Dr. Julia Rode, associate senior lecturer at Örebro University, Sweden, presented on stage at the recent IPA World Congress + Probiota 2025, hosted by NutraIngredients, having been selected as “Industry Winner” for her submission to the scientific abstract competition.
As lead author on the research, she explained that her team set out to explore the potential of microencapsulation for probiotics to achieve different delivery mechanisms and assess its impact on the gut, body systems and brain.
Exploring the gut-brain connection
As Rode told the audience, past research shows that gut microbiota plays a crucial role in mental health. An imbalance in gut bacteria, known as dysbiosis, is linked to conditions like depression, anxiety, ADHD and dementia.
Studies have confirmed that some probiotic strains may help reduce depressive symptoms, particularly when taken alongside antidepressants, she said. While research on anxiety remains mixed, probiotics consistently show positive effects on stress-related symptoms.
Neuroimaging techniques could provide valuable insights into how probiotics impact brain function, Rode explained. Past studies have revealed that probiotics can alter brain activity, especially in regions related to emotional regulation.
And in previous research, participants taking probiotics show improved mood and resilience to negative emotions, and these brain activity changes often correlate with self-reported improvements in well-being.
Study details
Rode and her team conducted a randomized, double-blind, placebo-controlled trial where they assessed two different probiotic formulations over six weeks. The two formulations were: one in its natural, powder form (non-encapsulated) and the other in an encapsulated form, both containing the same probiotic strain, dose and duration of intervention.
The study investigated the effects of Lactobacillus rhamnosus probiotic supplementation on brain health in elderly individuals (60 to 80 years old) using advanced imaging technology.
Participants underwent assessments at baseline, three weeks and six weeks, measuring brain connectivity, cognitive function and mental health indicators like anxiety, depression and sleep quality. Results showed that both probiotic formulations influenced brain connectivity but affected different neural circuits. Structural brain changes were also observed.
The findings suggest that the two probiotic formulations had distinct effects on gut health. Elderly participants responded differently to both probiotic interventions compared to the placebo, and there were notable differences between the two probiotic formulations.
“While we expected a difference in the magnitude of the effects, we instead observed that different physiological points were affected by the varying formulations,” Rode said. “This was evident through new imaging techniques we employed.”
Functional magnetic resonance imaging
The team used functional magnetic resonance imaging (fMRI) to focus on both whole-brain functional connectivity and voxel-based functional mapping, a technique that analyzes brain activity using fMRI data.
As Rode explained, brain interactions and the manipulation of these interactions using probiotics is a relatively new research field, emerging over the past 10 years. However, most studies in this area are less than five years old, and fewer than a handful have used fMRI.
“Our study is the first to explore this in an elderly population,” she said.
In a separate presentation, Rode discussed the use of neuroimaging when assessing the psychological effects of probiotics.
She noted that neuroimaging is an objective method for assessing these effects, complementing subjective measures like questionnaires, which ask participants, “How are you feeling today?” or “How have you been feeling for the past four weeks?”
While these questionnaires are crucial for understanding an individual’s experience, neuroimaging appears to be a technique that can detect subtle effects earlier, before they are visible in symptom reports, she explained.
“I believe it’s important to use both of these technologies in tandem,” Rode said. “Moving forward, we should aim to correlate findings from both approaches, rather than treating them separately, and adopt a more integrative methodology.”