- Written by Dr. Rand McClain Dr. Rand McClain
Most of us know that the bacteria in our gut help with our body’s digestion. But did you know that gut bacteria seemingly influence the health of everything from your brain and joints to your skin and heart health, too?
In recent years, researchers have been looking closely to find out just how many ways gut bacteria influence other areas of your health.
Two recently published studies are adding to this body of knowledge. These studies show a strong link between gut bacteria and the effects they may have on the aging process and heart health.
Read on to discover a quick review of what the gut microbiome actually is and what these two new studies have uncovered.
What is the Gut Microbiome, and How Does it Affect Health?
Trillions of microbes (bacteria, viruses, fungi, and other tiny organisms) exist inside your body. These microbes mainly live on your skin and in a pocket of your large intestine. Together, the microbes that live in your large intestine are known as the gut microbiome.
If the thought of “gut bacteria” is disturbing, know this: The bacteria in your gut help many of your body’s systems run smoothly. Sure, some “bad” species of bacteria can cause negative health conditions. But many “good” species support essential systems, like your immune health, brain health, and intestinal health.
Two characteristics of a healthy microbiome are:
• It is diverse, meaning that it contains a vast variety of bacteria species.
• It is stable, meaning the “good” and “bad” bacteria are balanced.
The bacteria in your gut play a huge role in your health. Scientists are continuously discovering new ways that your gut bacteria affect other systems in your body:
• Your immune system’s response to illness
• How your brain functions
• How your intestines function
• Your blood sugar
• Your body weight
And now, two new 2020 studies have uncovered two possible additional places where your gut bacteria affect your overall health. While these are both epidemiological studies, have some weaknesses in their design, and do not show clear cause and effect, the evidence appears to show that gut bacteria affect:
• How fast your body ages. Gut microbiome diversity (or lack thereof) has been linked to rapid signs of frailty and aging.
• Your risk of heart conditions. An unbalanced gut microbiome may contribute to heart health problems by producing a chemical called trimethylamine N-oxide (TMAO).
Your gut microbiome, like the rest of your body, progressively changes as you age. These changes may be caused by weakened immunity, medications, environment, lifestyle, or diet.
After age 60, the microbiome may decrease in diversity; lose beneficial microbes, like Lactobacillus and Bifidobacterium; and increase in “bad” populations, like enterobacteria.
In older people, these changes have been linked to rapid signs of frailty, weight loss, cognitive decline, and aging.
Can Diet Reconfigure Gut Bacteria and Help Slow Aging?
If changes in the microbiome can cause markers of aging, is there anything you can do to reverse it? One recent study says “yes.” This study, published in the journal Gut, found that diet may reconfigure gut bacteria in a way that promotes healthy aging.
The study specifically looked at the Mediterranean Diet (MedDiet). The MedDiet emphasizes vegetables, fruits, whole grains, olive oil, fish, and nuts. It includes less red meat and dairy than a typical American diet.
Researchers found that subjects who adhered to this diet for 12 months were able to alter the makeup of their microbiome for the better. These microbiome changes led to markers of lower frailty, supported cognitive health, and other benefits.
While the study specifically looked at the MedDiet, it has broader implications: Changing your diet may change your gut microbiome. And changing your gut microbiome may help promote healthier aging.
How Might Gut Bacteria Affect Heart Health?
The second study, published in The Journal of the American College of Cardiology, looked at a specific gut substance called trimethylamine N-oxide (TMAO). TMAO is produced in the gut when certain bacteria digest red meat.
Previous research has pointed to a strong short-term association between high levels of TMAO and heart health problems.
This new research was able to use data from a large longitudinal study to show how TMAO and cardiovascular health are linked in the long term. The data they looked at was collected over 10 years. The study found an apparent link between increased TMAO levels and heart health issues.
It also found the inverse: decreasing levels of TMAO may contribute to a reduced risk of heart conditions. And it is possible to decrease your body’s TMAO by altering your diet.
Both of these studies found that altering your diet can affect your gut’s microbiome, which in turn may positively affect aging and heart health.
Interested in using this new research to your advantage? There are plenty of changes you can make on your own to support your gut health.
Eat a diverse range of healthy foods. Again, one major takeaway from both of these recent studies is the connection between your diet and your gut bacteria. That is, your diet directly affects the strains of bacteria in your gut, and eating a diverse diet may lead to a diverse microbiome.
So, go ahead and change up the types of foods you eat. Your gut will thank you. But this doesn't mean eat whatever you want. Make sure you're getting plenty of whole, natural foods like fruits and vegetables. Unhealthy, processed foods can really take a toll on your gut microbiome and have the reverse effect.
Go heavy on high-fiber foods. Your body can’t actually digest fiber. But it can be digested by the millions of strains of bacteria in your gut that feed your microbiome.
So, one way to help keep your gut happy and healthy is to load up on high-fiber foods, such as:
• Fruits, like strawberries and raspberries
• Vegetables, like beets, broccoli, and Brussels sprouts
• Beans and legumes, like kidney beans, lentils, and chickpeas
• Grains, like oats and quinoa
• Nuts and seeds, like almonds and chia seeds
Eat fermented foods. Naturally fermented foods contain live microorganisms that may help strengthen your gut’s microbiome. A few good choices of fermented foods to add to your diet are: plain yogurt, kombucha, kefir, miso, tempeh, sauerkraut, and kimchi.
Limit artificial sweeteners. Some artificial sweeteners may stimulate the growth of unhealthy bacteria. This may change the composition or balance of your microbiome. If you intend to use an artificial sweetener, limited use of erythritol and stevia appear to have no negative impact on your gut microbiome or overall health.
Eat prebiotic foods. Prebiotic foods feed the healthy bacteria in your gut. A few ideas for prebiotic foods to add to your diet are: dandelion greens, chicory root, garlic, onions, asparagus, cocoa, and flaxseeds.
Take a probiotic supplement. Probiotics are live microorganisms that can change the composition of your microbiome. You can get probiotics from your diet, such as fermented foods. But many people opt for supplements if they find they aren’t getting the probiotics they need from diet alone.
Supplements can introduce important species of healthy bacteria, like Lactobacillus or Bifidobacterium.
Be sure to consult your doctor if you plan to change your diet or add supplements to your routine. Certain bacteria can affect your gut microbiome differently from others. Your healthcare provider can help give you specific recommendations.
Dr. Rand McClain, an expert in restorative and regenerative health, is the co-founder of LCR Health, a regenerative and sports-medicine clinic in Santa Monica, Calif.