Sleep loss may be linked to changes in gut bacteria levels

UPPSALA, Sweden, Oct. 25 (UPI) -- A clinical study conducted by Uppsala University researchers suggests limiting sleep may change levels of some bacterial species in the gut.

Changes in the microbiota in the human gut have previously been associated with obesity and type 2 diabetes in addition to chronic sleep loss. Investigators sought to find out whether or not sleep loss affects the gut bacteria.

During the study, the research team analyzed 9 healthy male participants with normal body weight. Their sleep was restricted to 4 hours per night for 2 consecutive days. While scientists note they did not find evidence the diversity of the bacteria was affected by sleep restriction, the experiment did reveal other significant changes. The findings were published in the journal Molecular Metabolism.

"In more specific analyses of groups of bacteria, we did however observe microbiota changes that parallel some of the microbiota changes observed when for instance obese subjects have been compared with normal-weight subjects in other studies, such as an increased ratio of Firmicutes to Bacteroidetes," senior author Jonathan Cedernaes explained in a press release.

The authors went on to note the participants in the study were also 20 percent less sensitive to the effects of the hormone insulin following sleep loss. However, first author Christian Benedict clarified this sensitivity was likely unrelated to the alterations in gut microbiota.

"The gut microbiota is very rich and its functional role far from completely characterized. Future studies will hopefully be able to ascertain how the composition and functional role of the gut microbiota is able to modulate at the individual level how sensitive we humans are to negative metabolic, but also cognitive, effects of sleep loss," Cedernaes added.

Scientists are calling for future studies on the relationship between sleep loss and gut microbiota to involve larger sample sizes and longer intervention periods.