Sleep apnea can do more than just disrupt breathing and sleep quality. Researchers from the University of Missouri School of Medicine and MU Health Care discovered that obstructive sleep apnea (OSA) impacts the gut bacteria of mice. Moreover, transplantation of bacteria from mice with the condition can cause changes in the recipient mouse’s heart.
To conduct the study, the team analyzed a group of mice that received gut bacteria from mice exposed to conditions resembling sleep apnea. They compared cardiovascular outcomes in those mice to a separate group of mice that were not exposed to these conditions. Over a period of six weeks, the team monitored changes in arterial blood pressure and coronary arterial and aortic function. They also analyzed blood to detect and measure a metabolite from the gut that encourages artery hardening.
“We discovered that the mice with transplanted gut bacteria from donors exposed to sleep apnea conditions experienced a blood pressure increase, higher harmful metabolite levels and impairments in aortic and coronary function,” says study co-author Mohammad Badran, PhD, assistant professor at MU’s Child Health Research Institute, in a statement. “In other words, the changes in gut microbiome alone were sufficient to induce some of the changes in cardiovascular function that are characteristically seen in patient with OSA.”
After making this observation, the researchers decided to test whether or not giving the affected mice a probiotic would help ease the damaging effects of the harmful gut bacteria introduced to them. Their results showed that supplementation helped mice that underwent transplantation, but not the donors exposed to OSA conditions.
“These findings indicate probiotics alone are insufficient to protect against the many adverse effects induced by chronic sleep apnea, including inflammation, metabolic dysregulation and antioxidant imbalance, and that probiotics may need to be given in conjunction with the standard treatment of OSA which is CPAP to enhance the probiotic benefit,” says senior author Dr. David Gozal, chair of child health at the MU School of Medicine.
The team concludes that their work not only provides a potential new direction for alleviating cardiovascular symptoms related to sleep apnea, but that it also goes to show that gut bacteria alterations are only a fraction of the issue. To have a greater clinical impact in the future, more studies are needed to determine other factors involved with sleep apnea complications in order to generate the best course of action.
This study is published in the European Respiratory Journal.