Does the gut microbiome affect mental health? What the studies say
Clinically reviewed by Dr. Chris Mosunic, PhD, RD, MBA
Your gut and brain talk more than you think. We’ll break down the correlation between the gut microbiome and mental health, and share 12 ways to feel more balanced.
That flutter in your stomach before a big meeting. The loss of appetite when you’re stressed. The comfort of a warm meal when you’re feeling low. These moments aren’t just quirks of your body — they’re reminders that the gut and brain are in constant conversation.
Science tells us that this back-and-forth isn’t just metaphorical, but instead shaped in part by the gut microbiome. Aka, the trillions of bacteria and microbes living in your digestive tract.
Research suggests that shifts in the gut microbiome can influence your mood, stress response, and even certain mental health conditions like anxiety and depression. However, the relationship is complex and not as straightforward as a bad gut equating to a bad mood. The brain can also impact the gut, creating a two-way system of signals, chemicals, and feedback loops.
If this sounds confusing, don’t worry. We’ll break down what the gut microbiome is, how it connects to mental health, and some simple ways to support your gut, and by extension, your mind.
What is the gut microbiome?
Simply put, the gut microbiome is the community of bacteria, fungi, and other microbes that live in your digestive tract. These organisms help break down food, produce vitamins, train the immune system, and keep your harmful microbes in check.
In the same way that every person is unique, everyone’s microbiome is also unique. It can be shaped by factors like genetics, diet, environment, stress, and whether you were born through vaginal delivery or C-section.
One important part of your gut microbiome is diversity. The wider the variety of microbes you have, the better digestion, stronger immunity, and greater resilience against illness you tend to have. In other words, the gut microbiome is a dynamic system that touches many areas of your health. It lays the groundwork for how your body communicates and adapts to its environment.
Is there a link between the gut microbiome and mental health?
The link between the gut and your mental health is called the gut-brain axis. And this axis is a two-way communication system that connects your digestive tract and your brain. It’s a network that operates through several pathways, including the vagus nerve, hormones, immune signals, and chemical byproducts produced by microbes.
When your microbiome is balanced, these signals can help regulate your mood, your responses to stress, and your overall stability. But when it’s disrupted, this conversation can shift, which may affect your mental health.
Additionally, stress, trauma, and depression can affect your microbiome and create cycles that affect both your body and mind.
What the studies say
Although much of the science is still emerging, studies generally support the idea that the gut and brain influence each other. Here’s how:
Mood disorders: People with depression and anxiety tend to have less diverse microbiomes than those without these conditions. A 2023 review found consistent differences in certain bacterial groups among individuals with major depressive disorder.
Probiotics and “psychobiotics”: Some trials suggest that probiotics might reduce symptoms of anxiety and mild depression. A meta-analysis of trials submitted up to 2020 concluded that probiotic interventions showed potential in improving depression or anxiety symptoms.
Stress response: Animal studies show that mice raised without microbes have exaggerated stress reactions, which can be reversed when bacteria are introduced. Additionally, smaller human studies have suggested that probiotics can help reduce perceived stress in adults.
Cognitive health: Early research is exploring whether microbial imbalances contribute to conditions like Alzheimer’s and Parkinson’s disease. These findings are still preliminary, but inflammation does appear to be a key link.
How to support your gut (and mind): 12 tips to improve your microbiome naturally
One of the most practical ways to care for your gut and your mind is by eating nourishing foods. But there are other ways to help naturally improve your microbiome as well. Here are some ways you can help your body and brain work more effectively together.
1. Eat more fiber-rich plants
Gut microbes thrive on fiber, especially the kind found in whole foods like beans, oats, leafy greens, berries, and nuts. These fibers feed bacteria and can lower your inflammation.
Try this: Swap white rice for a mix of quinoa and roasted vegetables, or add chickpeas to a salad. Even one extra serving of plants a day can help diversify your microbiome.
💙 Improve your relationship with food by listening to Tamara Levitt’s series Mindful Eating.
2. Include fermented foods
Fermented foods naturally contain live cultures, known as probiotics, that can help increase your microbial diversity. Yogurt, kefir, sauerkraut, kimchi, miso, and kombucha all fall into this category.
Try this: Add a spoonful of kimchi or sauerkraut to your dinner or have a small bowl of yogurt with fruit as a snack.
3. Choose whole foods over ultra-processed ones
Highly processed foods, especially those high in added sugars and artificial additives, are associated with less diverse microbiomes. So, try to limit them in favor of whole foods.
A good rule of thumb is that when you know everything that’s in your meal and on your plate, you’re getting better nutrition. If you can’t pronounce most of the items on an ingredients list, swap it for a whole food or a more natural alternative.
Try this: If you tend to go for soda, try trading it for sparkling water with lemon.
4. Stay hydrated
We’re not making news when we say hydration is key, but it's worth a reminder. Water helps keep digestion moving, which can indirectly help your gut microbiome. And certain microbes thrive in a hydrated environment.
Try this: If plain water feels boring, consider adding slices of cucumber. You could also have herbal teas instead — it all counts toward your hydration.
5. Prioritize sleep
Sleep does more than just make for a rough morning or tough workday. Poor or irregular sleep can also disrupt your microbial balance and affect your mood.
Try this: Try a wind-down routine by dimming the lights, reducing screen time, and doing something calming, like reading or stretching, before bed.
Related read: 10 tips for better sleep: essential habits for a restful night
6. Move your body in ways you enjoy
Moving your body is helpful for so many parts of your overall wellbeing. But beyond the more obvious benefits, getting your blood pumping helps your microbial diversity and lowers stress. Both of which are good for the gut-brain axis.
Try this: Go for a 20-minute walk after lunch, dance to music while cooking, or practice some gentle yoga before bed.
Related read: 7 simple movement exercises to boost your mental health
7. Manage stress with grounding practices
No one likes feeling stressed, but it can also mess with your microbiome, so lowering it can help your gut stay in better health.
Try this: Take a few slow breaths before checking email or step outside for five minutes during your workday. You could also call a friend instead of scrolling when you feel overwhelmed.
Related read: 18 grounding techniques to help relieve anxiety
8. Limit unnecessary antibiotics and medications
Antibiotics can wipe out both harmful and beneficial bacteria, which may deplete your microbiome. Other medications, like long-term proton pump inhibitors, can also affect your gut balance.
Try this: Take antibiotics only when prescribed and necessary. If you need them, pair with a gut-friendly diet of fiber and fermented foods during and after treatment.
💙 Get in touch with your gut during the Gut-Brain Connection session with Mel Mah.
9. Spend time in nature
Getting outside can do more for you than just boost your mood. Exposure to diverse environments like soil, plants, and fresh air can introduce your body to a wider range of microbes. This kind of environmental diversity is linked to healthier microbiomes.
Try this: Garden, walk in a park, or sit on the grass barefoot. If you live in a city, consider getting some indoor plants, as they can also bring microbial variety into your space.
10. Build strong social connections
Turns out that social hang with your besties, or a heart-to-heart with family, may improve your mental and physical wellbeing. Social connection, laughter, and shared meals help support mental health, which could help improve your gut health indirectly.
Try this: Eat with others when you can, or chat with a neighbor as you take out the garbage. Connection in small doses can do wonders for you.
11. Consider probiotics and prebiotics
Probiotics can introduce specific strains of bacteria, while prebiotics, like inulin, feed the bacteria you already have. But their effects vary widely from person to person. If you’re unsure about adding a prebiotic or probiotic supplement to your regimen, consult with your primary care doctor.
Try this: More than anything, focus on whole foods first. Then talk to your healthcare provider if you’re curious about adding supplements.
12. Embrace consistency over perfection
The gut microbiome responds to patterns, and not just one-off choices. So if you decide to get a treat, remind yourself that one donut won’t wreck your microbiome. In general, what matters most is the overall rhythm of your daily habits.
Try this: Choose one or two changes to your lifestyle that feel sustainable, like adding a serving of vegetables at lunch or walking after dinner. Then slowly build from there.
Gut microbiome and mental health FAQs
How does the gut microbiome affect mental health?
The gut microbiome communicates with the brain through the gut-brain axis. This axis is a network that involves nerves, hormones, and immune signals.
Microbes in your gut can produce neurotransmitters, like serotonin and dopamine. These neurotransmitters play big roles in regulating your mood and balancing emotions. They also influence inflammation in your body, which is linked to conditions like depression and anxiety.
When your microbiome is out of balance, these signaling pathways can be disrupted, which can then affect how you feel both mentally and emotionally.
What are the best foods for gut and mental health?
Fiber-rich plants, like beans, lentils, whole grains, fruits, and vegetables, are good because they feed beneficial bacteria. Additionally, fermented foods, like yogurt, kefir, sauerkraut, kimchi, and miso, provide live microbes that can help enrich your gut.
Healthy fats have also been linked to better brain and gut health, especially omega-3s from fish, flaxseeds, and walnuts. But overall, the key is variety. Different foods feed different microbes, and the more diverse your diet, the more balanced your microbiome tends to be.
What is the gut-brain axis?
The gut-brain axis is the two-way communication system between your digestive tract and your brain. It operates through several pathways, like the vagus nerve, immune signaling, and hormone release.
This means that your gut can influence your brain function. And conversely, it means that some mental states, like stress or anxiety, can potentially alter your gut activity.
What are the symptoms of an imbalance in the gut bacteria?
An imbalance in gut bacteria, typically called dysbiosis, can show up in many ways. Digestive symptoms like bloating, irregular bowel movements, gas, and discomfort are common signs.
Some people also notice increased fatigue, skin issues, and greater sensitivity to stress. On top of this, heightened anxiety and low mood can accompany microbial imbalances.
How long does it take to improve gut health naturally?
The gut microbiome can respond to dietary and lifestyle changes surprisingly quickly. Some studies show significant shifts within a few days of changing what you eat. But lasting improvements, like greater microbial diversity and more stable gut function, usually take weeks to months of consistent habits.
In general, small and steady changes in your diet, sleep, movement, and stress management can add up over time and help give you balance in the long run.
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