Your Gut Bugs Could Be Keeping You Awake at Night

Gut Bacteria Found to Influence Sleep and Insomnia

Scientists are uncovering surprising evidence that the trillions of microbes living in our intestines may play a major role in how well we sleep. A series of new studies suggest that the composition of the gut microbiome is linked not only to sleep quality but also to the risk of developing insomnia.

Bacteria Connected to Sleepless Nights
In a large genetic study, researchers discovered that certain types of bacteria in the gut were consistently linked with a higher risk of insomnia. Fourteen bacterial groups appeared to make poor sleep more likely, while eight other groups seemed protective, lowering the chance of restless nights.

One particular microbe, Clostridium innocuum, stood out as being strongly associated with sleep problems. Another, Odoribacter, showed a two-way relationship, suggesting that not only can these bacteria influence sleep, but insomnia itself may also change the gut environment in return.

How the Gut Talks to the Brain
Experts believe several biological pathways may explain this connection. Some gut microbes help the body produce key brain chemicals such as serotonin and GABA, both of which are vital for calming the nervous system and preparing the body for rest. Others influence melatonin production — the hormone that tells us when it’s time to sleep.

The gut also shapes the immune system. When harmful bacteria dominate, they may trigger low-level inflammation, which in turn disrupts brain signaling and makes it harder to achieve deep, restorative sleep. This constant cycle of inflammation and poor sleep could help explain why insomnia is so persistent for many people.

The Role of Lifestyle and Modern Living
Diet, stress, late-night screen use, and disrupted body clocks are all thought to influence both gut bacteria and sleep. Processed foods, alcohol, and frequent antibiotic use may reduce healthy microbial diversity, while high-fiber diets and regular exercise seem to support better balance.

Modern life has also introduced new factors — shift work, irregular eating schedules, and chronic stress — all of which may destabilize the microbiome and interfere with natural sleep rhythms.

Digestive Disorders and Sleep Problems Go Hand in Hand
Doctors have long noticed that people with digestive disorders often struggle with sleep. Recent population studies back this up: those with gastrointestinal conditions were nearly twice as likely to experience short sleep, difficulty falling asleep, or waking frequently through the night.

Interestingly, mental health plays a part as well. Depression was found to partly explain the link between digestive issues and poor sleep, highlighting how gut health, brain health, and emotional wellbeing are all interconnected.

What This Means for the Future
While scientists are cautious not to overstate the findings, the evidence points toward the gut as an important player in sleep health. In the future, treatments for insomnia might not only involve sleep hygiene advice or medications, but also targeted approaches to restore a healthier microbiome. This could include diet changes, probiotics, or even microbiome-based therapies.

For now, the message is clear: caring for the gut may be just as important as switching off the lights when it comes to getting a good night’s sleep.