Compounds in prebiotics help restore deep sleep known as non-REM (rapid eye movement) and REM sleep, which reduces stress.
The foods feed the bugs in our gut that communicate with the brain and influence the quality of sleep, say researchers from the University of Colorado at Boulder.
They used mass spectrometry technology to witness the gut-brain signals known as metabolites, bioactive small molecules that are produced by bacteria as food is broken down, in a group of laboratory rats.
The rats were fed either a standard diet or a prebiotic-rich diet, which included compounds in foods such as lentils and cabbage, dairy and kimchi, the Japanese dish of fermented vegetables.
The prebiotic-fed rats had a different metabiome, or metabolite make-up, and had deeper, and better, sleep patterns. By comparison, the rats fed a standard diet were producing metabolites that could interfere with a good night's sleep.
The researchers warn that a bad sleeper might have to eat an enormous amount of sauerkraut or lentils to see an improvement, and prebiotic supplements could work better, depending on a person's individual profile.