BMJ Group Aug 12 2025 There seem to be reciprocal links between certain groups of gut bacteria and the risk of insomnia, suggests a Mendelian randomization study, published in the open access journal  General Psychiatry. Certain types of bacteria seem to boost or lower the risk of the sleep disorder while insomnia itself seems to alter the abundance of certain types of bacteria, the findings indicate. Several studies have explored the effects of the gut microbiome on various sleep