Is the gut microbiota the key to high-quality sleep?

Butyrate is a substance produced by the fermentation of dietary fiber under the influence of the gut microbiota. According to a new study published in the Scientific Reports journal, it seems to play a major role in sleep onset and sleep quality..

 

Several studies have shown that sleep is highly dependent on the quality of the gut microbiota, with which it is constantly interacting. While a depletion in bacterial flora leads to a decrease in sleep duration, chronic sleep disorders or alterations of the sleep-wake rhythm lead in turn to an imbalance of the microbiota (called “dysbiosis”).

Butyrate: a sleep-promoting agent?

Researchers from the University of Washington aimed at identifying molecules used as sleep-inducing signals. They focused primarily on butyrate, a short-chain fatty acid mainly found in dairy products and fiber from many plants (asparagus, oat flakes, artichokes, raw garlic, leeks, onions). When produced by the intestines under the action of specific bacteria, butyrate enters into the portal vein, a large blood vessel that transports it to the liver, where it is stored. According to the researchers’ hypothesis, it acts on the portal vein’s sensory mechanisms in order to promote sleep.

Increase in deep sleep

Butyrate was thus tested in rodents according to three modes of administration. Subcutaneous injection, which is supposed to act on the entire organism, had no effect. On the contrary, oral administration increased the duration of deep sleep* by around 50%, decreased body temperature, and reduced episodes of paradoxical sleep**. Direct injection into the portal vein had similar, but enhanced, effects, confirming the involvement of the liver in the process.

Eat better to sleep better!

Butyrate seems to trigger sleep by binding to receptors located on the wall of the liver and/or portal vein. Taking care of your gut microbiota by promoting a diet favorable to the production of butyrate could thus improve sleep disorders. It is probably a healthier and more natural solution than sleeping pills!

 

* Sleep phase ensuring optimal recovery of the body

** Also known as REM sleep (Rapid Eye Movement); it is the last phase of a complete sleep cycle and it is when we dream

 

Sources:

Szentirmai E, Millican NS, Massie AR1et al. Butyrate, a metabolite of intestinal bacteria, enhances sleep. Scientific Reports (2019) 9:7035 | https://doi.org/10.1038/s41598-019-43502-1