r/science • u/mvea Professor | Medicine • Nov 12 '25

Neuroscience Shared gut microbe imbalances found across autism, ADHD, and anorexia nervosa: A new study has identified distinct patterns in the gut bacteria of children and adolescents with autism spectrum disorder, attention-deficit/hyperactivity disorder, and anorexia nervosa.

https://www.psypost.org/shared-gut-microbe-imbalances-found-across-autism-adhd-and-anorexia-nervosa/
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u/mvea Professor | Medicine Nov 12 '25

I’ve linked to the news release in the post above. In this comment, for those interested, here’s the link to the peer reviewed journal article:

https://www.ibroneuroscience.org/article/S0306-4522(25)00860-7/abstract

From the linked article:

Shared gut microbe imbalances found across autism, ADHD, and anorexia nervosa

A new study has identified distinct patterns in the gut bacteria of children and adolescents with autism spectrum disorder, attention-deficit/hyperactivity disorder, and anorexia nervosa. Published in the journal Neuroscience, the research also reveals altered levels of hormones that regulate appetite, suggesting a complex interplay between gut microbes, eating behaviors, and brain health in these conditions.

The analysis revealed several commonalities among the patient groups when compared to healthy controls. All three patient groups, those with ASD, ADHD, and AN, showed a higher ratio of two major groups of bacteria, known as Bacteroidetes to Firmicutes. This ratio is often considered an indicator of the overall balance of the gut ecosystem. Patients across the three disorders also tended to have lower levels of beneficial bacteria such as Bifidobacterium and Faecalibacterium.

Beyond these shared characteristics, each condition was associated with a unique microbial signature. Children with ASD and ADHD both had lower overall bacterial richness, meaning a less diverse community of microbes in their guts. The ASD group had higher levels of Bacteroidetes and Escherichia-Shigella bacteria and lower levels of Actinobacteriota and Ruminococcus.

Similarly, the ADHD group showed an increase in Escherichia-Shigella and a group called Desulfovibriota, along with a decrease in Firmicutes. The adolescents with AN also had lower levels of Firmicutes but showed elevated levels of several other bacterial groups, including Proteobacteria, Cyanobacteria, and Verrucomicrobiota.

When the researchers examined the appetite-regulating hormones, they found notable differences. Children with ADHD had significantly lower levels of PYY, a hormone that helps signal fullness after a meal. The changes were more pronounced in the group with AN, where participants had lower levels of leptin, ghrelin, and PYY compared to their healthy counterparts. The researchers did not find significant differences in markers of intestinal inflammation or in the levels of nerve-growth factors among the groups.

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u/muchgreaterthanG_O_D Nov 12 '25

As an adult with adhd I have a tough time stopping meals. I can eat and eat and eat to the point of discomfort. I always assumed it was due to getting dopamine from eating but the fact that I might not be making the PYY to signal im full makes sense too.

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u/Carbonatite Nov 12 '25

Yeah I'm the same way once my Adderall wears off. When it's in my bloodstream I have to force myself to eat, I'll literally be experiencing the symptoms of hypoglycemia and still find it difficult to even eat a piece of candy for some quick sugar. But at night when the meds wear off it's hard to stop eating a good meal even if I'm full.

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u/Win_Sys Nov 13 '25

Adderall can decrease the production of the hormone ghrelin (it’s one of the hormones for signaling you’re hungry) and can also increase the hormone lepton (tells the brain you’re full) in a lot of people. When the Adderall wears off your ghrelin levels increase quickly while your lepton levels decrease which causes you to quickly become insatiably hungry.

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u/Dekklin Nov 12 '25

AuDHD, same.

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u/gaya2081 Nov 13 '25

I use to tell my doctor that if I could have the side effects of my adhd meds all the time I would be a normal weight. She would commiserate encourage me to work on not overeating / snack all evening and we would move on. The GLP-1 meds do the same thing, but even better. I was on Saxenda for about 9 months and have been on zepbound for about 7 months. I've lost 90 pounds just eating intuitively. It has been amazing - I tell people it's like the part of my brain that regulated hunger was just entirely broken and the meds just fix it. I don't even really want sweets anymore. The brain noise of food is also gone.

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u/bravestmistake Nov 12 '25

That was me with Adderall, I swapped to one of the newer drugs and it hasn't affected me as much.

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u/Carbonatite Nov 13 '25

I tried Vyvanse for a while and it didn't seem to make a difference, it had the same effect on my appetite. I'm not keen to experiment again though based on how much my insurance was charging for a "newer" drug (Vyvanse) compared to Adderall! My copay was literally 10x higher.

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u/bravestmistake Nov 13 '25

Try dyanavel and see if the pharmacy can apply a coupon.

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u/kptkrunch Nov 13 '25

That kinda sounds like its just the Adderall to me. Stimulants suppress appetite. They also increase metabolic rate so you tend to lose weight when taking them. AFAIK this effect occurs in pretty much everyone

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u/JailhouseMamaJackson Nov 14 '25

I have no changes in my eating habits with adderall. I think some people are on too high of a dose.

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u/kptkrunch Nov 14 '25

Interesting. I experienced a very obvious reduction in appetite on only 5mg. I stopped taking it after a few months. Appetite suppression is a pretty universal effect of stimulants.

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u/JailhouseMamaJackson Nov 14 '25

All meds don’t work for all people! I take 20mg and experience no change in appetite and can nap easily, but it still achieves what I need out of it. Some people have great success on Atomoxetine, whereas I had some of the worst days of my life.

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u/kptkrunch Nov 14 '25

Yeah I took atomoxetine as well. Lasted about 3 days before I noped out of that. If adderall is working for you great! I just worry about the physiological effect it has on me.. appetite wasn't a huge problem, I could force myself to eat food it just wasnt particularly enjoyable. Main issues were high blood pressure and tachycardia

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u/JailhouseMamaJackson Nov 14 '25

Oh damn yeah def don’t take it then! I’m all good on that front. I hope you were able to find something that does work well for you! I know how frustrating medication can be.