Sex Hormones, the Microbiome, and Autoimmune Risk

From The Institute of Functional Medicine  

The impact of the microbiome on the onset of autoimmune conditions is well established—especially in the connection between ankylosing spondylitis and Klebsiella infection.1 Research on other autoimmune conditions, the microbiome, and the effects of sex hormones is unfolding. For instance, children with type 1 diabetes are known to have dysbiosis when compared to healthy controls.2 This dysbiosis creates a pro-inflammatory state, and in animal models, modulating the microbiome can reduce type 1 diabetes risk.3-4

Strategies to introduce bacteria into high-risk individuals are being explored with fecal transplants in animal models. Transfer of the gut microbiota of adult male non-obese diabetic mice into young female mice led to “elevated testosterone and metabolomic changes, reduced islet inflammation and autoantibody production, and robust T1D protection. These effects were dependent on androgen receptor activity.”3

In a mouse model of lupus, microbiome treatment improved symptoms in female mice and castrated mice but not in intact males,5 reinforcing the role of sex hormones in the link between the microbiome and autoimmunity. The impact of sex hormones on autoimmunity is not new; as far back as 1991,6 prevalence of autoimmune conditions was known to follow a woman’s menarche to menopause, increasing during the former and declining during the latter.7Since the microbiome affects sex hormone production, and vice versa, the role of estrogen and the microbiome in autoimmunity continues to be of interest.8-9 Tailoring treatments for each gender may have beneficial effects in a range of conditions, including IBS.10  LINK