ADHD and the Gut Microbiome Connection

Plain-language summary

Research suggests there might be a link between the gut microbiome and ADHD, and while some studies explore probiotics as a potential support for managing symptoms, the evidence is still emerging and mixed. More research, especially well-designed human trials, is needed to understand this connection fully and determine if probiotics are truly beneficial.

Key findings

• Some studies indicate differences in the gut microbiome in individuals with ADHD, though the exact nature of these differences can vary.
• Probiotics are being investigated as a possible way to help manage ADHD symptoms, with some research suggesting they might have a positive impact. However, some studies also found no significant effect.
• More research is underway to explore how specific probiotic strains or fermented foods like kefir might influence ADHD symptoms and the gut microbiome in both children and adults.
• The quality and reliability of evidence regarding the impact of probiotics on ADHD symptoms vary, with some systematic reviews highlighting the need for more rigorous studies.
• The connection between the gut and brain is complex, and while fascinating, it's important to remember that this area of research is still developing.

Studies cited (5)

1. The gut-microbiome in adult Attention-deficit/hyperactivity disorder - A Meta-analysis — Jakobi B, Vlaming P, Mulder D (2024, European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, meta-analysis)

   DOI: 10.1016/j.euroneuro.2024.07.004

2. A systematic review of microbiome changes and impact of probiotic supplementation in children and adolescents with neuropsychiatric disorders — Ligezka AN, Sonmez AI, Corral-Frias MP (2021, Progress in neuro-psychopharmacology & biological psychiatry, systematic-review)

   DOI: 10.1016/j.pnpbp.2020.110187 PMCID: PMC8138744

3. Exploring the impact of probiotics on adult ADHD management through a double-blind RCT — Miri Levy Schwartz, F. Magzal, I. Yehuda (2024, Scientific Reports, rct)

   Attention deficit hyperactivity disorder (ADHD) is a common neuropsychiatric condition often persisting into adulthood, characterized by inattention, impulsivity, and hyperactivity. Emerging research suggests a connection between ADHD and gut microbiota, highlighting probiotics as potential therapeutic agents. This study involved a double-blind, randomized controlled trial where college students with ADHD received either a multi-strain probiotic supplement or a placebo daily for three months. ADHD symptoms were evaluated using a computerized performance test (MOXO) and the MATAL questionnaire.

4. Gut microbiome differences in children with Attention Deficit Hyperactivity Disorder and Autism Spectrum Disorder and effects of probiotic supplementation: A randomized controlled trial — Novau-Ferré N, Papandreou C, Rojo-Marticella M (2025, Research in developmental disabilities, rct)

   DOI: 10.1016/j.ridd.2025.105003

5. Randomised controlled trial of the effects of kefir on behaviour, sleep and the microbiome in children with ADHD: a study protocol — Lawrence K, Fibert P, Hobbs J (2023, BMJ open, rct)

   DOI: 10.1136/bmjopen-2022-071063 PMCID: PMC10711914