A comprehensive overview of the effects of probiotics, prebiotics and synbiotics on the gut-brain axis Original paper
Researched by:
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Divine Aleru
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Divine Aleru
Read MoreI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.
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Divine Aleru
Read More
Researched by:
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Divine Aleru
ID
Divine Aleru
Read More
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Divine Aleru
What was reviewed?
The paper reviewed the effects of probiotics, prebiotics, and synbiotics on the gut-brain axis (GBA), focusing on their potential role in improving mental health and cognitive function. It systematically synthesizes existing clinical and preclinical evidence regarding how these dietary interventions impact the gut microbiota, which in turn influences brain activity. The review examines the mechanisms through which probiotics, prebiotics, and synbiotics modulate the gut-brain communication, such as neurotransmitter regulation, gut barrier integrity, and immune responses, and explores the potential therapeutic applications for conditions like neurodegenerative diseases, anxiety, depression, and cognitive decline.
Who was reviewed?
The review evaluated various clinical and preclinical studies involving probiotics, prebiotics, and synbiotics, with a focus on their impact on the gut-brain axis. The studies reviewed involved different microbial strains, including Lactobacillus, Bifidobacterium, and Saccharomyces, as well as various prebiotic compounds like galacto-oligosaccharides (GOS), fructo-oligosaccharides (FOS), and xylo-oligosaccharides (XOS). The review assessed how these interventions affected the gut microbiota and, consequently, mental health outcomes, such as mood regulation, cognitive function, stress resilience, and neuroinflammation.
What were the most important findings?
The review highlighted several key findings: probiotics, prebiotics, and synbiotics have a significant effect on gut microbiota composition, which can influence brain function via the microbiota-gut-brain axis. Probiotics such as Lactobacillus and Bifidobacterium were found to modulate neurotransmitters like serotonin and GABA, while prebiotics increased short-chain fatty acid (SCFA) production, which in turn supported immune regulation and reduced gut inflammation. Synbiotics, a combination of both probiotics and prebiotics, were shown to provide enhanced benefits, especially in improving cognitive function, emotional regulation, and reducing neuroinflammation. However, the review also acknowledged that while some animal models demonstrated strong effects, clinical evidence in humans remains mixed, with inconsistencies due to strain-specificity, dosage variations, and study designs.
What are the greatest implications of this review?
The greatest implication of this review is that probiotics, prebiotics, and synbiotics could offer a promising non-pharmacological approach to managing neuropsychiatric and neurodegenerative disorders by leveraging the gut-brain axis. The findings suggest that these dietary interventions could serve as adjunct therapies to traditional treatments for conditions like depression, anxiety, and cognitive decline. However, the review emphasizes the need for more rigorous and standardized clinical trials to confirm these effects and optimize the dosages and combinations of probiotics, prebiotics, and synbiotics for targeted therapeutic benefits. Further research into personalized microbiome-based interventions could help develop more effective treatments tailored to individual microbiome profiles.
Probiotics
Probiotics are live microorganisms that offer significant health benefits when administered in adequate amounts. They primarily work by modulating the gut microbiome, supporting a balanced microbial ecosystem. Probiotics have been shown to improve gut health, modulate immune responses, and even influence metabolic and mental health disorders. With growing evidence supporting their therapeutic potential, probiotics are increasingly recognized for their role in treating conditions like irritable bowel syndrome (IBS), antibiotic-associated diarrhea (AAD), and even mental health conditions like depression and anxiety through their impact on the gut-brain axis.
Prebiotics
Prebiotics are non-digestible fibers that selectively promote the growth of beneficial gut bacteria, offering a range of health benefits from improved digestion and immune function to enhanced metabolic health. Prebiotics are an essential part of a healthy diet that supports both gut and overall well-being.
Short-chain Fatty Acids (SCFAs)
Short-chain fatty acids are microbially derived metabolites that regulate epithelial integrity, immune signaling, and microbial ecology. Their production patterns and mechanistic roles provide essential functional markers within microbiome signatures and support the interpretation of MBTIs, MMAs, and systems-level microbial shifts across clinical conditions.