut-brain axis and leveraging technologies such as novel cell imaging techniques and sophisticated laboratory models of the brain.

Here are the most insightful learnings presented by the conference’s international group of experts.

Here are the most insightful learnings presented by the conference’s international group of experts.

Early life interventions to improve brain development and health

Keynote speaker Prof. Lindsay Hall researches preterm infants, a vulnerable population, and has discovered that beneficial gut microbes (Bifidobacterium) in these infants are often displaced by pathogens. Gut microbial disruptions in these infants are associated with gastrointestinal disease as well as brain damage. However, supplementing with specific Bifidobacterium strains may improve developmental outcomes by strengthening the gut’s resistance to pathogens.

Likewise, Prof. Antonio Suarez found associations between gut microbiota maturation and cognition in infants. A synbiotic intervention, delivered through formula, modified the gut microbiota and improved scores on a validated infant development scale.

Probiotics for mental health: finding appropriate outcomes

Prof. Charles Morin, one of the world’s leading experts in sleep disorders, emphasized quality sleep as a main pillar of health. He noted that many people are caught in a vicious cycle of stress, mood disturbance, and poor sleep. In a probiotic intervention trial for people experiencing work-related stress, those who took the probiotic experienced a noticeable reduction in non-clinical depressive symptoms, suggesting a benefit for mental well-being, even though sleep parameters remained unchanged.

Clinical psychologist and scientist Dr. Laura Steenbergen described another probiotic intervention that targeted cognitive reactivity to sad mood. Individuals showed no difference on validated questionnaires but those who took the probiotic subjectively reported fewer negative feelings. Dr. Steenbergen emphasized the importance of considering subjective (conscious) experiences when assessing mood-related outcomes, as they can provide valuable insights beyond objective measurements.

Diet can affect brain health by working together with specific gut microbes

The conference featured several examples of how dietary factors and gut microorganisms work together to impact brain disorders. Dr. Ashutosh Mangalam studied phytoestrogens in the diet, which require certain bacteria to be present in the gut to have a positive effect in models of multiple sclerosis. Dr. Mangalam stated that “the company the bacteria keep” is what enables them to make use of these dietary components – that is, a higher ratio of the bacterial groups Bifidobacterium to Akkermansia is associated with a better ability to metabolize phytoestrogens and reduce disease progression. Dr. Sid Venkatesh shared an example from malnourished children: when these children received a nutritional intervention, Faecalibacterium prausnitzii levels increased in their guts, producing metabolites that boosted appetite and helped normalize immune responses.

Potential biomarkers in depression research

Dr. Mireia Valles-Colomer found in a large cohort that depression and quality of life vary according to gut microbiome composition. Her team used data from large cohorts to correlate gut microbes and metabolites with mental wellness. Keynote speaker Prof. Madhukar Trivedi MD brought a clinical perspective on depression, noting that limited evidence exists on which treatment is best for each individual. He is studying brain images, gut microbiota, and other biological parameters in people with depression to identify a panel of measurements that help clinicians tailor depression treatments to a specific individual.

Clinical subgroups respond differently to gut-targeting treatments

Treatments targeting the gut microbiome, such as fecal microbiota transplantation (FMT) have been explored in trials of neurodegenerative diseases such as Parkinson’s disease, but the results so far have been mixed. Arnout Bruggeman’s presentation suggested that FMT may work for only a subgroup of individuals with Parkinson’s disease: interestingly, individuals with pathology originating in the brain (rather than ‘body-first’ pathology, which originates in the gut) appeared to show more improvements in motor symptoms after an FMT intervention.

The gut microbiome’s role in endocrine function makes it a promising target for brain-related symptoms during the female menopause transition

Dr. Siobhain O’Mahony noted that cognitive and mood changes are common during the female menopause transition, with sleep disturbances, anxiety, and brain fog being among the top complaints. The gut microbiome influences host estrogen levels through several mechanisms, and Dr. O’Mahony is leading the development of a probiotic intervention aimed at normalizing hormones and alleviating brain-related menopause symptoms.

The insights shared at Mind, Mood & Microbes present compelling examples of gut-targeting interventions that are making a tangible impact on brain health. These groundbreaking approaches open up a powerful new range of possibilities for restoring and maintaining mental well-being throughout life, offering hope for improved cognitive and emotional health at every stage.