Based on the data available in Pillser's research database, here's what we know:

Lactobacillus rhamnosus GG and ADHD

Pillser's research database contains 3 studies on Lactobacillus rhamnosus GG and health-related quality of life, and notably, beneficial effects were observed specifically in children with ADHD¹. Here are the key details:

• 2 out of 3 studies reported beneficial effects on health-related quality of life, with effect sizes ranging from small to moderate.
• The third study found a neutral effect (though this was in adults with ulcerative colitis, not children with ADHD).
• The median study duration was 28 days, but effects were noted at longer follow-up (3 months) in one trial.
• Dose information was largely not reported, limiting generalizability.

Limitations

However, there are important caveats:

1. No specific data on "social functioning": The evidence points to improvements in overall health-related quality of life rather than social functioning specifically.
2. Low evidence level: The data is categorized as having "low evidence" with a "small effect" — meaning the findings are preliminary.
3. Mixed results: One high-quality study in the quality-of-life category showed no effect.

Bottom Line

There is some preliminary evidence that Lactobacillus rhamnosus GG may improve health-related quality of life in children with ADHD, but there is not enough specific research to conclude that it improves social functioning in this population. More rigorous studies are needed before firm recommendations can be made.

As always, any decisions about supplement use for a child with ADHD should be discussed with their healthcare provider.

Footnotes

1. Pillser research database, Lactobacillus rhamnosus GG and Improved Health-related Quality of Life. ↩