Is Kefir Darm useful for Schlaf?

Whether kefir ('kefir gut') is useful for sleep cannot be answered with strong evidence. Kefir is a fermented dairy product containing probiotics and yeasts. Some animal and small human studies suggest that probiotics can influence sleep via the gut–brain axis, for example by modulating GABA or serotonin. Kefir also contains tryptophan, a melatonin precursor. However, specific research on kefir and sleep is scarce; most studies use generic probiotic blends. Effects are small and vary individually. No clinical trial has shown that kefir reliably improves sleep in people with insomnia or poor sleep. For those who tolerate dairy and have no histamine sensitivity, kefir can be part of a healthy diet, but it is not a proven sleep aid. Caveat: in lactose-intolerant or histamine-sensitive individuals, kefir might even disrupt sleep. Overall evidence is mechanistic – plausible pathways exist, but human data are insufficient. Treat it as a low-risk dietary experiment, not a therapy.