What the Heck Does Sleep Have to Do with My Gut?

Research exploring the role of the gut microbiome has exploded over the past decade. So, what exactly is the gut microbiome? The human microbiota consists of trillions of organisms (bacteria, viruses, fungi) that live supportively with each person primarily residing in the gut. These microbes play an important role in most of our physiological functions, having an impact on both health and disease. They contribute to metabolic functions, protect against invaders, and educate the immune system.  As one could imagine, this is an interesting and promising area of research for a gastroenterologist. Of specific interest is the role the gut microbiota has related to metabolism and energy balance as well as the role that sleep and circadian rhythm play impacting these microbes.  

Chronic sleep fragmentation (many brief arousals throughout the night that the sleeper can recall) occurs commonly and markedly alters eating behaviors which ultimately promote obesity and insulin resistance. As insulin resistance will be a recurring theme throughout these studies, we should discuss what it is. Insulin is a hormone produced by the pancreas that helps unlock the body’s cells so glucose from food we eat can be used as energy. It may be easier to think of insulin as the key that unlocks the door to the cell to use glucose as energy. With insulin resistance, the lock is sticky and the key (insulin) can’t open the door. This in turn leads to a cascade of events that contribute to metabolic disease and weight gain. 

In one study, it was found that four weeks of fragmented sleep in laboratory mice lead to increased visceral fat mass (fat that surrounds organs), inflammation of this tissue, and other markers of negative changes in metabolism like increased insulin resistance. Of note, it is hypothesized that the inflammation of fat cells may be the result of the transfer of microbially-produced substances across the gut lining. Despite these significant inflammatory and metabolic changes, resolving sleep fragmentation reversed these effects. In another study, this time conducted with human subjects, partial sleep deprivation produced similar findings. After just two days of restricted vs. normal sleep, participants exhibited almost 40% greater increased insulin resistance.  

What is happening specifically within the gut microbiota that leads to these changes? In the human study referenced above, the researchers found increased Firmicutes:Bacteroidetes bacteria ratio; don’t overwhelm yourself with the names of these bacteria. What is important to understand is that an increased ratio of these bacteria can produce greater calorie extraction from the diet and this may explain the mechanism through which chronic sleep loss can increase weight gain. Despite one’s efforts to eat a healthy, well balanced diet following fragmented sleep or shortened sleep, they can’t overcome the changes being driven by this robust microbiome community.  

For ways to improve sleep quantity and quality, please come in to the office for a more detailed evaluation. We can also help look at other factors that can impact weight management and help you try to achieve your wellness goals. Call for an appointment at 224.407.4400 or visit our website at www.compgihealth.com.