If you follow mental health conversations in 2025, it can feel like everything comes back to the gut. Probiotics. Inflammation. Serotonin. Microbiomes. The implication is usually subtle but clear: fix your gut and your mental health will follow.

Here’s our position at Modern Therapy Alliance.

Yes, the gut–brain connection is real. Yes, there’s solid medical evidence behind it. And yes, there are very good reasons people are paying more attention to it now. There are also myths, exaggerations, and a growing tendency to turn gut health into a universal explanation for problems that are far more complex. That’s where we slow things down.

Before explaining how we actually work with gut–brain health in therapy, it helps to clarify what the broader conversation is grounded in.

What people are talking about when they talk about gut–brain health

Most gut–brain discussions revolve around a few well-established ideas. One of the most cited is serotonin. The Harvard Medical School notes that roughly 90% of the body’s serotonin is produced in the gut, not the brain, and the National Institutes of Health has published research showing how gut microbiota influence stress response, mood, and cognition.
https://www.health.harvard.edu/diseases-and-conditions/the-gut-brain-connection
https://www.nih.gov/news-events/nih-research-matters/gut-brain-connection

Another major focus is inflammation. Chronic inflammation has been linked to depression, anxiety, fatigue, and cognitive fog, with repeated studies published in The Lancet Psychiatry. Nutrition has also moved firmly into mainstream mental health research. The World Health Organization acknowledges growing evidence that diet affects mental health outcomes, and research summarized in Nature links ultra-processed diets to increased depression risk.
https://www.thelancet.com/journals/lanpsy
https://www.who.int/publications/i/item/WHO-HEP-HPR-2022.1
https://www.nature.com

None of this is fringe science. What is new is how often these ideas are presented as complete explanations instead of partial ones.

How we actually work with gut–brain health at Modern Therapy Alliance

We don’t treat gut–brain health as a trend. We treat it as a set of basic physiological principles that are too often ignored in therapy and medication conversations.

SSRIs, serotonin, and the gut: a real coordination gap

If you’re taking an SSRI and no one has ever talked with you about your gut health, digestion, or possible inflammatory issues, that’s a problem. SSRIs are Selective Serotonin Reuptake Inhibitors. Serotonin is literally in the name. And most of it is produced in the gut.

What continues to surprise us is how many people come in on antidepressants without ever being told this. If the psychiatrist prescribing your medication isn’t asking about digestion, chronic GI issues, or inflammation, there’s a real gap. And if a gastroenterologist is treating digestive symptoms without knowing someone is struggling with depression, that’s another gap.

Those systems are connected, and those clinicians should be communicating. Often, they aren’t.

We don’t manage medication and we don’t diagnose GI conditions, but we do expect people to understand how their system works and to advocate for coordinated care. This lack of integration is one of the most common blind spots we see.

What serotonin actually does—and what it doesn’t

Another major source of confusion is treating serotonin as a universal “feel-good” chemical. It isn’t.

Serotonin is primarily associated with mood stability, emotional steadiness, and a sense of hopefulness. Dopamine is more closely tied to motivation and reward. Endorphins relate to pleasure and pain relief. Oxytocin is about bonding and social connection.

Supporting serotonin regulation through gut health may help reduce despair or emotional volatility. It will not suddenly make you more productive at work, more ambitious, or more socially confident. When people claim gut health will fix everything, they collapse very different biological systems into one story. Understanding what serotonin actually affects, and what it doesn’t, matters.

Anxiety, sleep, and digestion: start where it actually helps

A lot of clients come in wanting to spend session one telling us every thought they had while staring at the ceiling at 2:00 a.m. We’re not against that. We’re just more interested in getting you asleep before the ceiling becomes your therapist. So we ask a more practical question: why are you awake for three or four hours after you go to bed? Because if we can help you fall asleep sooner, you’ll spend a lot less time rehearsing the same worries in the dark like it’s a nightly routine.

One of the strongest drivers of anxiety is sleep quality. If you’re struggling with anxiety and not taking sleep seriously, insight alone isn’t going to compensate. We see the same pattern repeatedly: people are anxious, wired, and exhausted while eating heavy or spicy meals late at night. Their digestive system stays active when their nervous system should be powering down. Sleep quality drops, and anxiety escalates.

This isn’t speculative. The Cleveland Clinic and the National Sleep Foundation both document how digestion and circadian rhythm disruption affect sleep and stress hormones.
https://health.clevelandclinic.org/gut-brain-connection
https://www.thensf.org

At Modern Therapy Alliance, one of the simplest early interventions we use is helping people take sleep seriously. That often means stopping spicy or heavy food at night and actually measuring sleep quality instead of guessing. We prefer practical tools people already own, like an Apple Watch, because feedback beats speculation every time.

If sleep doesn’t improve, anxiety work stalls. There’s no clever workaround for that.

Protein, blood sugar, and brain function: old science, not a fad

The relationship between protein intake, blood sugar stability, and brain function isn’t new. It’s been discussed in medical and psychological literature for well over a century. Early ADHD treatment models emphasized higher protein intake and stabilized blood sugar long before modern stimulant medications existed. The logic was straightforward: the brain needs consistent fuel to regulate attention, mood, and impulse control.

The American Psychiatric Association continues to acknowledge nutrition as a relevant factor in mental health care. Protein matters. Blood sugar crashes matter. That doesn’t mean food causes mental illness. It means ignoring basic physiology creates unnecessary suffering.

Where we draw clear boundaries

We are not trying to turn therapists into medical doctors or nutritionists. That’s not our role, and it shouldn’t be.

What we are saying is that therapy breaks down when clinicians ignore basic physiology, and it becomes irresponsible when every issue gets reduced to food or gut health alone. This is where differential diagnosis matters. Some symptoms are driven largely by sleep and physiology. Some are psychological. Most are a mix.

Changing what you eat will not fix complex mental health issues by itself. But therapy that ignores how sleep, digestion, and the nervous system affect mood and regulation is incomplete.

Understand the system. Don’t oversimplify it. Don’t pretend one lever fixes everything.

What gut–brain research actually changes

Gut–brain research doesn’t replace therapy. It deepens it. It reminds us that mental health doesn’t live only in thoughts or memories. It lives in bodies that need fuel, rest, and regulation.

At Modern Therapy Alliance, we work with you as a whole system. We don’t reduce your struggles to food, and we don’t ignore your body either. That balance is the work.

Opening the conversation

We believe the gut–brain connection is real.
We also believe the hype around it often goes too far.

Where do you land?
Have changes in sleep or diet helped your mental health more than talking alone?
Or have you been frustrated by advice that reduced everything to food?

Agreement and disagreement are both welcome. That’s how better therapy gets built.