Study points to oestrogen-linked pathway for greater gut sensitivity in women

A new study into why women experience more severe gut pain suggests that oestrogen, the female sexual hormone, increases the release of a gut hormone that promotes satiety, boosting serotonin production, and sensitising nerves in the gut that trigger pain response.

A comparative study of male and female mouse models conducted by researchers from South Australian Health and Medical Research Institute and University of California, San Francisco, revealed an oestrogen-dependent pathway that promotes gut sensitivity to toxic stimuli, according to the findings published in the ‘Science’ journal.

“Oestrogen activates a pathway in the colon that increases the release of the gut hormone PYY. PYY then stimulates neighbouring serotonin-producing enterochromaffin cells, boosting serotonin output and sensitising the nerves that send pain messages to the brain,” Stuart Brierley, director of the visceral pain research group at South Australian Health and Medical Research Institute, said.

Gastrointestinal and visceral pain disorders are more common among women, but its reasons remain poorly understood, the researchers said.

The study has also revealed that oestrogen increases the gut’s response to short-chain fatty acids — produced when bacteria break down food — possibly explaining why dietary interventions like low FODMAP diets can reduce symptoms of gastrointestinal distress in some people.

A FODMAP diet restricts the intake of short-chain carbohydrates, common in foods such as garlic, apples, wheat and dairy.

“We now understand that certain foods can feed into this oestrogen-sensitive pathway through the metabolites they produce. This gives us a clearer biological rationale for why dietary changes may help and how they could be refined,” Brierley said.

The researchers said the study links hormonal activity, digestive processes and nerve response, with significant implications for conditions like irritable bowel syndrome (IBS).

“If we can interrupt this (oestrogen-dependent) pathway at the right point, we may be able to reduce chronic gut pain without affecting the normal digestive functions of these hormones,” Brierley said.