Summary: A new study reports sleep loss can lead to alterations in gut bacteria that have previousle been linked to diabetes and obesity in humans.
Source: Uppsala University.
Results from a new clinical study conducted at Uppsala University suggest that curtailing sleep alters the abundance of bacterial gut species that have previously been linked to compromised human metabolic health. The new article is published in the journal Molecular Metabolism.
Changes in the composition and diversity of the gut microbiota have been associated with diseases such as obesity and type-2 diabetes in humans. These diseases have also been linked with chronic sleep loss. However, it is not known whether sleep loss alters the gut microbiota in humans. With this in mind, Christian Benedict, associate professor of neuroscience, and Jonathan Cedernaes, M.D., Ph.D, both from Uppsala University, collaborated with researchers from the German Institute of Human Nutrition Potsdam-Rehbruecke. In their study, the researchers sought to investigate in nine healthy normal-weight male participants whether restricting sleep to about four hours per night for two consecutive days as compared with conditions of normal sleep (about 8 hours of sleep opportunity) may alter the gut microbiota in humans.
“Overall we did not find evidence that suggests that the diversity of the gut microbiota was altered by sleep restriction. This was somewhat expected given the short-term nature of the intervention and the relatively small sample size. 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. Longer and larger clinical sleep interventions will be needed to investigate to what extent alterations of the gut microbiota may mediate negative health consequences attributed to sleep loss, such as weight gain and insulin resistance,” says senior author Jonathan Cedernaes.
“We also found that participants were over 20 percent less sensitive to the effects of the hormone insulin following sleep loss. Insulin is a pancreatic hormone needed to bring down blood glucose levels. This decreased insulin sensitivity was however unrelated to alterations in gut microbiota following sleep loss. This suggests that changes in microbiota may not, at least in the short-term, represent a central mechanism through which one or several nights of curtailed sleep reduce insulin sensitivity in humans,” says first author Christian Benedict.
“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,” concludes senior author Jonathan Cedernaes.
Source: Jonathan Cedernaes – Uppsala University
Image Source: NeuroscienceNews.com image is for illustrative purposes only.
Original Research: Abstract for “Gut Microbiota and Glucometabolic Alterations in Response to Recurrent Partial Sleep Deprivation in Normal-weight Young Individuals” by Christian Benedict, Heike Vogel, Wenke Jonas, Anni Woting, Michael Blaut, Annette Schürmann, and Jonathan Cedernaes in Molecular Metabolism. Published online October 24 2016 doi:10.1016/j.molmet.2016.10.003
Gut Microbiota and Glucometabolic Alterations in Response to Recurrent Partial Sleep Deprivation in Normal-weight Young Individuals
Changes to the microbial community in the human gut have been proposed to promote metabolic disturbances that also occur after short periods of sleep loss (including insulin resistance). However, whether sleep loss affects the gut microbiota remains unknown.
In a randomized within-subject crossover study utilizing a standardized in-lab protocol (with fixed meal times and exercise schedules), we studied nine normal-weight men at two occasions: after two nights of partial sleep deprivation (PSD; sleep opportunity 02:45-07:00h), and after two nights of normal sleep (NS; sleep opportunity 22:30-07:00h). Fecal samples were collected within 24 hours before, and after two in-lab nights, of either NS or PSD. In addition, participants underwent an oral glucose tolerance test following each sleep intervention.
Microbiota composition analysis (V4 16S rRNA gene sequencing) revealed that after two days of PSD vs. after two days of NS, individuals exhibited an increased Firmicutes:Bacteroidetes ratio and of the families Coriobacteriaceae and Erysipelotrichaceae, with decreases in Tenericutes (all P<0.05) – previously all associated with metabolic perturbations in animal or human models. However, no PSD vs. NS effect on beta diversity or on fecal short-chain fatty acid concentrations was found. Fasting and postprandial insulin sensitivity decreased after PSD (all P<0.05).
Our findings demonstrate that short-term sleep loss induces subtle effects on human microbiota. To what extent changes to the microbial community contribute to metabolic consequences of sleep loss warrants further investigations in larger and more prolonged sleep studies, to also assess how sleep loss impacts the microbiota in individuals who already are metabolically compromised.
“Gut Microbiota and Glucometabolic Alterations in Response to Recurrent Partial Sleep Deprivation in Normal-weight Young Individuals” by Christian Benedict, Heike Vogel, Wenke Jonas, Anni Woting, Michael Blaut, Annette Schürmann, and Jonathan Cedernaes in Molecular Metabolism. Published online October 24 2016 doi:10.1016/j.molmet.2016.10.003