ADHD and the Microbiome…and a Nutritional Supplement

A small pilot study, done by New Zealand researchers, was just published[i] that has me pretty excited.  (I love studies that involve nutrition!) The research involved 17 children (aged 7 to 12), diagnosed with ADHD.  10 of these were given micronutrients supplements for 10 weeks, while the others were given a placebo.  While the supplement did not lead to any changes in the structure or composition of the gut bacteria, it did lead to an increase in diversity (richness), which did not occur in the placebo group.  Perhaps most importantly though, there was a significant drop in Bifidobacterium.  A decrease in Bifido species is already associated, potentially, with an improvement in symptoms of ADHD (I’ll come back to this in a moment), and the authors of this study suggest that a multi micronutrient supplement may prove to be a completely safe way of downregulating Bifidobacterium, should there be a need.

Back to the association between Bifidobacterium and ADHD symptoms:

In 2017, a paper was published by an international team of researchers on the gut microbiome of children with ADHD.[ii]  They discovered, “… that the relative abundance of several bacterial taxa differed between cases and controls…A nominal increase in the Bifidobacterium genus was observed in ADHD cases.”  They hypothesize about the potential mechanism of action:  how might such an increased load of Bifido bacterium cause the symptoms of ADHD?  They theorize that this gut bacterium affects dopamine synthesis in such a way as to reduce the ability to await “reward,” which “…constitutes one of the hallmarks of ADHD.”  That is, essentially, the metabolic pathways influenced by the excess of Bifido increase the need for instant satisfaction.

In prior research, this New Zealand team of scientists looked at children with ADHD who stayed on the supplement long term – a year.[iii]  Of the 84 children who finished the study, 84% were “…identified as ‘much’ or ‘very much’ improved relative to baseline functioning…”  This is remarkable in that, only 50% of the children who switched to psychiatric meditations and 21% of those who discontinued treatment reported improvements.  In fact, a switch to medications was “…associated with deterioration in mood and anxiety.”  No side effects were reported with the supplement.

Of course, the link to high levels of Bifidobacteria is not yet confirmed.  The lead researcher of this paper states:  “More research is needed with larger groups of people with ADHD, and to understand the potential effect of diet, medications, age, ethnicity and gender on the results that have been reported.”  Still, remembering my philosophy, “If it can’t hurt and it could help, do it” – perhaps a trial of a broad-spectrum supplement is in order?

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[i] Aaron J. Stevens et al. Human gut microbiome changes during a 10 week Randomised Control Trial for micronutrient supplementation in children with attention deficit hyperactivity disorder, Scientific Reports (2019). DOI: 10.1038/s41598-019-46146-3.

[ii] Aarts, E., et. al. Gut microbiome in ADHD and its relation to neural reward anticipation.  PLoS One. 2017:12(9).  doi: 10.1371/journal.pone.0183509

[iii] Darling, KA, Eggleston, MJF, Retallick-Brown, H, Rucklidge, JJ.  Mineral-vitamin treatment associated with remission in attention-deficit/hyperactivity disorder symptoms and related problems: 1-year naturalistic outcomes of a 10-week randomized placebo-controlled trial.