Our current medical culture often separates out body systems when treating and diagnosing conditions, but more and more functional medicine is proving that all body systems work intricately together. Hormones, for example, largely impact the gut microbiome, digestion, and absorption, and vice versa. I’ve worked with many clients who come in for symptoms of hormonal imbalance like PMS, painful periods, or severe bloating, and find that by working on their gut health, their hormones improve. I’ve had clients also come in for constipation or diarrhea, or a “nervous stomach” and find relief when they begin to address certain hormones like cortisol or progesterone. Understanding how hormones influence gut health and vice versa can offer insights into many health conditions and allow for long lasting relief.
Central to the relationship between hormones and gut health is the gut-brain axis, a communication network that links the brain with the digestive system. If you’ve ever had “butterflies” in your stomach, you know this connection well. This axis involves various pathways, including neural, hormonal, and immunological routes. Hormones such as cortisol, serotonin, and insulin are key players in this communication.
Cortisol, commonly known as the stress hormone, is produced by the adrenal glands. Chronic stress leads to elevated cortisol levels, which can negatively affect gut health. High cortisol levels can alter the composition of the gut microbiota, reduce intestinal barrier function, and increase gut permeability, often referred to as "leaky gut." This can lead to inflammation and has been linked to conditions like irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). When a body is running in “fight or flight” mode, cortisol is the dominant hormone. A body stuck in elevated cortisol patterns cannot prioritize the detoxification and digestion that occurs at states of rest.
Serotonin is a neurotransmitter often associated with mood regulation, but approximately 90% of the body's serotonin is found in the gut. Produced by enterochromaffin cells in the intestinal lining, serotonin plays a critical role in regulating bowel movements and gut motility. Imbalances in serotonin levels can lead to gastrointestinal issues such as constipation, diarrhea, and IBS. Vice versa, depression and anxiety are often rooted in gut microbiome abnormalities. By soothing the gut, the brain is also soothed.
Insulin, a hormone produced by the pancreas, regulates blood sugar levels and influences gut health. Dysregulation of insulin, as seen in diabetes and metabolic syndrome, can impact the gut microbiota. High blood sugar levels can alter the gut microbiome composition, promoting the growth of harmful bacteria and contributing to inflammation. Conversely, a healthy gut microbiota can improve insulin sensitivity and help maintain metabolic health.
Sex hormones, including estrogen and progesterone, also play a significant role in gut health. These hormones fluctuate throughout the menstrual cycle, pregnancy, and menopause, influencing gut motility, microbiota composition, and intestinal barrier function.
Estrogen has anti-inflammatory properties and supports a healthy gut barrier. Low estrogen levels, as seen in postmenopausal women, can lead to a decrease in beneficial gut bacteria and an increase in gut permeability, contributing to gastrointestinal issues and systemic inflammation.
Progesterone influences gut motility and can lead to constipation during the luteal phase of the menstrual cycle and pregnancy. It also affects the gut microbiome composition, promoting the growth of certain beneficial bacteria. For women that struggle with digestive issues while on their periods, for example, optimizing these hormones makes a huge difference.
The gut microbiome, a diverse community of microorganisms residing in the intestines, plays a critical role in mediating the effects of hormones on gut health. The microbiome can influence hormone levels and metabolism, and hormonal changes can, in turn, alter the composition and function of the microbiome.
Understanding the hormonal connection to gut health has practical implications for managing various health conditions. Strategies to support this balance include:
By looking at how the entire body works together, we can achieve long-lasting healing from within!
Sources:
Article on Cortisol and Gut Health:
Review on Serotonin in the Gut:
Research on Insulin and Gut Microbiota:
Studies on Estrogen, Progesterone, and Gut Health: