Throughout life, hormones like androgens, estrogen, and progesterone do more than just handle reproductive stuff. During puberty, they not only help our reproductive organs grow but also affect how other parts of our body develop. 1-4 As we get older, these hormones keep working, helping our immune system and keeping us healthy, from our bones to our brains.
But what about the gut? Recent studies5 show that the bacteria living in our gut play a big role in how our bodies use hormones. They have special enzymes that change hormone molecules, like estrogen, making them more active in our bodies.
Scientists are finding that the mix of bacteria in our gut might be different depending on our gender. These bacteria seem to be influenced by hormones, which raises questions about how our hormone levels might affect our gut bacteria. 6-8 This new research is making us rethink how hormones, gut health, and diseases are all connected, pushing us to find personalized ways to balance hormones and keep our guts healthy.
Gut Microbiota & Sex Hormone Interactions: Chronic Disease Impact
The way our gut bacteria interact with sex hormones and how this affects chronic diseases is an area scientists are still exploring. 9-10They're finding that the mix of gut bacteria might differ between men and women, and this could have a role in how diseases develop and how they're treated. For example, research suggests that there's a complex relationship between sex hormones, gut bacteria, and diseases like obesity, metabolic syndrome, and type 2 diabetes.
Recent studies 11 have looked into how testosterone levels in men with type 2 diabetes might affect their gut bacteria. They found that men with low testosterone had different gut bacteria compared to those with normal levels. Interestingly, having low testosterone seemed to make the gut bacteria more imbalanced, which could be linked to worse disease markers.
Researchers have been looking into how sex hormones and the mix of gut bacteria might affect our gut-brain connection, which could be important for understanding and treating mental health issues. Studies in both animals and humans suggest that there's a back-and-forth relationship between sex hormones, gut bacteria, and how our brain functions.
Testosterone & Estrogen Levels
In a recent study, scientists checked out how different gut bacteria might relate to psychological symptoms like depression, memory, stress, and sleep. 13Surprisingly, they found that while the types of bacteria were similar between guys and gals, the link between gut bacteria and how severe these symptoms were seemed to vary depending on gender. In fact, ladies tended to report more severe symptoms compared to guys, suggesting a gender-specific connection between gut bacteria and mental well-being.
One way scientists are digging into the connection between sex hormones and gut bacteria is by studying the levels of certain gut bugs in different groups of people, while also checking their hormone levels. A systematic review done in 2022 looked at 13 studies involving 852 people, mostly women, to see how sex hormones like testosterone and estrogen might affect the variety of gut bacteria in humans.
Here’s what they found:
- In healthy women, higher estrogen levels were linked to more of a bacteria group called Bacteroidetes and less of another group called Firmicutes. Having a good balance of these bacteria is tied to a healthy gut and lower body weight.
- For men, higher testosterone levels were connected to more Ruminococcus and Acinetobacter bacteria, and a wider variety of gut bugs. Ruminococcus is especially important for breaking down sugars into nutrients that our bodies can use.
- Elevated testosterone levels in women were associated with certain potentially harmful bacteria like Escherichia and Shigella, while beneficial bacteria like Ruminococcus decreased. This shift in gut bacteria was also seen in women with conditions like polycystic ovary syndrome (PCOS)14.
- Overall, these studies show that there's a clear link between sex hormones and the variety of gut bacteria, but we still have a lot to learn about how exactly these hormones affect our gut bugs and vice versa, especially when it comes to testosterone.
Scientists are still unraveling the intricate dance between hormones and our gut to figure out if changes in hormone levels drive shifts in gut bacteria, if it's the other way around, or if both have an equal say in the matter. As this field of study expands, there's a growing opportunity to tailor treatments that not only balance hormones but also support a healthy gut environment, benefiting both hormone levels and gut microbial diversity.
- Shepherd R, Cheung AS, Pang K, Saffery R, Novakovic B. Sexual dimorphism in innate immunity: the role of sex hormones and epigenetics. Front Immunol. 2021;11:604000. doi:3389/fimmu.2020.604000
- Quatrini L, Ricci B, Ciancaglini C, Tumino N, Moretta L. Regulation of the immune system development by glucocorticoids and sex hormones. Front Immunol. 2021;12:672853. doi:3389/fimmu.2021.672853
- Szoeke C, Downie SJ, Parker AF, Phillips S. Sex hormones, vascular factors and cognition. Front Neuroendocrinol. 2021;62:100927. doi:1016/j.yfrne.2021.100927
- Emmanuelle NE, Marie-Cécile V, Florence T, et al. Critical role of estrogens on bone homeostasis in both male and female: from physiology to medical implications. Int J Mol Sci. 2021;22(4):1568. doi:3390/ijms22041568
- Hussain T, Murtaza G, Kalhoro DH, et al. Relationship between gut microbiota and host-metabolism: emphasis on hormones related to reproductive function. Anim Nutr. 2021;7(1):1-10. doi:1016/j.aninu.2020.11.005
- Wallis A, Butt H, Ball M, Lewis DP, Bruck D. Support for the microgenderome: associations in a human clinical population. Sci Rep. 2016;6:19171. doi:1038/srep19171
- Valeri F, Endres K. How biological sex of the host shapes its gut microbiota. Front Neuroendocrinol. 2021;61:100912. doi:1016/j.yfrne.2021.100912
- Shin JH, Park YH, Sim M, Kim SA, Joung H, Shin DM. Serum level of sex steroid hormone is associated with diversity and profiles of human gut microbiome. Res Microbiol. 2019;170(4-5):192-201. doi:1016/j.resmic.2019.03.003
- Maffei S, Forini F, Canale P, Nicolini G, Guiducci L. Gut microbiota and sex hormones: crosstalking players in cardiometabolic and cardiovascular disease. Int J Mol Sci. 2022;23(13):7154. doi:3390/ijms23137154
- Xu L, Huang G, Cong Y, Yu Y, Li Y. Sex-related differences in inflammatory bowel diseases: the potential role of sex hormones. Inflamm Bowel Dis. 2022;28(11):1766-1775. doi:1093/ibd/izac094
- Santos-Marcos JA, Mora-Ortiz M, Tena-Sempere M, Lopez-Miranda J, Camargo A. Interaction between gut microbiota and sex hormones and their relation to sexual dimorphism in metabolic diseases. Biol Sex Differ. 2023;14(1):4. doi:1186/s13293-023-00490-2
- Ganci M, Suleyman E, Butt H, Ball M. Associations between self-reported psychological symptom severity and gut microbiota: further support for the microgenderome. BMC Psychiatry. 2022;22(1):307. doi:1186/s12888-022-03947-7
- Moslehi N, Zeraattalab-Motlagh S, Rahimi Sakak F, Shab-Bidar S, Tehrani FR, Mirmiran P. Effects of nutrition on metabolic and endocrine outcomes in women with polycystic ovary syndrome: an umbrella review of meta-analyses of randomized controlled trials. Nutr Rev. 2023;81(5):555-577. doi:1093/nutrit/nuac075