Scientists have discovered that jet lag not only confuses the human body's sleeping patterns -- it can also make travelers gain weight.

Researchers from Israel have found a strong circadian rhythm among all the organisms that are in the human gut. This rhythm, however, seemingly becomes disrupted when the person changes the time zone where he is.

The study published in the Cell journal reveals that the microbes in the gut of humans and mice have circadian rhythms that are controlled by the body's biological clock.

When the circadian rhythm is disrupted as the host body changes time zones, the microbes are confused, leading to problems in metabolism and an increased risk to obesity.

Eran Elinav, one of the researchers from the Weizmann Institute of Science, says the results of the study explain the previously mysterious fact that people with unstable day-night cycles, such as frequent travelers suffering from jet lag and employees with shifting schedules, are more at risk in developing obesity and other complications due to problems with their metabolism.

Elinav said that the findings would allow researchers to develop preventive measures for people in these situations, so that they would be less prone to developing complications.

A person's sleeping patterns have been connected to several diseases in addition to obesity, including cancer, diabetes and cardiovascular problems. However, until the findings of the study, it was unclear just how exactly the disruptions in the circadian rhythms were increasing a person's risk for these ailments.

The study experimented on mice, exposing them to varying schedules of light and dark, along with abnormal feeding times spread across 24 hours. The experiment led to a massive confusion of the rhythmic fluctuations of the microbes within the mice. In addition, fatty food being fed to the jet-lagged mice made them gain weight quicker. They also developed problems in metabolism related to diabetes.

Two people who traveled to Israel from the United States also showed changes in the composition of the microbes in their guts. The bacteria linked to metabolic diseases such as obesity grew faster.

"Targeting the harmful changes in the microbiota in these large human populations with probiotic or antimicrobial therapies may reduce or even prevent their risk of developing obesity and its complications," Elinav said.

Elinav shared his fascination over the way gut microbes, living completely in a dark environment, feature a circadian behavior of being sensitive to light and dark.