Sex hormone levels linked to gut microbiota composition, diversity

Sex hormone levels are associated with the gut microbiota composition or diversity, according to a study, noting that such relation may contribute to the sex-based variations seen in disease pathogenesis.

A team of investigators searched four bibliographic databases in July 2020 using terms related to microbiota, microflora, sex hormones, testosterone, and oestrogen. They included studies investigating the association between sex hormones and the microbiota composition or diversity using next-generation sequencing.

Of the 10,468 records identified, 13 studies met the eligibility criteria. High oestrogen levels in healthy women correlated with a higher abundance of Bacteroidetes, a lower abundance of Firmicutes, the Ruminococcaceae family, and increased diversity. In healthy, men, elevated testosterone levels correlated with Ruminococcus, Acinetobacter, and an increased microbial diversity. 

Escherichia and Shigella spp. were associated with increased testosterone in healthy women, while Ruminococcus spp. was negatively associated with elevated testosterone levels.

Of note, women with altered testosterone/oestrogen profiles (such as in polycystic ovary syndrome) showed a different gut microbiota relative to healthy women.

“Factors such as age and medical conditions are implicated in the associations observed and should be accounted for in future studies,” the investigators said. “As the understanding of the complex symbiotic relationship between humans and their gut microbiota increases, microbiota modulation could be an attractive option for the prevention and treatment of gastrointestinal disorders.”