Which Probiotic Is Best for ADHD? Exploring Gut-Brain Health

October 20, 2025 •

3 min read

Emerging research suggests a link between gut health and ADHD symptoms, with some studies showing altered gut flora in individuals with the condition. This has led many to question which probiotic is best for ADHD as a complementary therapy.

Quick Summary

Scientific research on probiotics for ADHD is still evolving. Studies show certain strains may support aspects like quality of life or reduce specific symptoms, but results are mixed.

Key Points

Promising Strains: Lactobacillus rhamnosus GG and Bifidobacterium bifidum Bf-688 are among the most researched probiotic strains showing potential benefits for ADHD-related symptoms like quality of life, inattention, and hyperactivity.
Complementary, Not a Cure: Probiotics should be viewed as a complementary strategy to existing, evidence-based ADHD treatments, not as a replacement.
Involvement of the Gut-Brain Axis: The potential benefits are rooted in the gut-brain axis, through which probiotics may modulate neurotransmitter production, reduce neuroinflammation, and produce beneficial compounds like short-chain fatty acids.
Strain Specificity is Key: Results are highly dependent on the specific strain used. Look for products that list the full strain name and are backed by relevant clinical research.
Consult a Professional: Always discuss new supplements, including probiotics, with a healthcare provider, especially when managing ADHD and taking prescription medication.
More Research is Needed: While current findings are promising, study sizes are often small and results can be inconsistent, highlighting the need for further, larger-scale clinical trials.

The Gut-Brain Axis and ADHD

Research highlights a significant connection between the gut and the brain, known as the gut-brain axis. Studies suggest individuals with ADHD may have a different gut microbiota composition compared to those without the condition, implying a potential role of gut imbalance (dysbiosis) in symptom presentation. This connection has fueled interest in probiotics as a potential adjunctive strategy for managing ADHD.

Potential Mechanisms of Action

Probiotics may influence ADHD symptoms through the gut-brain axis by:

Neurotransmitter Modulation

Certain gut bacteria can affect the production of neurotransmitters like GABA and dopamine, which are key for attention and mood. For instance, Lactobacillus and Bifidobacterium species can produce GABA, while other bacteria impact dopamine pathways often disrupted in ADHD.

Reducing Neuroinflammation

Inflammation is potentially linked to ADHD. Probiotics may help maintain gut barrier integrity, reduce systemic inflammation, and potentially ease neuroinflammation.

Boosting Short-Chain Fatty Acids (SCFAs)

Beneficial gut bacteria produce SCFAs from fiber, which support brain health. SCFAs can influence brain activity and reduce inflammation. Some probiotic and synbiotic formulations have been shown to increase SCFA production.

Promising Probiotic Strains for ADHD

While not a cure, certain probiotic strains show potential in research:

Lactobacillus rhamnosus GG (LGG)

Studies on LGG for neurodevelopmental conditions are extensive. Early life exposure to LGG was associated with a lower risk of later neuropsychiatric disorders, including ADHD. A pilot trial in children and adolescents with ADHD showed LGG improved health-related quality of life, specifically emotional and social functioning.

Bifidobacterium bifidum Bf-688

Eight weeks of supplementation with this strain in children with ADHD led to improvements in inattention and hyperactivity/impulsivity. It also modified gut microbiota and was linked to some weight gain.

Lactobacillus plantarum PS128

Research in children with both ADHD and Tourette syndrome indicated improvements in ADHD-related symptoms with this strain.

Multi-Strain and Synbiotic Formulations

Some evidence suggests multi-strain probiotics might be more effective than single strains, though results are inconsistent. Synbiotic 2000, a blend of probiotics and prebiotics, has been shown to reduce inflammatory markers in individuals with ADHD.

Comparison of Probiotic Strains for ADHD


Strain	Researched Benefits for ADHD	Study Population	Key Findings
Lactobacillus rhamnosus GG (LGG)	Improved quality of life, reduced risk of neuropsychiatric disorders (early intervention).	Infants, children, adolescents.	Improved emotional and social functioning in children with ADHD; long-term preventive effect when given in infancy.
Bifidobacterium bifidum Bf-688	Improved inattention and hyperactivity/impulsivity symptoms.	Children with ADHD.	Enhanced attention and reduced hyperactivity; beneficial for weight gain in some children.
Lactobacillus plantarum PS128	Reduced ADHD-related symptoms (in those with comorbid Tourette syndrome).	Children with comorbid ADHD/Tourette's.	Improvements in SNAP-IV scores, suggesting benefit for ADHD symptoms in a specific patient group.
Synbiotic 2000 (Multi-Strain)	Reduced inflammation markers, improved emotional regulation in adults.	Children and adults with ADHD.	Decreased markers of intestinal and vascular inflammation; improved emotion regulation in adult participants.

How to Choose a Probiotic for ADHD

Selecting a probiotic requires careful consideration:

Prioritize specific strains: Look for products listing the full strain name and research those linked to ADHD or mental health studies.
Verify viability and CFU count: Ensure the product guarantees CFUs at expiration. Doses are typically 1-10 billion CFUs.
Ensure survival: Choose supplements designed to survive stomach acid.
Seek third-party testing: Reputable brands provide evidence of independent testing.
Look for synbiotic options: Consider formulations combining probiotics with prebiotics.

Important Considerations and Limitations

Probiotics for ADHD are a developing area; they are not a substitute for standard treatments like medication and therapy. While some studies are promising, results can be inconsistent, highlighting the need for more extensive research. Individual responses vary. Always consult a healthcare provider before starting any new supplement, especially for children or those on medication.

Conclusion: The Evolving Role of Probiotics for ADHD

Research on the gut-brain axis is advancing our understanding of ADHD. While findings are preliminary, specific strains like Lactobacillus rhamnosus GG and Bifidobacterium bifidum Bf-688 show potential as complementary approaches to improve symptoms and quality of life. Integrating a high-quality, evidence-backed probiotic with a healthy lifestyle including diet, exercise, and stress management may support brain and gut health. Continued research is essential to clarify the most effective microbial interventions for ADHD.

Here is an informative article on how to choose a probiotic.

Frequently Asked Questions

Research has focused on strains such as Lactobacillus rhamnosus GG, Bifidobacterium bifidum Bf-688, and Lactobacillus plantarum PS128. Some multi-strain formulations, like Synbiotic 2000, have also been investigated for their effects on inflammation related to ADHD.

No, probiotics should not replace prescribed ADHD medication. They are considered a complementary therapy and should be used as part of a comprehensive treatment plan under a healthcare provider's supervision.

The gut and brain are connected via the gut-brain axis. An imbalance in gut bacteria (dysbiosis) may influence the production of neurotransmitters, increase neuroinflammation, and alter other metabolic pathways involved in ADHD symptoms.

The timeline for observing potential effects varies. Many studies showing benefits involved supplementation for at least 8 to 12 weeks, as the gut microbiome takes time to shift and adapt.

Probiotics generally have a good safety profile with minimal side effects for most people. However, starting a new supplement can cause mild digestive upset. Individuals with compromised immune systems should consult a doctor first.

Look for a product that specifies the full strain name (e.g., Bifidobacterium bifidum Bf-688), guarantees the CFU count until the expiration date, and has been third-party tested for potency and purity.

Yes, probiotics are generally safe for children, but it is essential to consult with a pediatrician before starting any new supplement, especially if the child is on medication.

Studies show that probiotics can help reduce markers of both intestinal and systemic inflammation, which is believed to contribute to neuroinflammation linked to ADHD pathology. By lowering inflammation, probiotics may help improve overall brain health.