Boost Melatonin Naturally: How Gut Health Supports Your Sleep

Ever have trouble sleeping? We usually chalk it up to stress, late-night screen time, or maybe that caffeinated soda at dinner. But your gut may also play a role.

Your body has all kinds of surprising connections, and one of them is between melatonin and your digestive system. Researchers are still figuring out exactly how big a part the gut plays, but it’s clear that it makes its own melatonin, and the gut microbiome may have something to do with it.

Let’s take a closer look at what science knows (and doesn’t yet know) about the gut–melatonin connection.

Melatonin: more than just the sleep hormone

You've probably heard of melatonin as the hormone that makes you sleepy. It's produced by a tiny, pinecone-shaped gland in your brain called the pineal gland. When it gets dark outside, your brain gets the signal to release melatonin, which tells your body it's time to wind down for bed. This helps run your internal 24-hour clock, or circadian rhythm [1].

But melatonin is like a superhero with different powers. It's not just about sleep. It also helps:

Boost immunity

Melatonin helps keep your immune system balanced and ready to defend you. It supports the activity of immune cells, making it easier for your body to fight off unfriendly microbes, infections, and even reduce inflammation [2].

Protect your cells from damage

Melatonin is one of the body’s strongest natural antioxidants. It helps neutralize free radicals that can damage your cells, protecting your DNA and slowing down the aging process [3].

Support your bone health 

Melatonin also plays a role in keeping your bones strong. It influences bone-building cells and may help prevent bone loss over time, which is especially important for protecting against osteoporosis as you age [4], [5].

Your gut makes melatonin, too

It’s not just your brain that’s in the melatonin business—your gut has its own supply line. The tricky part is, we don’t actually know how much it makes. You may have heard claims that the gut pumps out 400 times more melatonin than the pineal gland, but this came from an outdated rat study with methodological flaws [6]. In humans, the best clue we have is that gut melatonin levels look about 10 times higher than those in the blood [7].

The gut and the brain make melatonin separately. In pigs, even when the brain’s pineal gland was taken out of the equation, the gut kept on producing melatonin as usual [8]. Some of this gut-made melatonin can slip into your bloodstream [9], but we don’t yet know how big a contribution it makes to your body’s overall supply.

So rather than thinking of your gut as a “melatonin factory,” it may be more accurate to picture it as an additional source of melatonin—one that works on its own schedule and may play a local role in digestion and gut function, with possible effects on the rest of the body.

How your gut bacteria influence the production of melatonin

So, where do your gut microbes fit into this picture? Turns out they're the managers of the gut's melatonin production.

1. They provide the building blocks for melatonin

Just like you can’t build a Lego castle without bricks, your gut can’t make melatonin without its main building block: serotonin (often called the “happy chemical”). In fact, about 90% of the body’s serotonin is produced in the gut. And here’s where microbes step in—many gut bacteria help shape the pathways that produce serotonin. By influencing these factors, your microbiome may also shape how much melatonin your gut can generate.

2. They crank up melatonin production

Your gut microbes don't just supply the parts; they act like cheerleaders, telling your gut cells to make more melatonin.

• Sending signals: One study in mice found that without gut microbes, the body's melatonin levels dropped. But when good bacteria like Lactobacillus reuteri were added back, they sent a specific signal that told gut cells to start making melatonin [10].
• Making special "foods": Bacteria like Roseburia hominis eat the fiber from your food and produce short-chain fatty acids (SCFAs). These SCFAs signal gut cells to boost serotonin production and to convert more of it into melatonin [11].

A two-way conversation

This isn't a one-sided relationship. Studies done in laboratory settings and animal models supplemented with melatonin show that this hormone “talks” back to your gut microbiome.

Some effects include:

• Melatonin promotes the growth of beneficial microbes like Lactobacillus, Akkermansia, Bifidobacterium, and Faecalibacterium [12], [13].
• The gut microbiome has its own daily rhythmic cycle, which is influenced by the host's light-dark cycle and melatonin levels. Melatonin helps synchronize these microbial rhythms, which can be disrupted by lack of sleep and stress [14], [15]. Melatonin rhythms also shift with the seasons—long summer days can lower melatonin, while shorter winter days boost it.

6 tips to support your gut and brain’s melatonin production

Ready to help your body make more melatonin for a great night's sleep? It all starts with taking care of your gut microbiome and building smart habits. Here’s how:

1. Feed your microbe friends fiber. When gut bacteria digest fiber, they create SCFAs that ramp up melatonin production. Load up on fiber-rich foods like apples, bananas, broccoli, beans, lentils, and whole grains like oatmeal.
2. Eat probiotic-packed foods. Help build a strong and diverse microbiome by eating foods that contain live, helpful bacteria (probiotics). A happier gut is better at managing melatonin. Try adding fermented foods like yogurt, kefir, kimchi, or sauerkraut to your diet.
3. Get your tryptophan. Your body can’t make this essential amino acid on its own—it has to come from the foods you eat. Think of tryptophan as the essential building block your body uses to make serotonin, which then converts into melatonin. Eat foods rich in tryptophan, such as turkey, chicken, nuts, seeds, oats, and bananas.
4. Dim the lights and ditch the screens. The blue light from phones, tablets, and TVs is a major melatonin blocker [16], [17]. It tricks your brain into thinking it's still daytime, shutting down melatonin release. Put all screens away at least one hour before bed. Dim the lights in your house to signal to your body that it's time to wind down.
5. Soak up some morning sun. Getting bright sunlight first thing in the morning helps set your circadian rhythm. This makes the "off" switch for melatonin very clear during the day, which helps your body turn it back "on" at the right time at night [18]. Open your curtains as soon as you wake up or spend 10-15 minutes outside in the morning sunlight.
6. Understand your serotonin and melatonin production capacity: Our gut health test results include the metrics “Serotonin & melatonin in the gut”. It shows the presence of specific bacteria (such as Akkermansia and Faecalibacterium) and important metabolites (such as butyrate, acetate, and propionate), which research suggests may support serotonin and melatonin production in the gut. If you’ve taken a gut health test, you can find these insights in the Results portal under “Metrics related to conditions”. 

Better sleep starts in the gut   

This amazing connection shows that a healthy gut does more than just aid digestion. A balanced, diverse microbiome helps your body make the melatonin it needs, potentially helping you get a restful night's sleep. In turn, a good sleep cycle supports a healthy gut. It’s a perfect example of how everything in your body is connected. So next time you think about your health, don’t forget the tiny but mighty helpers in your gut. Supporting them with fiber-rich, nutritious foods benefits not just your digestion, but also your sleep, mood, and overall well-being.

A Gut Health Test can help you identify imbalances that may be affecting your sleep quality, providing insights to improve your gut health and nighttime rest.