The Headline Going Around
A widely shared article claims a new study links autism, anorexia, and ADHD through the gut microbiome, and that it "opens the way to future targeted treatments." The underlying research is real and genuinely interesting - grouping anorexia with autism and ADHD in a microbiome study is unusual and worth attention. But the treatment claim goes well beyond what the study itself says.
The Real Study
Researchers at Comenius University in Bratislava (Soltysova et al., published in Neuroscience, 2025) compared gut microbiota and blood hormone levels across 117 children and adolescents: 30 boys with autism spectrum disorder, 14 with ADHD, 21 girls with anorexia nervosa, and 52 matched controls without any of these conditions.
What They Actually Found
All three conditions - autism, ADHD, and anorexia - showed a similar pattern compared to controls: a higher ratio of Bacteroidetes to Firmicutes bacteria, and depletion of beneficial genera like Bifidobacterium and Faecalibacterium. Desulfovibrio bacteria were specifically elevated in both the ADHD and anorexia groups. The researchers also found links to appetite-regulating hormones: lower PYY (a satiety hormone) in the ADHD group, and lower PYY, leptin, and ghrelin in the anorexia group - tying gut bacteria changes to appetite-hormone signaling, not just brain neurotransmitters.
What's Genuinely New Here
Most gut-microbiome research on neurodevelopmental conditions treats autism and ADHD as their own cluster, separate from eating disorders. Grouping anorexia nervosa alongside them - and finding the three conditions look more similar to each other than to healthy controls - is a genuinely novel angle. It connects to something clinicians already see: ADHD and autism both carry meaningfully elevated rates of disordered eating and eating disorders compared to the general population, and this study offers one possible biological thread linking them.
Where the Study Is Honest About Its Own Limits
The sample sizes are small - just 14 to 30 children per condition group - and the researchers themselves flag this as a limitation, along with data collection constrained by COVID-era conditions. Critically, the study did not control for diet, physical activity level, or medication use - all major, well-known influences on gut microbiome composition that could plausibly explain some of the differences seen, independent of the diagnosis itself. This is a cross-sectional, purely observational study: it shows an association at one point in time, not a demonstrated cause. The researchers' own language is notably careful - they describe a "conceivable influence" of gut microbiota on behavior, not a proven one.
The "Opens the Way to Targeted Treatments" Claim Doesn't Hold Up
This is where the honest version diverges sharply from the viral one. The study tested no treatment. No probiotic, dietary, or microbiome-targeted intervention was given to anyone in this research - it is purely descriptive. Any claim that this "opens the way to targeted treatments" is a leap the paper itself does not make; it is describing a correlation worth investigating further, not a validated treatment pathway.
Why This Might Still Matter
Even stripped of the overstated treatment framing, this remains a useful data point. The genuine, clinically-recognized overlap between ADHD, autism, and disordered eating deserves more biological explanation than it currently has, and a shared gut-bacteria signature is a plausible thread worth following with larger, controlled, longitudinal studies - ideally ones that also test an actual intervention.
The Bigger Picture
This connects to the gut-brain axis research we've covered before: neurodevelopmental and psychiatric conditions increasingly show overlapping biological signatures rather than clean, separate mechanisms. That's a genuinely useful direction for research - it just isn't, on its own, a treatment yet.
Sources: Soltysova M, Tomova A, Paulinyova M, Lakatosova S, Trebaticka J, Ostatnikova D. "Gut microbiota in children and adolescents with autism, ADHD and anorexia nervosa, and its link to the levels of satiety hormones," Neuroscience, 2025;585:394-407.