A new review of studies indicates that higher dietary fibre intake could enhance sleep quality by supporting beneficial gut bacteria. Researchers found lower diversity in gut microbiomes among people with sleep disorders, particularly reduced levels of anti-inflammatory bacteria. This points to potential dietary interventions, though more research is needed to confirm causality.
A systematic review published on SSRN has examined the connection between the gut microbiome and sleep quality, drawing from 53 observational studies involving 7,497 people with sleep conditions and 9,165 without. Led by Zhe Wang at Shandong First Medical University in China, the analysis reveals that individuals with sleep disturbances exhibit lower alpha diversity in their gut bacteria overall.
Specifically, those with insomnia, obstructive sleep apnoea, or REM sleep behaviour disorder show decreased abundance of butyrate-producing bacteria like Faecalibacterium, which are anti-inflammatory, alongside increases in pro-inflammatory species such as Collinsella. Butyrate, generated from fermenting dietary fibre, provides energy to colon cells, bolsters the gut barrier, and curbs inflammation—processes that may influence sleep-regulating mechanisms like hormone release and metabolism.
The findings suggest that the microbial profile could help differentiate clinical sleep disorders from milder complaints, enabling more precise treatments. Katherine Maki at the US National Institutes of Health notes that her ongoing research aligns with these results, identifying similar ties between sleep and Faecalibacterium. "Taken together, these converging findings… highlight a plausible microbiome-metabolite pathway linking sleep and host physiology that warrants direct testing in future mechanistic and interventional studies," Maki states.
Elizabeth Holzhausen from Michigan State University emphasises the observational nature of the data, cautioning against assuming causality. She outlines two possibilities: insomnia might reduce fibre consumption, lowering Faecalibacterium levels, or diminished butyrate from these bacteria could impair sleep. Controlled intervention studies are essential to clarify this, she adds.
While direct fibre recommendations for sleep remain premature, experts advise avoiding caffeine and alcohol, steering clear of late-night meals, and considering tart cherry juice. Broader high-quality diets rich in fibre correlate with improved sleep, underscoring the microbiome's role in overall health.
