How to Stop Overthinking at Night

The gut—brain connection behind this

The gut and brain talk constantly through the vagus nerve, hormones and immune signals. When the body is in 'alert' mode the gut tenses too, and gut discomfort can feed back into a sense of unease — a loop that slow breathing can interrupt.

More than 90% of the body's serotonin is produced in the gut, which is part of why digestion, mood and sleep are so tightly linked.

Evidence on diet and the microbiome is genuinely promising but still developing; results vary between people, and lifestyle steps work alongside — not instead of — medical care.

References

• Mayer EA. Gut feelings: the emerging biology of gut—brain communication. Nature Reviews Neuroscience. 2011;12(8):453—466.
• Cryan JF, et al. The Microbiota-Gut-Brain Axis. Physiological Reviews. 2019;99(4):1877—2013.
• Yano JM, et al. Indigenous bacteria from the gut microbiota regulate host serotonin biosynthesis. Cell. 2015;161(2):264—276.