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Does Your Biological Sex Influence Your Gut Microbiome?

Theresa Hardy, PhD, RN

Do you spend much time thinking about the residential community you live in? Probably, because I think most of us would go to great lengths to ensure our community is happy, healthy, and thriving.

Do you feel the same way about your microbial community – otherwise known as your gut microbiome? Even though your microbiome is fully integrated into your metabolism,1 you probably don’t spend as much time thinking about it as you should. And recent advances in understanding the microbiome have given us much more to know about just how involved this microbial community is in our health.

The microbial makeup of our gut not only contributes to how we feel daily but it can also predispose us to or protect us from several health conditions.

Just like the diversity of the community we live in matters, the diversity of our gut microbiome matters also. What factors will affect the diversity of our microbiome?

One factor is gender. Researchers have determined that the gut microbiome differs significantly between men and women, with gender-dependent hormone levels being a primary biological driver of these differences.2,3 Who would have thought that hormone levels had anything to do with the gut?

The effect of hormone levels on the microbiome has been demonstrated in twin studies, in which scientists examined the microbial composition of opposite-sex and same-sex twins before and after puberty. Although their microbial composition was similar before puberty in both kinds of twins, clear differences were observed after puberty in the opposite-sex twins.4 These findings suggest that hormones, particularly estrogen and testosterone, have activational effects on the gut microbiome.4,5

Studies in mice provide further evidence to confirm this hypothesis, leading the researchers who studied it to call it this interaction between the gut microbiome and biological sex the “microgenderome.4

What are the differences between male and female microbiomes? 

The diverse microbial species that characterize the gut microbiome is described in two ways – alpha diversity and beta diversity. Alpha diversity refers to the number of different species within a specific community or individual sample. Beta diversity refers to how similar one community or individual sample is to another.6

Alpha diversity is likely the way most of us understand the term diversity – we would consider a menu to be diverse if it had multiple options. Beta diversity takes it one step further, capturing the degree or level of diversity between one distinct species and another. So, to use the menu example, we might describe a menu as especially diverse if it also included distinct cuisines (how different the options are from each other).

Studies have shown that women have greater alpha diversity in their gut microbiome. For example, studies have found that men have a higher abundance of Bacteroides species of bacteria (including Prevotella and Bacteroides thetaiotamicron) than women do, but a lower abundance of Clostridia, Methanobrevibacter, and Desulfovibrio.6

Why does it matter?

The phenomena of the microgenderome – differences in the gut microbiome between males and females – perhaps partially explains the gender differences observed in metabolic illnesses like type 2 diabetes and cardiovascular disease.3 For example, men are at higher risk of developing diabetes before puberty, and women are at higher risk of developing it after menopause.1 And women are more predisposed to obesity and metabolic syndrome than men.3

When scientists examined the gut microbiome in males and females who had metabolic syndrome, they found different dysbiosis (microbial imbalances) in men and women. They suggest this differential dysbiosis perhaps impacts the relative incidence of metabolic syndrome in men and women.

Interestingly, in the same study, the researchers examined how two recommended diets for metabolic syndrome – the Mediterranean Diet and a low-fat diet – altered the gut microbiome in men and women. They found that while the response to the Mediterranean Diet was similar between men and women, some changes in the gut microbiome were not favorable in men on a low-fat diet.3 They found a higher abundance in men of Desulfovibrio, a hydrogen sulfide-producing bacteria, after consumption of a low-fat diet. This bacterial genus is related to gastrointestinal disorders such as ulcerative colitis, Crohn’s disease, and irritable bowel syndrome.3

This is significant! Various dietary recommendations, like total calorie amounts, are not one-size-fits-all, and not every recommendation will have the same effect on men and women.

Another important takeaway is that hormones matter. So, if your gut microbiome is imbalanced, then it could be impacting your hormone levels, as well as your mood, energy levels, and more. Discover the diversity of your gut microbiome and how it might be impacting your everyday life with a simple at-home GutBio™ test.

1.    Santos-Marcos J, Rangel-Zuñiga O, Jimenez-Lucena R, et al. Influence of gender and menopausal status on gut microbiota. Maturitas 2018;116:43-53. doi:10.1016/j.maturitas.2018.07.008

2.    Haro C, Rangel-Zúñiga O, Alcalá-Díaz J, et al. Intestinal microbiota is influenced by gender and Body Mass Index. PLoS One 2016. doi:10.1371/journal.pone.0154090

3.    Santos-Marcos J, Haro C, Vega-Rojas A, et al. Sex Differences in the Gut Microbiota as Potential Determinants of Gender Predisposition to Disease. Mol Nutr Food Res 2019;63(7):1-11. doi:10.1002/mnfr.201800870

4.    Levy G, Solt I. The human microbiome and gender medicine. Gend Genome 2018;2(4):123-127. doi:10.1177/2470289718811764

5.    Shin J-H, Park Y-H, Sim M, et al. Serum level of sex steroid hormone is associated with diversity and profiles of human gut microbiome. Res Microbiol 2019 doi:10.1016/j.resmic.2019.03.003

6.    Thackray V. Sex, microbes, and polycystic ovary syndrome. Trends Endocrinol Metab 2019. doi:10.1016/j.tem.2018.11.001