The Human Microbiome: A Quick Introduction

What Is It? Why Does It Matter?

The human microbiome is a collection of trillions of microbes - such as bacteria, viruses, and fungi - that live in our digestive systems. Most of these microbes reside in the colon (large intestine), some of which we've had since birth, while others are introduced through food and environmental exposure. Supporting the health of these beneficial microbes is essential for maintaining our overall health.

A rendering of the human gut

When the microbiome is healthy and balanced, it performs crucial functions in our bodies: protecting against pathogens (harmful bacteria, viruses, etc.), synthesizing specific vitamins (such as B vitamins and Vitamin K), aiding in the breakdown and metabolism of polyphenols (powerful nutrients found in whole foods), converting amino acids (from protein) into neurotransmitters, and working closely with our immune system - 70% of which is found in the gut!

Beneficial Food Groups For a Healthy Microbiome

1. Dietary Fiber: Fiber is a powerful ally for the microbiome, often having an equal or greater effect than probiotics in improving the balance of intestinal microbes. Fiber serves as food for beneficial bacteria and supports the production of short-chain fatty acids, which are essential for creating new protective cells that line our colon. It also boosts immune function and promotes healthy bowel movements.

To increase your fiber intake, as tolerated, try adding whole grains, fruits (like berries and apples with the skin), leafy dark green vegetables (e.g. Swiss Chard or arugula) and alliums (such as onions, garlic, and leeks) to your meals.

Fiber-rich fruits and veggies

2. Polyphenols: Polyphenols are antioxidant-rich compounds found in plant foods like fruits, vegetables, herbs, spices, and teas. They support the microbiome by feeding our beneficial microbes, which in turn help to break down the polyphenols into usable forms for our bodies. Certain polyphenols, like those in turmeric, can even enhance the diversity of our gut microbes.

For a polyphenol boost, enjoy nuts and brightly-colored fruits and vegetables. Try an easy option like a handful of pecans and blueberries; experiment with new spices, or use old favorites like cinnamon in new ways to increase your overall intake.

3. Fermented foods: Fermented foods are packed with live cultures of healthy bacteria (like lactobacillus, found in sauerkraut and yogurt, and acetic acid bacteria found in kombucha). These microbes support digestion by helping to break down nutrients so our bodies can better absorb and utilize them.

Fermenting foods at home is a cost-effective way to increase probiotics, but you can also find probiotic-rich foods in grocery stores. Look for pickles, sauerkraut, kefir or kombucha in the refrigerated section (live probiotic cultures in food must be kept cold). If you are new to probiotics, start with small servings (about 1 tablespoon) and gradually increase as your system adjusts.

Examples of probiotic-rich foods

CAUTION: THE IMPACT OF STRESS

Chronic stress can wreak havoc on both our overall health and our gut microbiome. Elevated cortisol levels - the primary stress hormone released by our bodies in response to acute and chronic stress - can send distress signals to our gut. This can lead to increased inflammation, a reduction of microbial diversity, and intestinal permeability (a problem where the intestines can't properly regulate the types of cells that enter the bloodstream). These changes compromise the immune system, which is housed primarily in the gut. A weakened immune response can impact our health, which can cause even more stress, creating a harmful feedback loop.

Stress directly impacts your gut.

One simple, effective way to lower stress and support digestion is to slow down at mealtime. Put away screens, sit down to eat, and take a few deep breaths or practice gratitude before beginning your meal. Taking a pause from our stressors allows the body's resources to focus on effective digestion, which is central to maintaining a healthy gut microbiome.

Your gut health plays a key role in your overall well-being. By supporting a balanced microbiome with the right foods and reducing stress, you can improve your digestion and immune system function. If you're looking for personalized guidance to optimize your gut health, reach out today to learn how you can take the first step toward a healthier you.