A study published in General Psychiatry points to a possible link between gut microbiota and insomnia. The researchers found that certain types of bacteria living in the digestive system may contribute to sleeplessness — and that insomnia itself might influence which bacteria thrive in the gut.
Insomnia is a common problem, with around 10% of adults experiencing it regularly and another 20% reporting occasional symptoms such as difficulty falling asleep, restless nights, and daytime tiredness.
While stress, caffeine, alcohol, and medical conditions are well-known triggers, the new research suggests the gut may also play a role.
Using genetic data from nearly 387,000 people with insomnia and microbiome profiles from almost 27,000 individuals, the researchers identified a two-way relationship.
Fourteen bacterial groups appeared to slightly increase the likelihood of insomnia (by 1–4%), while eight types seemed to lower the risk (by 1–3%).
People with insomnia tended to have reduced levels of seven bacterial groups and higher levels of 12 others.
The gut microbiome — a mix of bacteria, viruses, and fungi — is known to influence digestion, immune function, and the balance of various chemical messengers in the body.
One possible explanation for the connection with sleep is that insomnia may alter the production of neurotransmitters like serotonin and dopamine, which are involved in regulating sleep, and that these changes, in turn, affect the gut’s microbial composition.
The authors stress that these findings are preliminary, but they raise the possibility that microbiome-targeted interventions, such as probiotics, prebiotics, or even faecal microbiota transplantation, could one day become part of insomnia treatment strategies.
