Maintaining a strong microbiome is essential to our immune, hormonal, and metabolic health, so understanding how to improve it is very important.
What is Microbiome?
A microbiome is the interrelated community of bacteria, viruses, fungi, and archaea present on and within the human body, which can have both positive and negative effects. Most experts believe that human beings possess anywhere between 30 and 300 trillion microbes, more than 1/3 of which reside in the gut. When people talk about the microbiome of humans, the microflora environment of the gut is typically what they are referring to, but these microbes reside in all parts of our body, including on the surface of the skin. 
While many people think of bacteria, viruses, and fungi as bad things, there are actually hundreds of billions of beneficial bacteria that can aid in digestion and the balance of pH in the body, as well as metabolic activities and the production of hormones, among others. Having a properly balanced and healthy microbiome can aid in heart health, the prevention of diabetes, dementia, longevity, and cancer.   
If you want to alter your diet to boost or balance your microbiome, you should add certain foods, such as fruits, probiotic foods, and dark chocolate, as well as avoid others.
Foods to Eat
If you want to boost your microbiome, you want to eat natural foods that are high in antioxidants, fiber, minerals, and vitamins, including many of the following.
- Probiotic Foods (tempeh, kimchi, yogurt, sauerkraut, miso, and kombucha, etc.)
- Healthy Fats (avocados, walnuts, olives, nuts, salmon, ground flaxseed, etc.)
- Dark Chocolate
Foods to Avoid
Certain foods can also do clear damage to your microbiome, primarily because they cause an increase in inflammation.
- Processed and refined foods
- Trans fats
- Pasteurized dairy products
- Refined vegetable oils (soybean, corn and canola oils)
- Added sugars (junk food, candy, sweets, canned foods, condiments, etc.)
How Can You Establish a Strong Microbiome?
Establishing and maintaining a strong human microbiome can be achieved by avoiding antibiotics, supplementing, and reducing stress levels, among others.
One of the major threats to overall health is chronic stress, as this can lead to inflammation throughout the body, an imbalanced nervous system, poor digestion, unhealthy sleep habits, and a higher risk of chronic diseases. Finding ways to relax and calm your body/mind is an excellent way to protect your microbiome. 
Antibiotics may be required for certain aggressive viruses, but overusing antibiotics can kill off both the good and bad microbes in your gut, leaving you more vulnerable to future pathogenic attacks. 
Spend Time Outside
Exposing yourself to microbes by interacting with nature can give you a diverse and flexible microbiome that is more capable of defending you against potential infections.
If you can’t alter your microflora enough through your diet, some people use supplements, such as magnesium, vitamin D, and fish oil, all of which can protect and stimulate the health of your gut. 
Prebiotics and Probiotics
Prebiotics are foods that are well known to strengthen your immune system, while probiotics are foods that contain live bacteria that are intended to stimulate or improve overall gut health. Taking a proper combination of these foods or supplements can go a long way to protecting and maintaining your microbiome.