Gay Men Tend To Have Different Gut Bacteria
Why they have gut bacteria that resemble traditional cultures
New research reveals that gay men tend to have a distinctive mix of gut bacteria that is more similar to people from traditional cultures than Western cultures. This surprising finding suggests that sexual orientation and practices may shape our microbiome in ways we are just beginning to understand.
In the study published in Cell Host & Microbe, researchers analysed stool samples from 93 gay men and 31 straight men using DNA sequencing. They found gay men had much more diverse gut bacteria compared to straight men.
Specifically, gay men had high levels of bacteria from the Prevotella genus. These bacteria are abundant in people from traditional hunter-gatherer and rural farming cultures in developing nations. They are adapted to plant-heavy diets that are high in fibre and low in fat and animal protein.
In contrast, straight men had high levels of Bacteroides bacteria, which predominate in Western cultures with diets heavy in animal fat and protein.
Overall, the microbiome of gay men in the study shared about 33 of their 50 most common gut bacteria species with traditional cultures. They only shared 15 species in common with typical Western people.
Why Do Gay Men Resemble Traditional Cultures Microbiologically?
This finding raises the obvious question — why do gay men have gut bacteria that are so much more similar to traditional cultures than their Western counterparts?
The researchers believe the reason comes down to differences in sexual practices and lifestyles between gay and straight men. Specifically, they found links between certain intimate acts and presence of Prevotella bacteria.
For example, 70% of the gay men had multiple strains of a specific type of Prevotella bacteria called Segatella copri, compared to only 30% of straight men. The Segatella copri bacteria is adapted to colonize the mucus membranes found in the rectum and mouth.
The study suggests that certain sexual practices common in gay men provide an environment that favours growth of Prevotella strains like Segatella copri. In turn, these bacteria can potentially influence health in ways we don’t yet fully grasp.
Implications for Understanding the Microbiome
This research demonstrates how sexual orientation and intimate behaviours may lead to radical differences in gut microbiome composition. For such a fundamental factor impacting health, it’s surprising sexual practices are rarely considered in microbiome studies.
The findings illustrate we need to look beyond the usual factors like diet, medication, lifestyle, and ethnicity when interpreting microbiome data. Sexual orientation is shaping microbiomes too, but you cannot tell that from a stool sample alone!
As intimate practices can deeply impact the microbiome, perhaps we need to reconsider “normal” when it comes to bacteria. The Prevotella-dominated gut signature in gay men is linked to better health outcomes in some studies.
So is it really abnormal compared to Western Bacteroides-dominated microbiomes?
Much more research is needed to unravel the complex influences of sex and sexuality on the gut microbiome. But these early findings suggest intimate behaviours may lead to radical differences in our gut ecosystems. Factoring in sexual orientation and practices could allow more personalized microbiome medicine in the future.
Key Findings
- Gay men had more diverse gut bacteria than straight men.
- Gay men had high levels of Prevotella bacteria, which are common in traditional cultures with plant-based diets.
- Straight men had high levels of Bacteroides bacteria, which are common in Western cultures with high-fat diets.
- 70% of gay men had multiple strains of the Segatella copri bacteria, compared to only 30% of straight men.
- Gay men’s gut bacteria were more similar overall to those of traditional cultures than Western cultures.
Significance
This study highlights how sexual orientation and practices may influence health through gut bacteria. Understanding these connections could lead to tailored probiotics or dietary recommendations for different groups.
Sources:
DOI:https://doi.org/10.1016/j.xcrm.2024.101426
