Your Guide to Gut Health

Most people don’t think twice about their gut, but it’s tremendously important. Your digestive tract contains 38 trillion different organisms called the “microbiome” and comprises 70% of your immune system. It also produces 30 different neurotransmitters, which keep your gut in constant communication with your brain. This means that the quality of your microbiome directly influences your brain, and that your brain influences your gut microbiome. A healthy microbiome produces serotonin (the “feel good” molecule), dopamine (which is important in motivation), and the calming neurotransmitter GABA. So a good gut means a good mood, and vice versa.

Besides the gut-brain communication axis, a robust microbiome helps us in a variety of ways. It protects us from infection, prevents autoimmune conditions, and lowers inflammatory skin conditions like acne and psoriasis. Long-term, a healthy gut has been associated with a lower risk of type 2 diabetes, cardiovascular diseases, and even cancer. If that’s not enough, studies have shown that your microbiome affects your ability to lose weight. People who have failed weight loss programs despite dietary restriction have been able to finally lose weight when they have received gut bacteria from a thin person with a healthy microbiome.

The health of our microbiome starts at the moment of birth. Babies’ digestive tracts don’t contain bacteria until they pass through the birth canal and become colonized with mom’s natural bacteria. This sets the course for a healthy microbiome with lots of different types of bacterial strains, and it’s the reason why babies born vaginally have stronger microbiomes than babies born by cesarean section. Similarly, breast fed infants have more diverse gut bacteria than bottle fed infants. Unfortunately, kids who have had antibiotic exposure early in life tend to have fewer species of the good gut bacteria that protect us. This is not to say that we’re doomed if we haven’t had exposure to much good bacteria from childhood, but it can be a risk factor for gut issues later in life.

So how exactly does your microbiome protect you? When your gut is functioning optimally, the good bacteria in your microbiome produce short-chain fatty acids such as butyrate, which helps protect the gut lining. This keeps things like bad bacteria and food proteins from crossing into your body. When the gut lining is damaged, however, the “tight junctions” between the gut cells open up, and all the proteins and molecules that are normally kept out are able to cross into your body. When these foreign proteins get into your body, your immune system kicks in to neutralize the invaders, and inflammation ensues. Some things that can damage your gut lining include toxins (like alcohol), stress, and sugar-laden foods, which can feed the bad bacteria in our gut. When the bad bacteria overgrow the good bacteria, there isn’t enough butyrate to protect the gut lining. This is called “dysbiosis.”

Leaky gut, or damage to the gut wall lining, can partially explain why the incidence of autoimmunity is on the rise. With a damaged gut lining, food proteins can get into our body and react with our immune systems. One of these proteins is gluten, which is found in wheat. The problem with gluten is that it’s an abnormally large protein, which is more likely to be recognized by our bodies as foreign, and part of the gluten protein can resemble our body’s own tissue. Molecular mimicry is when the immune system picks up a food protein (like gluten), and confuses it with our body’s own tissue (like thyroid tissue). The end result is an autoimmune condition (like Hashimoto’s thyroiditis). It doesn’t just happen with gluten and thyroid tissue. There are more than 70 autoimmune conditions, and each can be caused by many different things. Likewise, a single food reaction can have many different downstream effects. But due to the highly processed nature of the grains we consume in America, which alters its structure, gluten intolerance is becoming more prevalent.

Fortunately, there are several things we can do to keep our guts healthy. The three main goals of gut health are: (1) support your good bacteria (2) minimize your bad bacteria, and (3) heal your gut lining. The most important thing you can do to support your good bacteria is to eat soluble fiber in the form of plants and vegetables. This gives the good bacteria in your microbiome the fuel to thrive and to keep producing the short-chain fatty acids that protect us. This good soluble fiber is called “prebiotics,’ and every plant has prebiotic fiber. Since there are so many diverse strains of good bacteria in our gut, it’s best to rotate a wide variety of vegetables in your diet on a regular basis.

Probiotics are the actual live bacteria strains that have been shown to be beneficial to your body. The best way to get probiotics is through fermented foods, such as yogurt, kimchi, sauerkraut, and kefir. Probiotic supplements are also available with a wide variety of beneficial bacteria strains. There are also particular strains you can take to help treat specific conditions such as depression. Some practitioners are even able to determine which types of bacteria a patient is lacking, and give those strains individually. The world of personalized probiotics is still in its infancy, but there is more work to come in this space.

For the majority of us, eating a high-fiber diet and fermented foods is sufficient. But for those seeking to restore microbiome health after stress, travel, or a course of antibiotics, additional probiotic supplements can help. As a general recommendation, it’s best to choose an over-the-counter probiotic supplement with the widest variety of the bacteria strains and the greatest concentration of those strains (the most CFUs, or colony forming units). Make sure your supplement is shelf-stable, as many probiotics require refrigeration to be effective. Finally, always take your probiotics on an empty stomach, as the bacteria must survive the acidity of the stomach (which food will make worse) and travel the length of your digestive system to be effective.

If prebiotics and probiotics aren’t enough, talk to your gastroenterologist or functional medicine practitioner about an elimination diet. An elimination diet is the gold standard for the diagnosis and treatment of gut disorders. The goal is to identify which foods are triggering your symptoms. Basically, it’s a temporary anti-inflammatory diet. You eliminate foods such as processed sugar, grains, dairy, eggs, nuts, seeds, alcohol, and caffeine for several weeks. Then, under the supervision of your practitioner, you reintroduce the foods slowly, one at a time, to see which ones trigger your symptoms. Elimination diets are not calorie-restricted, so you can eat as many anti-inflammatory foods as you’d like, including organic meat, fish and poultry, ghee, olive oil, avocado oil, coconut oil, vegetables, fruit, and natural sweeteners such as maple syrup. It’s not meant to be a long-term solution, but it can be a life-changing, personalized exploration into what’s making you sick.

Granted, this topic is extensive. For more information on gut health and what you can do to optimize yours, I recommend the book Fiber Fueled by Dr. Will Bulsiewicz. “Dr. B” is a gastroenterologist and probably the most famous gut health champion. He provided a comprehensive overview of the importance of the microbiome as a guest on the Rich Roll podcast (episode 538). I would also recommend the Huberman Lab podcast on how to enhance your gut microbiome for brain and overall health (February 28, 2022) as a deep dive into the gut-brain axis.

How has learning about your microbiome changed your diet, your life, and your health? Let me know in the comments below. As always, thanks for reading!