Periods can affect all different parts of our bodies, and the gut is no exception. Digestive symptoms like bloating, constipation, and diarrhea are common before and during bleeding days. What’s going on in the body that might cause these symptoms to show up?
DN: Period poop is definitely a thing…and it’s not uncommon for digestive conditions like irritable bowel syndrome to feel worse at different times in your cycle. There are a few different reasons for this, including the natural flux of hormones during your cycle. Prostaglandins released by the uterus help initiate contractions that cause the uterine lining to shed but they can also influence the smooth muscle of the digestive tract, leading to diarrhea when levels are high.
As progesterone levels increase in the later part of your cycle, they can slow down the gut motility (movement of the gut) and cause bloating and constipation. Progesterone can also influence cravings and eating a lot of higher fat, lower fiber foods during your pre-bleeding days can alter your gut microbiome and elimination habits enough to notice the effects.
We hear a lot about the importance of a healthy microbiome in the news these days, and there always seems to be new research about all the ways it impacts our health. What exactly is the microbiome?
DN: Our digestive tracts aren’t just food processing machines; our gut lies at the intersection between digestion, nervous system function and immune health. A whopping 70% of our immune activity is located within and along our digestive tracts and yet somehow, we manage to live in harmony (usually!) with a few trillion or so bacteria, known as the gut microbiota. We often use the terms microbiome and microbiota interchangeably but the term microbiome refers to the trillions of microorganisms that call us home—the microbiota—plus their genetic material.
We always say period health is an extension of general health. What are some ways our microbiome affects our general health, and how might one go about improving the health of their microbiome?
DN: Research suggests that our gut bacteria are as important to our bodies as any of our other organs are; these tiny critters are in constant interaction with the immune and nervous systems and can have a big impact on our digestion. For example, bacteria-like organisms called methanogens can cause bloating and constipation when they overgrow. Having a strong and resilient microbiome can ensure that gut-wrecking bacteria don’t get a foothold and our gut barrier stays strong, minimizing inflammation. Our gut microbiota can even alter the production of neurotransmitters like serotonin, which is mostly made in the gut’s nervous system and not the brain.
We are learning so much about how our behaviors influence our microbiome: diet is major but stress and exercise also play an important role. Our modern, hyper-processed food system supplies plenty of fat and sugar to the detriment of high fiber plant foods, and the evidence suggests that this kind of dietary pattern contributes to an imbalanced microbiome. As much as you can, I recommend eating whole foods most often alongside regular movement and stress management.
The internet loves to blame gluten or lectins for digestive issues, but I typically caution against elimination diets when gut health goes awry. Sometimes, an evidence-based approach like the low FODMAP diet for IBS can be supportive in the short term. However, dietary restriction tends to breed further intolerance and it can make gut health worse.
We love that you’re a Registered Dietitian, which means you’re a food and nutrition expert who always follows the science. What are your favorite evidence-based ways to improve gut health via the diet?
DN: The number one thing you can do to create a healthy and resilient microbiome is to eat a wide variety of whole plant foods each and every day. Good bugs like plants! Plant foods contain what we call ‘microbe-accessible carbohydrates’ meaning that we can’t digest and absorb them, but our microbiota can! It goes way beyond dietary fiber—although fiber is important too—because there are also prebiotics, FODMAPs and resistant starches in plant foods that foster the growth of beneficial bugs. The evidence also suggests that polyphenols—naturally occurring plant chemicals—in plant foods boost the microbiome, too.
It’s important to work your way up to a plant-full life slowly; you’ve got to train your gut the same way you train your muscles at the gym. And don’t forget that all plants are good plants! Kale is great, but hemp hearts, wheat berries and even olives have their bacterial charms.
Back to those pesky digestive symptoms that can show up around menstruation: do you have any recommendations for natural remedies one could use to target things like bloating, constipation, or diarrhea?
DN: I’m a big psyllium fan—me and the grannies!—because it’s an excellent bowel regulator. It’s a low fermentation (less gas!) but highly soluble fibre so it helps to keep things hydrated, easing constipation, in addition to binding things up making it great for diarrhea. It’s super important to drink a ton of extra water when adding fibers like psyllium to the diet. And always start slow, particularly if you are constipated because adding fiber to a sluggish bowel can make you feel even more sluggish at first.
Enteric-coated peppermint oil is an anti-spasmodic, so it can ease crampy digestive pain and bloating. I also love ginger for that nauseous, overly full feeling. Ginger is prokinetic, meaning that it helps improve stomach emptying and it’s also a fantastic anti-inflammatory food.
