The researchers involved in the study decided to investigate the link because they knew some of the benefits associated with Lactobacillus reuteri rely on oxytocin to work, so they figured there was a chance it was being produced nearby to where the bacteria lives.

They tested this theory by examining the intestinal cells of a variety of species, including humans, under a microscope. Once they’d identified that oxytocin genes were being expressed in this tissue, they moved on to human intestinal tissue – where they were able to identify the presence of oxytocin itself. Fascinatingly, they also found that Lactobacillus reuteri plays a role in controlling this release.

This is exciting for a few reasons, not least because of the mental health benefits associated with having good levels of oxytocin. While the hormone’s main function in women is to facilitate childbirth – it stimulates the muscles of the uterus to contract, helps to move breast milk from the ducts to the nipple and foster the bond between a mother and her baby – it also plays a wider role in how we think and feel.

Serotonin isn’t the only ‘happy hormone’ affected by your gut health, according to a new study