Estrogen: The Link Between Microbiome, Menopause & Metabolic Health

The diversity of the microbiome has profound implications for metabolic health. The micro-organisms that we host in our gastrointestinal tract maintain our gut integrity, break down complex carbohydrates to improve energy extraction from food, produce vitamins and minerals, aid in digestion and absorption, ferment dietary fibers and protect us against pathogens. Maintaining a delicate balance in the diversity of the host-microbiome relationship is crucial for disease prevention and healthy aging. 

Studies on the microbiome are emerging as a new and exciting frontier of science. However, how the microbiome interacts with the endocrine system to modulate metabolic health is still one of the less explored avenues in microbiome research. This blog aims to shed light on the intertwined roles of gut microbiota and estrogen on metabolic health for women as they transition into .

Estrogen, Microbiome and Metabolic Health

Estrogen and the microbiome regulate weight gain and lipid deposition independent of each other. 

By increasing the density of small intestinal villi capillaries, gut microbiota influence gastrointestinal physiology and gut motility, and thus promote caloric extraction from the diet. Studies in humans show that a drastic reduction in the diversity of gut microbes (also called dysbiosis) is enough to cause functional changes related to weight gain [1]. Owing to the essential role of the gut ecosystem in maintaining host physiology, unfavorable alterations in the composition of the microbial make up can trigger a wide range of physiological disorders, including low-grade inflammation, metabolic disorders, excess lipid accumulation, and loss of insulin sensitivity, which increase the risk of developing metabolic diseases.

Estrogen, in proper amounts, is also recognized as a key element in preserving metabolic health, by keeping weight down, reducing abdominal fat and improving glucose tolerance.  Recent studies help illuminate another, less recognized role of estrogen in metabolic health, and it has to do with the gut. 

Estrogen is Protective for Microbial Diversity

Adequate estrogen levels are important for a multitude of functions outside of its reproductive role. Specific to the microbiome, estrogen and estrogen-like compounds prevent the loss of and promote growth and proliferation of beneficial bacteria [2]. For example, animals treated with estrogen have significantly higher microbial diversity than controls [3]. 

Research shows that microbial diversity is key for maintaining a healthy metabolic profile [1]. The study by Turnbaugh (2009) specifically illuminates how dysbiosis can preferentially turn on genes and inappropriately activate pathways involved in sugar and carbohydrate metabolism in overweight but not in lean individuals. The aberrant upregulation of these genes is suspected to contribute to the metabolic profile observed in overweight persons.

Estrogen Helps Maintain the Integrity of the Gut

Cells that line the gut comprise a barrier, so that large molecules (food particles, digestive enzymes, cytokines, etc.) stay where they ought to – inside the gastrointestinal tract. A healthy and diverse microbiome ensures that the gut barrier maintains its integrity. So does estrogen! Sufficient estrogen levels are needed to form the epithelial layer of the gut and keep it healthy, elastic and impervious to the contents of the gut [4]. Gut barrier integrity is critical in the context of metabolic health because any changes to intestinal permeability are likely to be detrimental to a healthy weight profile and may play a role in T-cell activation leading to the development of food sensitivities, adipose inflammation and autoimmune diseases. 

Estrogen Decreases Inflammation

Additionally, estrogen decreases pathogenic populations of bacteria and reduces lipopolysaccharide (LPS) -induced inflammation. LPS, produced by Gram-negative bacteria, can impair the lining of the gut, cross into the rest of the body and elicit a strong immune response. Estrogen working against enteric pathogens is yet another example of estrogen’s protective functions on the gut.