New York,  People with blood pressure issues, read this carefully. Researchers have found associations among disrupted sleep, elevated blood pressure and changes in the gut microbiome.

The gut microbiota or microbiome refers to the collection of microorganisms living in the intestines.

In the study, published in the journal Physiological Genomics, the research team aimed to determine whether a 28-day period of disrupted sleep changed the microbiota in rats.

They also sought to identify biological features associated with undesirable arterial blood pressure changes.

Using rats, the researchers disrupted their sleep periods. Rats are nocturnal, so the experiments were designed to interfere with their daytime sleep periods.

Telemetry transmitters measured the rats' brain activity, blood pressure and heart rate. Faecal matter was also analysed to examine changes in the microbial content.

When rats had an abnormal sleep schedule, an increase in blood pressure developed -- the blood pressure remained elevated even when they could return to normal sleep.

"This suggests that dysfunctional sleep impairs the body for a sustained period," said study author Katherine A Maki, Associate Professor at the University of Illinois in Chicago in the US.

According to the study, undesirable changes were also found in the gut microbiome -- the genetic material of all bacteria living in the colon.

Contrary to her initial hypothesis, Maki found that the gut microbiome changes did not happen immediately, but instead took a week to show unfavourable responses such as an imbalance among different types of bacteria including an increase in microbes associated with inflammation.

"When the sleep disruption stopped, everything did not come back to normal immediately. This research shows a very complex system with the presence of multiple pathological factors," Maki said.

This was initial research, and studies will continue to examine pathways involving the gut microbiome and metabolites produced by gut bacteria.

The researchers will see exactly how sleep characteristics are changed and how long blood pressure and gut microbiome alterations persist. They will then determine how this information translates to humans.

"We hope to find an intervention that can help people who are at risk for cardiovascular disease because of their work and sleep schedules," the study authors wrote.