What Role Do Hormones Play in IBS?
Do hormones cause gut problems or do gut problems cause hormone problems? Or maybe both. Your gut and your hormones are intricately intertwined. Problems with one can cause problems with the other. Let’s look at which hormones affect your gut and how your gut health affects your hormones.
Which Hormones Affect Your Gut and How?
Which hormones might affect your gut? Well, there are reproductive hormones (estrogen, testosterone, progesterone, prolactin, DHEAs, etc.), gut hormones (leptin, ghrelin), stress hormones (cortisol) and thyroid hormones. All of these may influence your digestive tract.
Reproductive Hormones and Digestion
Twice as many women as men are affected by irritable bowel syndrome (IBS), suggesting a role for sex hormones in causing or contributing to the development of IBS.
According to some studies, it appears that there is an association between increased blood levels of the hormone prolactin and IBS. Prolactin helps women to breastfeed their infants. This hormone can also be increased when one is under stress. One theory as to why this happens is that the increased prolactin levels may cause oversecretion of cholecystokinin, inducing the development of IBS. Cholecystokinin (CCK), is a digestive hormone that is released when food from your stomach reaches the first part of your small intestine.
Estrogen and Progesterone
Twice as many women as men are affected by irritable bowel syndrome (IBS), suggesting a role for sex hormones in this condition.
Ovarian hormones vary widely throughout a woman’s menstrual cycle. They affect both sensation and movement in your gut in both healthy and IBS populations. They can moderate pain by interacting with nerve balancing systems and the emotional system that is responsible for the perception of pain in your gut. These hormones also modulate your susceptibility and response to stress. Stress is a pivotal factor in IBS occurrence and symptom severity. For instance, estrogen can cause an increased stress response that promotes immune activation and decreases your gut barrier function.
The Migrating Motor Complex and Hormones
The migrating motor complex, or MMC, is a pulsatile, muscular movement that propels food and waste through your digestive tract. Normal MMC function is a prerequisite for normal gut function. One study that compared the MMC of women at particular points of their menstrual cycle with that of men found that early in the cycle (day 1 of your period to ovulation) MMC cycle duration during sleep was lengthened. The higher the estrogen level, the longer the MMC cycle duration. Where in the middle of the luteal phase MMC cycle duration during sleep was shorter with higher serum progesterone levels and longer with lower progesterone.
Histamine, IBS and Estrogen
Histamine is a chemical that is released by white blood cells known as mast cells. Histamine is responsible for the typical allergy symptoms of sneezing, runny nose, and watery eyes. It has also been implicated in IBS. A study on progesterone and histamine release showed lower histamine release in the presence of progesterone. Mast cells show a high affinity for estradiol (estrogen) receptors and estradiol increases mast cell secretion. Increased mast cell density and activity in the gut may correlate with symptoms of hypersensitivity in the gut.
Your Hormones and Your Microbiome
The composition of your gut flora reflects both your genetics and your lifestyle. It is in a dynamic state of flux depending on factors like stress, diet, sleep, and medication use. Your gut micro-organisms exert both local and systemic effects. Having a messed-up gut ecology (dysbiosis) could contribute to the risk of developing not only gut problems but more systemic health problems. Your gut bacteria are capable of metabolizing estrogen and also modulating your serum estrogen levels. Conversely, estrogen-like compounds, such as BPA from plastic, may promote the growth of certain kinds (not necessarily good kinds) of gut bacteria.
Testosterone and IBS
One study in young males found that sufferers of IBS, whether it was constipation-predominant or diarrhea-predominant IBS, had higher levels of testosterone and also a hormone-binding protein known as sex hormone-binding globulin (SHBG). Higher SHBG levels may be reflective of higher testosterone but also higher estrogen and DHT. As mentioned previously, estrogen affects stress-response, your microbiome and also the migrating motor complex.
FODMAPs, Gut Hormones and IBS
The density of gut hormone-producing cells is low in IBS patients. This abnormality may be the direct cause of IBS symptoms. This decreased density is probably caused by a low number of stem cells and low conversion of these cells into hormone-producing cells. Fermentable carbohydrates (FODMAPs) are digested by gut bacteria into by-products that decrease gut stem cells. A low FODMAPs diet or altering the gut bacteria seem to help restore appropriate numbers of gut stem cells.
Leptin is a hormone that is released by your fat cells. It signals to your brain that you are full and decreases your appetite and food cravings. In obese people, excessive amounts of leptin are excreted by the fat cells and the brain responds poorly to it. This is known as leptin resistance. The person’s brain doesn’t get the message to stop eating, further compounding their obesity problem. Giving your digestive tract adequate time between putting food into it, allows for better, more thorough digestion. A meal takes between 2-4 hours in the stomach to fully digest. Layering more food on top of the food that hasn’t finished digesting, leads to a mix of partially digested and whole, undigested food. Not optimal conditions for complete and healthy digestion.
Research on diarrhea-predominant IBS (IBS-D), identified increased leptin in the lining of the digestive tract. The mast cell activation rate in these patients was also increased. The authors speculated that leptin and increased mast cell activation may play a role in IBS-D.
Ghrelin stimulates your appetite and your release of growth hormone. It is produced in your stomach and small intestine. Small amounts are also released from your pancreas and brain. Ghrelin stimulates your appetite, causing you to digest more food and store more fat. It also appears to help control insulin release and plays a protective role in your cardiovascular health. Ghrelin is released in response to stressful situations. This is part of the reason why we reach for food when we feel stressed. Overproduction of ghrelin due to stress, means piling more food into your digestive tract than you really need. Overeating contributes to poor digestion and IBS symptoms.
Blood levels of ghrelin have been shown to be higher in patients with IBS-D.
Corticosteroids and Your Gut
Apart from inflammation of the intestinal lining, nerve inflammation is probably involved in the cause of IBS via the “gut-brain” axis. Your gut-brain axis is the connection between your digestive tract and your nervous system and your brain. This results in altered hormone pathways and changes in the receptor genes for cortisol, cortisone, and corticosterone (these are collectively known as corticosteroids). This gives rise to an overall pro-inflammatory picture and dysregulated HPA (hypothalamic-pituitary-adrenal) axis and serotonin-related functioning, which could, at least partially, account for the symptoms of IBS.
Your Gut Bacteria and Your Hormones
The bacteria in your gut regulate your estrogen level through the secretion of an enzyme known as β-glucuronidase. This enzyme unpackages estrogen that has been packaged up for excretion, releasing it in its active form. In this way, your gut bacteria, depending on the mix, increase or decrease your estrogen level. Having the right balance of gut bacteria helps to maintain healthy estrogen levels. An alteration in your gut flora and therefore your circulating estrogen level may contribute to obesity, metabolic syndrome, endometrial hyperplasia, endometriosis, polycystic ovary syndrome, fertility, cardiovascular disease (CVD) and altered cognitive function.
Thyroid Hormones and IBS
One common symptom of hypothyroidism is constipation. If you think of your thyroid like the gas pedal for your car. Your thyroid determines the speed with which everything else runs. If your gut is working slowly, it can be because it isn’t receiving enough gas from your thyroid.
A 2017 study found an association between hypothyroidism and IBS and an elevated antibody in the blood known as IgG2. Immune reactions to food can precipitate the release of IgG antibodies. This is the basis for our food sensitivity test. If you would like to try lowering your IgG antibodies to see if that helps your IBS and thyroid, book an appointment to discuss food sensitivity testing.
The digestive tract manifestations of hypothyroidism are due to reduced movement. Hashimoto’s thyroiditis, an autoimmune disorder that is the most common cause of low thyroid function, may be associated with symptoms that are related to this decreased movement including difficulty swallowing or heartburn. Indigestion, nausea, or vomiting may be due to delayed emptying of the stomach. Slowed movement through the small intestine adds to abdominal discomfort, gas, and bloating in those with bacterial overgrowth (SIBO). Because of an existing autoimmune disorder, there may be additional autoimmune disorders, such as autoimmune gastritis. This reduces stomach acid production that has implications for adequate digestion. Constipation may result from diminished motility. Grave’s disease or hyperthyroidism is accompanied by normal stomach emptying but with low acid production. The time for food to pass through the digestive tract is accelerated, resulting in diarrhea.
Symptoms usually resolve with treatment of the thyroid disease.
What Can You Do?
As you can see, there are a number of possible hormonal influences on your digestive tract. If you are suffering from IBS, constipation, diarrhea, SIBO, bloating, or gas there may be a hormonal influence on your digestive tract.
Here’s how I can help:
- Comprehensive hormone testing, interpreted within the context of what is IDEAL for you, not just based on the “lab ranges” which are not set based on what is optimal for you
- Determine the root cause of your gut problems and address that
- Testing for and correction of all of the contributing factors to your gut issues: comprehensive stool testing, food sensitivity testing, hormone testing
By Dr. Pamela Frank, BSc(Hons), Naturopathic Doctor