Exhaled Methane Is Associated with a Lower Heart Rate.

Area of Science:

• Microbiome research
• Human physiology
• Cardiovascular health

Background:

• Methane (CH4) is produced by human intestinal microbiota and linked to cardiovascular disease.
• CH4 in exhaled breath reflects gut production and may affect the parasympathetic nervous system.
• Previous findings suggest CH4 influences vagal function and heart rate (HR).

Purpose of the Study:

• To investigate the relationship between breath CH4 and resting HR in humans.
• To analyze longitudinal changes in HR and their association with breath CH4 levels over time.

Main Methods:

• Retrospective analysis of 1,126 subjects comparing HR based on detectable vs. undetectable breath CH4.
• Post hoc analysis of a randomized control trial examining HR changes over 14 weeks in relation to CH4 level fluctuations.
• Assessment of the association between the magnitude of CH4 decrease and HR increase over time.

Main Results:

• Subjects with detectable CH4 had significantly lower resting HR (73.0 bpm) than those without (76.0 bpm).
• A decrease in breath CH4 over time was significantly associated with an increase in HR (p=0.0006).
• A greater reduction in CH4 levels correlated with a larger increase in HR (R=-0.31, p=0.03).

Conclusions:

• Gut microbiome-derived methane may play a role in regulating human heart rate.
• These findings suggest a potential novel microbiome-neurocardiac axis.
• Further mechanistic studies are needed to explore this connection.