Jet Lag May Cause Obesity by Disrupting Gut Bacteria

It turns out that jet lag may lead to obesity. Scientists have taken a closer look at the circadian clocks that help organisms ranging from bacteria to humans synchronize their biological activities, and have found that disruption of this clock could alter the rhythms and composition of the microbial community in their guts, leading to obesity and metabolic problems.

There are several ways to disrupt the circadian clock in humans, and most of these ways are involved with a modern lifestyle. Shift work or frequent flights across time zones can cause these disruptions, and have been linked to a wide range of diseases, such as obesity, diabetes, cancer and cardiovascular disease. That's why scientists wanted to take a closer look to find out why exactly this is.

In this case, the researchers exposed mice to changing light-dark schedules and abnormal 24-hour feeding habits. After time, the scientists found that the microbial community in the mice lost its rhythmic fluctuations and changed in composition. Not only that, but mice that were fed a high-fat diet gained weight and developed metabolic problems associated with diabetes when they were jet lagged.

"These findings provide an explanation for a long-standing and mysterious observation, namely that people with chronically disturbed day-night cycles due to repetitive jet lag or shift work have a tendency to develop obesity and other metabolic complications," said Eran Elinav, the senior author of the new study, in a news release. "These surprising findings may enable us to devise preventive treatments for these people to lower their risk for these complications."

The findings reveal the importance of taking shift work and jet lag into account when it comes to a person's health. Not only that, but it could reveal a way to help those who do shift work.

"Our findings highlight a new therapeutic target that may be exploited in future studies to normalize the microbiota in those people whose lifestyle involves frequent alterations in sleep patterns, such as shift workers and very frequent fliers," said Elinav. "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."

The findings are published in the journal Cell.