Gut Health and Hormones: How the Gut Influences Hormone Balance

Your hormone labs look “normal.” You’re eating well, sleeping, exercising. So why are you still bloated, moody, gaining weight, or watching your cycle go haywire? I hear this every week, and so many of these patients have been told there’s nothing wrong. Don’t get me wrong, labs matter. But if you still don’t feel well, your gut deserves a closer look. The gut microbiome is now considered a full-fledged endocrine, hormone-secreting organ! In this post, I’ll explain how gut health and hormones affect each other, which signs to watch for, and where to start.

Key Takeaways

Your gut microbiome helps regulate the production, metabolism, and balance of hormones, including insulin, cortisol, estrogen, progesterone, and testosterone.

Gut bacteria called the estrobolome help decide whether estrogen is cleared from your body or recirculated.

The relationship runs both ways: an unhealthy gut can disrupt hormones, and declining hormones can change your gut.

Bloating, constipation, and digestive symptoms that shift with your cycle are worth investigating.

Healing the gut starts with removing inflammatory foods, feeding your beneficial bacteria, daily bowel movements, stress management, and sleep.

What Is the Gut Microbiome?

Your gut microbiome is the community of trillions of bacteria, plus fungi and viruses, that lives in your digestive tract, mostly in the large intestine. These microbes help break down food, make certain vitamins, support your immune system, and produce short-chain fatty acids that calm inflammation in the gut and the brain. Most of the serotonin and dopamine that shape your mood are produced in the gut, too!

When the community is healthy and balanced, we call it eubiosis. When harmful bacteria start to outnumber the beneficial ones, we call it dysbiosis. Your diet, stress, medications, sleep, age, and environment all push your gut one way or the other.

Why Your Gut Matters for Your Hormones

In conventional medicine, specialists tend to focus on one organ at a time. But your body is a system of systems, and the endocrine system touches every one of them, head to toe. The gut is right in the middle of that conversation.

When I sat down with functional endocrinologist Dr. Cassie Smith on The Dr. Terri Show, she described a group of patients, mostly women, whose hormones she had optimized. Their estrogen, progesterone, testosterone, and thyroid all looked good. They were eating well, sleeping well, and exercising. Yet they kept gaining weight, and their insulin and inflammation kept climbing. When she looked deeper, she found that the patients who “looked perfect on paper” had terrible guts. Her conclusion matches what I’ve seen for years: even when you fix the hormones, if you don’t fix the gut, people often still don’t feel well.

How Does Gut Health Influence Hormone Balance?

Several pathways connect the two. These are the ones I find most important to understand -> 

The Gut and Estrogen Metabolism

Your liver processes estrogen and packages its used, or “bad,” metabolites to be sent to the bowel for removal. That’s where the estrobolome comes in. The estrobolome is the collection of gut bacteria that metabolize estrogen. When harmful bacteria overgrow, they increase an enzyme called beta-glucuronidase. Beta-glucuronidase unpackages those estrogen metabolites, so instead of leaving your body, they’re reabsorbed into the bloodstream (Baker et al., 2017; Ervin et al., 2019). The recirculation of these more harmful metabolites is thought to raise the risk of estrogen-related conditions, including endometriosis, infertility, and breast cancer.

The Gut-Brain-Hormone Connection

Your gut has its own nervous system, often called the “second brain,” and it is in constant two-way conversation with the brain in your head (Carabotti et al., 2015). Your endocrine system sits right in that same conversation. That’s why mood, digestion, and hormone symptoms so often show up together.

Here it is again: stress! Chronic stress raises cortisol and adrenaline, which can speed up or slow down digestion, make the gut lining more permeable, and shift the balance of your gut bacteria. Toxic relationships and unresolved emotional stress count, too. An unhappy gut then sends stress signals right back to the brain.

Gut Health, Insulin, and Blood Sugar

An overgrowth of harmful bacteria in the gut can lead to insulin resistance and elevated cortisol, which can contribute to type 2 diabetes and other metabolic disorders like PCOS. Dr. Smith pointed out that your regular blood work often holds clues. When the gut is struggling, she frequently sees inflammatory markers like CRP climb, along with insulin, cortisol, or both.

Inflammation and the Gut Lining

Inflammation is a root cause I come back to again and again, and the gut is frequently where it starts. Your intestinal lining is meant to be a tight barrier. When it becomes damaged, what functional providers call leaky gut, bacterial fragments called lipopolysaccharides (LPS) can slip into the bloodstream. LPS are among the most inflammatory substances in the body, and chronic inflammation interferes with insulin, thyroid function, and the way your cells respond to hormones. Leaky gut isn’t widely recognized as a diagnosis in conventional medicine, and research is still evolving. But in my practice, healing the gut lining is often the missing piece.

Feeding Yourself or Feeding Your Bad Bacteria?

Digestion matters, too. If you aren’t breaking down your food properly, whether from an infection like H. pylori or years on an acid-blocking medication, Dr. Smith explained that “instead of feeding ourselves when we eat, we’re feeding our bad bacteria.” You end up short on the micronutrients your body needs to make hormones, while the harmful bacteria thrive. The result? Bloating, a growing waistline, and hormones that can’t keep up.

When Hormones Change, Your Gut Changes Too

This is the part most people never hear. The connection doesn’t just run from the gut to your hormones. It runs the other way, too.

Estrogen helps regulate gut motility, immune function in the gut, and the makeup of your microbiome. It even encourages the growth of bacteria that produce beneficial short-chain fatty acids. When estrogen drops, as it does in menopause, gut motility, immunity, and the microbiome can all change. Estrogen deficiency after menopause in women who aren’t on hormone replacement has also been linked to a higher risk of colon cancer.

Progesterone matters, too. Dr. Smith described how losing progesterone in your 40s can set the stage for leaky gut and bacterial overgrowth. LPS from those bacteria then push your insulin up, cortisol is often already running high, and the weight starts to creep on. It becomes a cycle: hormones affect the gut, and the gut affects your hormones.

Signs Your Gut Health May Be Affecting Your Hormones

• Your symptoms are real, and they often overlap. Patterns that may point to a gut and hormone connection include:
• Bloat that builds in the days before your period
• Constipation or diarrhea that fluctuates with your cycle
• Digestive issues that appear or change during perimenopause or menopause
• PMS symptoms that feel stronger than they used to
• Stubborn fatigue or brain fog that rest doesn’t touch
• Sugar cravings and energy crashes
• Anxiety, low mood, or poor sleep alongside digestive symptoms
• Weight gain around the middle, even when you’re “doing everything right”

No single item on this list confirms a gut problem, since thyroid issues, nutrient gaps, and other conditions can look similar. If several sound familiar, it’s worth a conversation with a provider who looks at digestive function and hormones together.

The Gut-Breast Axis: Another Important Connection

Researchers are also studying the gut-breast axis, which asks whether the bacteria that process estrogen may influence breast tissue health. This research is still emerging (Kwa et al., 2016). We cover it in more detail in our blog post on the gut-breast axis [link]. For now, it’s one more reason to take care of your microbiome.

How to Support Your Gut Health for Better Hormonal Wellbeing

Healing the gut is simple, but not always easy, and it takes time. An unhealthy gut usually develops slowly over years, so it won’t turn around overnight. Here’s where I start with my patients.

Remove Inflammatory Foods

I cannot stress diet enough. The Standard American Diet, and notice the acronym is SAD, is full of calorie-dense, nutrient-poor foods. Start by removing anything that comes in a package. Processed foods, added sugars, high-fructose corn syrup, seed oils, and artificial sweeteners like sucralose top the list, and gluten for many people.

Eat for a Diverse Microbiome

Fill your plate with a variety of fiber-rich vegetables and fruit, plus lean protein and healthy fats. A Mediterranean-style diet is a great model. Make room for cruciferous vegetables like broccoli, cabbage, and Brussels sprouts. They contain DIM, which helps move estrogen toward its healthier metabolic pathway. Most of us don’t eat nearly enough of them, so ask your provider whether a DIM supplement makes sense for you.

Add Prebiotic and Probiotic Foods

Prebiotic foods like garlic, onions, and asparagus feed your beneficial bacteria. Probiotic foods like plain yogurt, kefir, sauerkraut, and kimchi supply live bacteria. A probiotic supplement may help some people, but strains differ, so ask your provider which one is right for you.

Make Sure You’re Pooping Every Day

It’s one of the most overlooked questions in medicine. Your bowels are the exit route for used hormones. When things move slowly, those estrogen metabolites sit in the gut longer and have more chance to be reabsorbed. Aim for a comfortable bowel movement every day, drink enough water, and bring persistent constipation or diarrhea to your provider.

Limit Endocrine Disruptors

Plastics, pesticides, and other chemicals can mimic or block your hormones. Swap plastic water bottles and food containers for glass or stainless steel, and never heat food in plastic.

Manage Stress and Protect Your Sleep

Chronic stress and short sleep disrupt both your gut and your cortisol rhythm. Sleep is when your body makes hormones and does its cleanup work. A walk after dinner, a few minutes of breathwork, and a consistent bedtime are simple places to begin. And skip the trending cleanses you see on social media. Your gut needs support, not punishment.

Test, Don’t Guess

If symptoms persist, a functional provider can dig deeper. A comprehensive stool test such as the GI-MAP looks at the balance of beneficial and harmful bacteria, checks for pathogens like parasites, yeast, and H. pylori, and measures markers of inflammation and digestion. Paired with a full hormone panel, thyroid, insulin, cortisol, and inflammatory markers like CRP, it gives you a real picture of what’s going on.

Your gut and your hormones are in conversation all day long. When digestion is off, hormones can feel off, and when hormones shift, digestion often follows. You are not broken, and your symptoms are real. They are signals worth following. Dr. Smith’s best advice to listeners was simple: listen to your gut. “Even though your labs are normal, keep listening to your gut and advocate for yourself until you find someone to be on your team.” I couldn’t agree more. Start with one or two changes, give your body a few weeks to respond, and find a provider who will look at the whole picture.

Ready to Go Deeper?

Listen to my full conversation with Dr. Cassie Smith on The Dr. Terri Show EPISODE 51, plus more episodes on gut health, hormones, and getting to the root cause of how you feel. You’ll find every episode, free resources, and my book Hormone Havoc at hormonehavoc.com.

References

Baker JM, Al-Nakkash L, Herbst-Kralovetz MM. Estrogen-gut microbiome axis: Physiological and clinical implications. Maturitas. 2017;103:45-53. PubMed

Carabotti M, Scirocco A, Maselli MA, Severi C. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Ann Gastroenterol. 2015;28(2):203-209. PubMed

DeNeui T, host. [Episode title] with Dr. Cassie Smith, MD. The Dr. Terri Show. [Release date]. [LINK]

DeNeui T. (2023). Hormone Havoc: Dispelling the Myths & Misconceptions About Hormones in Women and Men. Holland Robinson Publishing.

Ervin SM, Li H, Lim L, et al. Gut microbial beta-glucuronidases reactivate estrogens as components of the estrobolome that reactivate estrogens. J Biol Chem. 2019;294(49):18586-18599.

Kwa M, Plottel CS, Blaser MJ, Adams S. The intestinal microbiome and estrogen receptor-positive female breast cancer. J Natl Cancer Inst. 2016;108(8):djw029. PubMed

Frequently Asked Questions About Gut Health and Hormones

Can poor gut health cause hormonal imbalance?

It can contribute. An imbalanced microbiome can affect estrogen clearance, insulin, cortisol, and inflammation, all of which influence hormonal balance. Gut health is rarely the only factor, so a full evaluation of thyroid, adrenal, and sex hormones is worth pursuing alongside it.

Does gut health affect estrogen levels?

Yes. When harmful bacteria overgrow, they increase beta-glucuronidase, an enzyme that lets used estrogen be reabsorbed instead of eliminated. The relationship runs both ways, since estrogen also affects gut motility and the makeup of the microbiome.

Can hormone changes affect my gut?

Absolutely. Declining estrogen in menopause can change gut motility and the microbiome, and losing progesterone in your 40s may set the stage for leaky gut and bacterial overgrowth.

Can improved gut health help with PMS?

It may help some women. Regular bowel movements, steadier blood sugar, and lower inflammation can ease bloating and mood symptoms for some people. Research on gut health and PMS specifically is limited, so results vary.

How long does it take to improve gut health?

Your gut can start responding to diet changes within weeks, but lasting healing usually takes a few months of consistency. In my experience, healing a damaged gut lining can take up to 12 weeks.

What foods support gut health and hormone balance?

Aim for variety: colorful vegetables, berries, nuts, seeds, and other fiber-rich whole foods, plus fermented foods like kefir and sauerkraut. Cruciferous vegetables and omega-3 rich fish round out a plate that supports both your gut and you