Your gut is home to trillions of microbes, including bacteria, fungi, parasites, and viruses. While this may sound odd, all of these play a role in your health (for better or for worse). Thankfully, the majority are good and help support the delicate bacterial balance you need.

However, when this gut microbial harmony is disrupted, it can trigger a cascade of negative effects including inflammation and immune suppression, setting the stage for disease. Recent research has discovered a connection between gut microbial imbalance (called dysbiosis) and inflammatory bowel disease, rheumatoid arthritis, obesity, and cardiovascular disease. 

Let’s take a closer look at the gut microbiome and heart-stomach connection.

Gut Problems that Affect the Heart-Stomach Connection

An occasional bout of heartburn or constipation can signal that your gut microbiome is temporarily out of balance. However, when stomach problems persist, it may indicate gut dysbiosis that, when left unchecked, can negatively impact heart health.

Small Intestinal Bacterial Overgrowth

One way the stomach heart connection is demonstrated is through small intestinal bacterial overgrowth (SIBO), an imbalance in your gut microbiome that can lead to uncomfortable symptoms like bloating, gas, abdominal pain, and diarrhea. 

Research suggests a connection between SIBO and heart disease. In one 2018 study, researchers found that people with SIBO had a higher frequency of coronary artery disease (CAD). Specifically, CAD was detected in almost 80% of those with SIBO compared to 40% of those without SIBO. 

It’s important to note that patients with SIBO are often placed on long-term, restrictive diets like the low-FODMAP diet or an elemental diet to help manage the condition. However, these diets can cause a metabolic imbalance that can impact the health of your heart.

These restrictive diets can decrease n-butyrate, which is cardio-protective, and increase beta-glucuronidase which can negatively affect heart health. It’s important to work with an experienced dietitian when re-introducing new foods to help restore metabolic balance while managing symptoms.

Gastroesophageal Reflux Disease

There also appears to be a link between common GI symptoms like constipation, gastroesophageal reflux disease (GERD), and heart health. 

One large population-based cohort study found that constipation was associated with an increased risk of all cardiovascular outcomes in the short term and ischemic stroke after five years.

Another study found a strong link between GERD and coronary heart disease (CHD). Researchers found that a proton pump inhibitor (PPI) used for more than one year may also increase the risk of CHD.

The Impact of Imbalance

While much of the science has focused on the gut-brain axis, emerging research is beginning to notice a link between the gut-heart axis and its effect on cardiovascular disease. The studies surrounding this research have mainly focused on metabolites, the substances that your gut microbiota produces when food is broken down.

One metabolite is trimethylamine (TMA), produced when gut microbes feed on choline, a nutrient found in red meat, eggs, poultry, and fish. TMA gets converted to trimethylamine N-oxide (TMAO) in your liver. TMAO has been linked with an imbalanced gut microbiome, and science is looking closely at its connection to arterial plaque, and an increased risk of cardiovascular events like heart attack and stroke. 

One 2017 systematic review and meta‐analysis found that more TMAO in the blood was associated with an increased risk of major adverse cardiovascular events. Another 2017 review found that elevated blood levels of TMAO were associated with a 67% higher risk of major cardiovascular events, and a 91% higher risk of death from all causes.

Here are a few other examples of the heart-stomach connection: 

• High blood pressure: Gut dysbiosis can increase the production of pro-inflammatory compounds and reduce nitric oxide availability, impairing the ability of your blood vessels to relax and consequently raising blood pressure.
• Lower levels of HDL: An imbalanced gut microbiome may alter fat metabolism, decreasing the synthesis of HDL and promoting unhealthy lipid profiles.
• Acid reflux and dysmotility: Gut dysbiosis can alter gut-brain signaling, exacerbating motility issues and increasing susceptibility to acid reflux.

Fortunately, there are plenty of ways you can support the heart and stomach connection through everyday nutrition and lifestyle habits. 

1. Fiber

Diet plays a significant role in the composition of your gut microbiome, and what you feed your gut can affect heart health. 

One of the most critical nutrients for gut and heart health is fiber, found in foods like whole grains, avocados, lentils, chia seeds, and berries. Studies have found that fiber-rich diets can help reduce the risk of cardiovascular disease by lowering blood pressure and other cardiometabolic risk factors.

Moreover, when digested fiber is broken down to form short-chain fatty acids (SCFAs), like butyrate. Research shows that SCFAs promote a healthy gut microbiome and play a role in regulating blood pressure.

On the other hand, diets high in processed foods and sugar (and low in fiber) can encourage the growth of harmful gut microbes that are linked to cardiovascular disease and poor metabolic health. 

2. Probiotics

Probiotics are “friendly” gut bacteria and you can find them in fermented foods and supplements designed for gut health. They help maintain a balanced gut environment, reducing inflammation and promoting the production of SCFAs that support vascular health. 

Research suggests that certain probiotics can lower blood cholesterol levels by breaking down bile in the gut, preventing its reabsorption into the bloodstream. 

Incorporating probiotic-rich foods like yogurt, kefir, kimchi, tempeh, sauerkraut, and miso into your diet can nurture the heart stomach connection.

3. Hydration

Proper hydration supports digestion by ensuring smooth movement of food through the GI tract, preventing issues like constipation. Additionally, water helps regulate blood volume and supports circulation, easing the workload placed on your heart. 

Dehydration, on the other hand, can lead to thicker blood, increasing cardiovascular strain and potentially causing digestive discomfort. 

Your body is made up of around 60% water at any given time, but fluid levels fluctuate with things like sweating and using the restroom, and it’s important to replenish them. Sip on water from a reusable water bottle throughout the day and include hydrating foods in your diet, like fruits and vegetables, for heart and gut health.

4. Stress Management 

You’re likely familiar with the link between stress and heart health but there appears to be a connection between stress and gut health as well. Studies have shown that stress can alter the gut microbiome contributing to dysbiosis, immune dysregulation, and inflammation. 

Finding ways to manage stress including meditation, deep breathing techniques, and leaning on social support systems can positively impact your heart and gut health.

5. Exercise

While exercise can benefit heart health, it can also promote microbial diversity and increase healthy gut bacteria. 

Recent research suggests that exercise can reduce inflammation and positively influence the gut microbiota composition and the microbial metabolites produced in the gastrointestinal tract.

6. Hand Hygiene

Practicing good hand hygiene is a simple yet powerful way to support your stomach heart connection. Washing your hands regularly helps prevent the spread of harmful bacteria and viruses that can disrupt gut health and trigger inflammation. 

By minimizing the risk of infections through proper handwashing — especially before eating and after using the restroom — you protect your gut and reduce strain on your immune system, ultimately contributing to a healthier heart and stomach connection.

Strengthen Your Heart and Stomach Connection 

Caring for your gut is caring for your heart health, and vice versa. Nurturing this connection through your everyday nutrition and health habits is one of the most impactful things you can do for your body. 

As a cardiology dietitian, I take a whole-person approach with my clients to help ensure optimal heart health, including looking at your gut. Together, we can figure out how to adjust your diet pattern in a way that works for you and is effective at improving cardiovascular wellness. 

Click here to schedule a complementary 15-minute discovery call. 

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