Study links small bowel microbiome differences to women’s health

Small bowel microbiome differences between women and men may help explain why some conditions are more common in women, a study suggests.

The small bowel microbiome is the community of microorganisms living in this part of the digestive tract, where they play vital roles in immune function, metabolism and hormonal regulation.

Researchers found differences between women and men in the composition and organisation of these microbial communities. One bacterial community containing Granulicatella was found only in women.

The study was conducted by investigators at Cedars-Sinai Health Sciences University.

Ruchi Mathur, director of clinical research and clinical operations for the Medically Associated Science and Technology (MAST) Program at Cedars-Sinai and corresponding author of the study, said: “One intriguing finding was a bacterial community containing Granulicatella, which we found only in women.

“Bacteria in this community appear at increased levels in women with polyendocrine metabolic ovarian syndrome, formerly known as polycystic ovary syndrome.”

The researchers also identified differences between women and men in how microbes in the small bowel produce fructans, complex carbohydrates known to trigger digestive symptoms in irritable bowel syndrome (IBS).

IBS is far more common in women than men.

Mathur, who is also a professor of medicine, said: “Our findings show that biological sex is a critical variable in the small bowel microbiome.

“We must consider it as we move toward more personalised approaches to understanding and treating disease.”