Gut Health & Anxiety: How The Two Are Linked

Are you ever anxious about something so much that you get a stomachache? Maybe you have to give a big speech at work or school (you hate public speaking) or are nervous about a first date (you have social anxiety). Well, it turns out that gut health and anxiety are linked. According to Harvard Health Publishing, the two truly go hand-in-hand. This is because the gastrointestinal (GI) tract is affected by your emotions — both good and bad. And your emotions can also be affected by your gastrointestinal tract. If you find yourself with an upset stomach and know it’s not from being ill or from food, it’s likely due to how you’re feeling, whether it’s from stress, excitement, or something else.

Christine Randazzo Kirschner, registered dietitian, nutritionist, and co-founder of Amenta Nutrition, agrees that the two are linked. “We know from the literature that about 95% of serotonin is produced in the gut,” she tells TZR in an email. “What this tells us is that the food we eat, that feeds our beneficial bacteria, impacts the amount of serotonin that is available in our bodies. This influences our moods, which can include anxiety and GI activity.” She says gut microbes produce metabolites (short-chain fatty acids, SCFAs) that the brain uses to regulate basic physiological processes, as well as mental processes (including learning, memory, and mood). “These SCFAs promote colonic serotonin production,” she explains. “Short-chain fatty acids are the result of the metabolism of the beneficial gut microbes/bacteria that live in our colon, and some of them are involved in the making of serotonin.”

What Role Anxiety Plays In Gut Health

For an inside look on the role anxiety plays when it comes to gut health, Randazzo Kirschner says the vagus nerve runs from the brainstem to the abdomen, carrying signals from the brain to the digestive system (and vice-versa). “It is the link between the central nervous system (CNS), which is housed in our brain, and the enteric nervous system (ENS), those nerves that line the digestive tract. Essentially, it is a two-way highway between ‘brain’ town and ‘gut’ town.” It impacts many things, including: digestion, visceral hypersensitivity, and other hormonal processes. “From what we know from the literature thus far, having anxiety alone does not negatively influence the microbiome (gut health),” she says. “But what anxiety can do is exacerbate symptoms related to the gastrointestinal tract.”

For example, if you have an important presentation coming up at work and you're nervous and stressed, you may feel nauseous, or a sense of urgency, that makes you run to the bathroom, she says. Or, for someone who has irritable bowel syndrome (IBS), oftentimes they are unsure which foods are causing their symptoms, like bloating or abdominal pain. “This can lead to a fear of foods, because this person is so afraid of being in pain,” she adds. “This fear can then exacerbate those symptoms, causing them to suffer even more.”

Gut Health Dietician Naria Le Mire adds that it’s important to understand that we all have both beneficial and non-beneficial bacteria in our gut microbiome. “This unique ecosystem requires an equilibrium that helps not only the gut microbiota (AKA gut health) flourish, but also benefits one’s health via prevention of illnesses and infections,” she tells TZR. “When the equilibrium is off (possibly related to chronic stress), it can result in gut dysbiosis (imbalance in the gut), which increases the risk of illnesses and infections.”

So while our bodies release certain hormones to combat everyday stress, if someone’s experiencing chronic stress, it can create imbalances. “Basically, their body’s ability to ‘combat’ stress becomes fatigued,” says Le Mire. “Overactivation of stress-related hormones can then impair one’s immune system and negatively affect their gut health.” Lyndsay Gutierrez, health educator and founder of Nourish, seconds that and says anxiety (and stress in general) impacts the gut by changing the way our body manages the signals. “Most people know about ‘fight-or-flight’ response (our sympathetic nervous system), but few know its opposite: "rest and digest" (parasympathetic nervous system). “When we stay in fight-or-flight all the time, our body is planning to run from a (metaphorical) tiger, so it sends all of its energy and focus into our muscles and senses to keep you alive,” she tells TZR in an email. “So even if you ate nutritious meals, your body isn't absorbing as much as it could be, or digesting like it should. Not to mention that you're less likely to eat healthy meals when you're stressed or anxious to begin with. These conditions are also not ideal for our microbes and don't support healthy balance.”

Ryan Andrews, principal nutritionist and adviser for Precision Nutrition, says to think of the body as an ecosystem. “By this, I mean that all body systems work together to coordinate overall health,” he tells TZR in an email. “Our digestive system is one of the systems that influences the sensitivity and responsiveness of the entire body, including our brain and mental health.” However, he also says it's important to keep in mind that mental health is influenced by many factors, and mental illness may persist independently of nutrition and gut health. Outside of markers measured in a lab, he notes that one of the most telling signs that the gut and brain are linked would be the noticeable sensations many of us get in our gut in response to strong emotions. “Receiving anxiety-provoking news can alter our hunger cues, and can even lead to nausea and diarrhea for some folks,” he says.

How You Can Better Manage Your Gut-Brain Connection

There are many ways to reduce anxiety — from talk therapy to cognitive behavioral therapy (CBT) to acupuncture (and more). But being mindful of what you eat also plays a pivotal role. “As a registered dietitian, my number-one priority is to make sure my patients are consuming the most nutritionally adequate, least restrictive eating pattern that does not cause belly discomfort,” Randazzo Kirschner says. “Thus, figuring out which foods, if any, are causing symptoms is key — because you should not live in fear. It is vital to receive help from someone who is qualified, like a registered dietitian who specializes in gastrointestinal nutrition or a gastroenterologist.” She notes that what you should not do is rely on unvalidated food sensitivity testing that is not evidence-based. “Too often, we see patients who are told they have a food sensitivity or allergy, when in fact they don't,” she says. “This can lead to unnecessary food restrictions (and, by the way, they have been eating these foods with no symptoms their whole lives). So be aware of expensive, unnecessary testing.”

Andrews says that how someone goes about healing their gut is really influenced by what caused gut irregularity in the first place. “Maybe it was due to a medication, dietary change, or an illness,” he says. “Once this has been identified, a protocol for healing can be outlined and implemented. However, generally speaking, eating a wide variety of plant foods, avoiding unnecessary antibiotics, and breastfeeding as an infant are three of the main ways to support the development of a healthy gut (although many other factors also come into play throughout our lives).” Randazzo Kirschner adds that another great tool to have in your back pocket in a moment of anxiety is diaphragmatic breathing. “Taking as little as five minutes to do it can help reduce stress hormones, lower your heart rate and pressure, and decrease muscle tension — and it activates the parasympathetic system (the relaxation response),” she explains. “It can also calm the digestive tract and ease moments of panic.”

Gutierrez says her favorite way to get less anxious is to start practicing gratitude before meals. “Take that moment to take a few breaths and switch out of fight-or-flight before you eat,” she explains. “By convincing your body you aren't being chased by a tiger, so to speak, it sends the energy back into your digestion, as well as allows you to sleep better and have a better sex drive — all things that get pushed to the end of the line when you're stressed or anxious. Gratitude and stress are opposite brain patterns, so the practice is good on many levels.”

Once you're practicing that, she says you can start to improve your gut health. “Adding traditionally fermented foods — like real sauerkraut or kimchi (from the refrigerated section, not a can), kombucha, and even yogurt will help improve the population of beneficial bacteria,” she says. “And don't neglect the gut lining: ‘leaky gut’ (or ‘increased intestinal permeability’ as you'll find it referred to in the research), is at the heart of many health and gut problems,” she says. “Cutting out the foods that cause damage, such as fast food and highly processed or commercial foods, and adding in healing foods, like bone broth and fermented foods, will support the body's ability to heal.”

Le Mire says that, fortunately, you can be proactive and have a healthy gut, and can start by practicing mindful stress management techniques. “Oftentimes, when I begin working with my clients, I inquire about their stress and anxiety levels, because I know the massive impact it can have on their gut health,” she says. “Simple changes in one's daily routine to reduce anxiety and stress can include taking mindful breaks and walking outside and to get fresh air, taking deep and slow breaths, or adopting new habits (personally, I began cycling, and I love it). As a dietitian and nutrition coach, a massive part of my practice is to prevent chronic conditions, and therefore, focusing on gut health is vital.” She adds that you can't talk about health without mentioning the gut. “And apart from stress management, focusing on a variety of fruits/vegetables, whole grains, fiber intake, pre- and probiotics, healthy fats, and a minimally processed diet must also be considered,” she says. “In summary, happy gut, healthy life.”