Two studies presented at the ASM Microbe 2026 conference investigated the role of the bile acid receptor FXR in cardiovascular disease related to sleep apnea, using mouse models. The research was conducted by a team including Celeste Allaband, DVM, Ph.D., from the University of California, San Diego.
Study Method and Models
Two groups of genetically modified mice were used: ApoE knock-out mice, which are prone to heart disease, and ApoE/FXR double knock-out mice, which lack the FXR receptor in addition to being prone to heart disease. Both groups were exposed to either normal air or conditions simulating obstructive sleep apnea (OSA) , which involves repeated interruptions in breathing and intermittent hypoxia and hypercapnia.
Researchers analyzed fecal samples to assess gut microbes and metabolites. At the conclusion of the study, arterial plaques were measured in the mice.
Key Results
Mice lacking the FXR receptor showed significantly reduced fatty plaque buildup in the aorta and aortic arch compared to mice with the receptor. Some plaque remained in the pulmonary artery.
The study suggests that microbially modified bile acids signaling through the FXR receptor are a factor in atherosclerosis under sleep apnea-like conditions.
Background and Context
Bile acids are produced by the liver and released into the intestine, where they are modified by gut microbes. They act as signaling molecules for various receptors, including FXR. Previous work by the same research group indicated that microbially modified bile acids influence the extent of atherosclerosis.
Next Steps
Allaband stated that the team plans to follow up by:
- Cross-referencing their findings with human datasets
- Testing the supplementation of specific bile acids
- Evaluating potential probiotic microbes to prevent or reduce disease