Prebiotics are non-digestible dietary compounds, mainly found in fibrous foods such as onions, leeks, artichokes and certain whole grains. These types of fibre cannot be digested by humans but instead act as food for the good bacteria that live in your gut. Prebiotics help gut bacteria produce specific compounds, or metabolites, which have health benefits and support a healthy digestive system.
If you think dietary fibre is just for digestive health, you can think again! New research suggests that prebiotics could help to improve sleep and reduce stress by affecting the metabolites produced by gut bacteria.
Adolescent male rats were fed either a standard diet or a prebiotic-infused diet. A number of physiological measures were recorded before and after stress. Faecal samples were also analysed to investigate the effect of both stress and dietary prebiotics on the gut bacteria and the metabolites they produce.
After stress, rats consuming the standard diet displayed an unhealthy flattening of the body’s natural temperature fluctuations and there was a reduction in the beneficial diversity of the gut microbiome. Rats consuming prebiotics were protected from these effects.
The rats on the prebiotic diet also displayed improved sleep. Notably, after stress they spent more time in a sleep stage which is known to be crucial for recovery from stress. Rats on a prebiotic-infused diet had a very different collection of metabolites than those on the standard diet. They had higher levels of a number of different metabolites which are thought to influence behaviour by gut-brain signalling. Whereas rats on the standard diet had spikes in metabolites which are potentially sleep-disrupting.
The results reveal that prebiotics may improve sleep and buffer against stress by influencing bacteria and the metabolites they produce. Whilst prebiotic foods are healthy, it is uncertain whether consuming prebiotic foods in humans could promote sleep. In this study rats were fed very high amounts of prebiotics, so it is likely that you would have to consume a very large amount to see any benefits.
It is still too soon to say for definite whether consuming prebiotics directly improves sleep. Research is already underway in humans and this learning could ultimately lead to new, natural approaches to treating sleep problems. A very exciting prospect if you still need to count sheep to help you sleep!
Gina is currently a postgraduate student at Imperial College London focussing on microbiome in health & disease. She graduated from Durham University in 2016 after studying Natural Sciences. Following this, Gina worked at Innovate UK for two years helping to drive innovation and business growth in the health & life sciences industry.
Robert S. Thompson, Fernando Vargas, Pieter C. Dorrestein, Maciej Chichlowski, Brian M. Berg, Monika Fleshner. Dietary prebiotics alter novel microbial dependent fecal metabolites that improve sleep. Scientific Reports, 2020; 10 (1) DOI: 10.1038/s41598-020-60679-y