The bacteria in your gut do far more than help digest food. In recent years, scientists have discovered that they play an important role in myriad bodily processes, from mood and mental health to obesity and gastrointestinal disease. According to recent research, the trillions of microbes in your gut could also impact how you sleep, The Guardian reports.

Though investigation into the links between sleep and intestinal bacteria is just beginning, scientists already know that lack of sleep takes a toll on the body beyond just causing fatigue. It may contribute to the risk of obesity and developing type 2 diabetes. However, digestive processes may themselves affect sleep, scientists now suggest. "There is no question in my mind that gut health is linked to sleep health, although we do not have the studies to prove it yet," psychologist Michael Breus told The Guardian.

A study in Frontiers in Behavioral Neuroscience found that rats fed a prebiotic diet (consisting of fiber that gut bacteria can feed on) had better-quality sleep than rats fed a control diet. The researchers linked this better sleep to increases in the gut bacteria Lactobacillus rhamnosus, a popular probiotic strain. The rats spent more time in REM sleep even when they were subjected to stress, which has been linked to insomnia issues.

To demonstrate how the microbiome affects sleep, though, researchers will likely have to untangle it from the many other ways that the microbiome affects our health, mental and otherwise. Imbalances in gut bacteria might influence depression, which in turn disrupts sleep. Other studies have suggested that poor-quality sleep affects the microbiome, rather than the other way around. Given how much impact the microbiome has on our health, it makes sense that there could be links between major health issues like insomnia and our bacterial colonies. The nature of those links, though, will require much more research to tease out.

[h/t The Guardian]