Nuture Your Gut & Improve Your Heart Health
I hadn’t learned anything in medical school about how heart disease affects the digestive system and vice versa, so with little else to fall back on, I gave the patient a common-sense recommendation: Stay away from fatty foods and cabbage. He did and his symptoms improved enormously.
You may also know your gut plays a central role in immune function. About 70% of your immune system is housed in the intestinal lining, which is in direct contact with gut microbes—and there’s extensive crosstalk between the two. For instance, the gut microbiota helps “train” the immune system, thereby reducing allergies and autoimmune diseases.
But what you may not realize is the gut microbiota also generates a number of important substances that are utilized throughout your body. Some gut bacteria synthesize vitamin K and B vitamins. Others produce enzymes, inflammatory cytokines, and short-chain fatty acids such as butyrate that communicate and interact with the nervous, vascular, and endocrine systems—directly affecting your heart health.
• Cholesterol: Certain gut bacteria can actually transform cholesterol into another substance called coprostanol, resulting in lower blood cholesterol levels. Better yet, strains of Lactobacillus plantarum that are included in some probiotic supplements have been demonstrated to reduce total cholesterol. These probiotics also lowered triglycerides and oxidized LDL and increased protective HDL cholesterol.
• Hypertension: Researchers have found distinct alterations in the microbiota of individuals with hypertension. A reduction in butyrate-producing bacteria, for example, has been linked with elevated blood pressure. Other research suggests that a high sodium intake raises blood pressure in part by its adverse effects on the gut microbiota.
• Inflammation: A major risk factor for many chronic diseases, inflammation can be triggered by imbalances that enable pro-inflammatory microbes to gain the upper hand. Conversely, studies have shown that some bacteria, including those that produce short chain fatty acids, have anti-inflammatory properties.
• Obesity: Because your gut microbiota influences your metabolism, energy expenditure, and even your appetite and food cravings, it helps determine if you are overweight. Obese individuals tend to have less microbial diversity and greater concentrations of certain bacterial species, compared to lean people. Plus, a number of studies have linked obesity with the use of antibiotics, which significantly alter the microbiota.
• Diabetes: The gut microbiota also plays a role in insulin signaling and blood sugar control. A recent review study in an online Lancet journal identified bacterial species from the genus Bifidobacterium that appear to be protective against type 2 diabetes—and other types that are more abundant in individuals with diabetes. This, along with its effects on weight and inflammation, underscores the association between the gut microbiota, diabetes, and its complications, which include heart disease.
Among the most significant threats are antibiotics, which indiscriminately mow down all bacteria, both good and bad, and seriously alter the gut microbiota. According to the CDC, pharmacies dispense more than 270 million antibiotic courses every year! To add insult to injury, at least 30% of them are completely unnecessary, and another 20% are used inappropriately.
Additional threats include antibiotic residues in meat and other foods, chlorine in tap water, sugars, food additives, and stomach acid-reducing proton pump inhibitors. All of these significantly disrupt the balance and diversity of your gut bacteria.
• Take probiotics. The benefits of these supplements, which contain billions of beneficial bacteria, for numerous conditions are supported by a growing body of research. Look for a product from a reliable manufacturer that contains a minimum of 12 billion CFUs of various strains of Lactobacillus, Bifidobacteria, and other supportive species.
• Eat more fiber. Fiber of all kinds is great, and I heartily recommend eating lots of fiber-rich plant foods. But make sure you include prebiotics, a specific type of fiber that encourages the growth of beneficial gut bacteria. Prebiotic fibers are broken down by gut microbes in a fermentation process that results in the production of short chain fatty acids, vitamins, and other important substances. Aim for at least 25–30 g of fiber a day—and don’t forget to include onions, garlic, oat, barley, flaxseed, and other sources of prebiotics.
• Cut out sugars and food additives. Sugars and refined carbohydrates contribute to the overgrowth of less desirable microbes and imbalances in the gut microbiota. Artificial sweeteners and other food additives such as emulsifiers, which are used in many processed foods to improve texture and extend shelf life, also adversely affect beneficial bacteria. • Clean up your diet. Try to eat antibiotic-free meat, poultry, and eggs. Avoid GMOs, as they may contain traces of glyphosate, an herbicide that disrupts the gut microbiota.
• Include fermented foods. Yogurt, miso, and unpasteurized sauerkraut, kimchi, and other fermented foods that contain live and active cultures help repopulate your gut with health-enhancing bacteria.
• Drink filtered water. Chlorine is added to municipal water supplies to kill infectious organisms, but it can also take a toll on your gut microbes. A home water filtration system is, over time, the most economical way to go. • Be aware of drug effects. Never take an antibiotic unless it is absolutely essential, and look for safer alternatives to Prilosec, Prevacid, and other proton pump inhibitors. Recent research suggests that metformin, SSRI antidepressants, and laxatives also change gut microbial composition and function.
How a Healthy Gut Affects Your Heart
In the last decade or so, we’ve witnessed an explosion of research surfacing about the gut microbiome and how it can influence other systems in the body. Since my father, Dr. Stephen Sinatra, specializes in integrative cardiology, I am fascinated with any research that connects gut health with cardiovascular health. How can it be that the health of the gut can influence the health of the heart and blood vessels?
I think we can all agree that diet certainly has an effect on the cardiovascular system. We know from many studies that those populations who eat foods similar to a Mediterranean diet have superior heart health. We also know that eating foods loaded with sugar, processed foods, and bad fats (trans fats, oxidized fats, etc.) can increase your risk of diabetes, obesity, and cardiovascular disease. Is it the foods themselves, or the health of the gut microbiome, that leads to these health outcomes? I think the answer is both.
In regard to cardiovascular health, studies show that an imbalance in gut flora, or dysbiosis, has been linked to certain cardiovascular pathologies including:
• Heart failure
• Kidney disease
• Type II Diabetes
In fact, in a 2018 study in the Journal Digestive Diseases and Sciences, researchers followed patients who had SIBO (small intestinal bacterial overgrowth), a form of dysbiosis, and looked at the development of coronary artery disease. They found that having SIBO correlated with the following results:
• Higher frequency of CAD (coronary artery disease)
• Higher frequency of diabetes
• Higher frequency of chronic kidney disease
• Higher use of ACE inhibitors (a medication used to treat blood pressure)
• Higher use of statins (a class of medication used to treat high cholesterol)
Another study showed that having SIBO lead to an increase in arterial stiffness. We know that SIBO can affect the absorption of certain vitamins like Vitamin K2, and we also know that SIBO can lead to systemic inflammation.
Without going into too much detail about these results, we can conclude that having SIBO may increase the risk for certain pathologies like CAD. This is more evidence that anyone with heart disease should make sure gut health is in good shape.
I think that that this meta-analysis is a very important study for physicians, including cardiologists, to read as it shows that taking a probiotic can lower total cholesterol. Yes, the cholesterol-lowering effect is relatively small compared to medication, but at least it’s a good place to start with minimal risk.
Instead of immediately reaching for the prescription pad, which surely will include a statin medication, I wish physicians would first educate patients about the importance of healthy foods and probiotics. Including these in the diet may help reduce cholesterol levels and lead to more improved cardiovascular health outcomes.
• Improve blood sugar and weight in diabetics
• Help regulate blood pressure
• Help decrease inflammation
• Modulate the immune system
If SCFAs are good for the cardiovascular system, does this mean that you immediately load up on fiber supplements? No, I don’t think so. To me these findings suggest that choosing a diet rich in fruits and vegetables over the long term is a good idea if you want to improve your cardiovascular health.
If you introduce too much fiber too quickly into your diet, you may experience gas and bloating, which can be very uncomfortable. I suggest slowly introducing the following fiber rich prebiotic foods into your diet:
In summary, I am so excited to learn more about research linking gut health to cardiovascular health. For years we’ve been aware of the classic cardiovascular risk factors like obesity, diabetes, smoking, hypertension, and dyslipidemia. Now we know that certain GI conditions like dysbiosis may also be a risk factor, or that probiotics and fiber containing foods can be protective in the fight against heart disease.