Gut microbiome health plays a key role in sleep regulation via the gut-brain axis.

noli's read

The concept that the gut and brain communicate is firmly established in scientific literature. Observational studies and animal models have shown that microbiome diversity influences the production of neurotransmitters like serotonin, a precursor to melatonin, which is essential to the circadian cycle (review in 'Nature', 2020). It is proven that certain bacterial metabolites interact with the central nervous system. However, one must avoid exaggeration: while the link is real, direct human research remains emerging. Most solid evidence comes from ongoing clinical studies or correlations, rather than definitive causal evidence in humans. Claiming that the gut is the 'missing key' is an attractive marketing simplification, although the microbiome is likely a contributing factor rather than an isolated silver bullet.

the sources

No named source held this one up — that absence is part of the verdict.