If you have ADHD, you’ve probably heard about the gut-brain connection, but maybe not how deep that connection really goes. Here’s what we know: There are differences in our gut microbiome, some people with ADHD are at a genetic risk for a phenomenon known as intestinal hyperpermeability, the gut-brain axis means our brains have significant impact on our gut microbiome, and this is different for people with ADHD.
But wait, there’s more: We also know there are great reasons to add fermented foods to our diet, but did you know your gut ferments things, too? In that process, your gut creates short-chain fatty acids (SCFAs). While these compounds might be small, their impact on an ADHD brain is anything but.
What are SCFAs?
Gut bacteria create three main SCFAs—acetate, propionate, and butyrate —when fermenting dietary fibers (think vegetables, legumes, whole grains). These small molecules act as chemical messengers between the gut and the brain, influencing everything from inflammation to neurotransmitter production.
Why are SCFAs important for ADHD?
Studies consistently show that people with ADHD have altered levels of SCFAs, which usually indicate increased gut issues and potentially worsened mental health. We also see that people with ADHD have lower levels of specific gut microbes that are key in producing these SCFAs. One 2025 study using this bio-available micronutrient supplement (not an affiliate link) even found that the kids who improved their ADHD symptoms related to emotional dysregulation experienced increases in butyrate-producing bacteria.
The gut-brain axis is the two-way communication system between your gastrointestinal system and your central nervous system. SCFAs help regulate this pathway in several powerful ways:
1. Supporting brain function and focus
Many people with ADHD struggle with things like brain fog, emotional regulation, and executive functioning. SCFAs, especially acetate, can cross into the brain; others like butyrate affect brain function more indirectly. Together, they help regulate inflammation, support neurotransmitter pathways like serotonin and GABA, and influence brain signaling via the gut-brain axis.
Butyrate, in particular, has neuroprotective effects and may help reduce neuroinflammation—a factor linked to anxiety, depression, and even neurodegenerative diseases. It also is connected to increasing the genetic expression of an enzyme called tyrosine hydroxylase, which is necessary for changing protein into dopamine.
2. Calming inflammation
Inflammation affects dopamine signaling, something we know is already out of balance in people with ADHD.
Inflammation also contributes to fatigue, mood swings, and low stress tolerance—all things that tend to hit harder when you have ADHD.
It’s no wonder there’s growing evidence that ADHD is linked to low-grade, chronic inflammation, especially in the gut and brain. SCFAs, especially butyrate, help regulate the immune response and reduce this kind of background inflammation.
3. Influencing your genes (in a good way)
SCFAs can actually change gene expression—specifically the genes related to stress resilience and neural plasticity, aka how well your brain adapts and learns.
Butyrate acts as a histone deacetylase (HDAC) inhibitor, which is a fancy way of saying it helps turn on beneficial genes in your brain and body. Studies found links between butyrate and changing DNA expression related to:
- Improving glucose metabolism and decreasing muscle breakdown
- Reducing cellular oxidative stress (AKA, reducing inflammation)
- Reducing colon and breast cancer
- Protecting dopamine neurons
- Increasing BDNF expression (neuroplasticity)
4. Strengthening the gut barrier
If a healthy gut ingests something bad like a toxin or heavy metal, it will move it through the digestive tract and flush it out (pun intended). If your gut lining is weakened, however, toxins can sneak into your bloodstream and trigger inflammation. This can then affect your brain, your mood, and even how your medications work.
SCFAs reinforce the gut lining and help maintain tight junctions between gut cells, keeping the lining strong. Translation: less inflammation, better nutrient absorption, and more consistent brain energy.
5. Supporting mood, appetite, and energy
SCFAs help regulate the release of hormones like GLP-1 and PYY, which influence:
- Hunger and satiety cues (especially important if you forget to eat or eat past fullness)
- Blood sugar stability (which affects energy, mood, and focus)
- Sleep and circadian rhythm support (vital for ADHD brains)
So What Can You Do?
If you want to support SCFA production, the best thing you can do is feed your gut bacteria what they need to thrive, which means eating a lot of plants and drinking enough water. For some specific ways to support your SCFA production through your diet, check out my article on the 6 Easy Food Strategies to Support Your ADHD Gut Microbiome.
