Did you know that good health depends on microbial diversity in your gut? The microbes that make your digestive tract their home play a key role in every aspect of your health. Your relationship with those organisms is a codependent one - you provide a dark, temperature-regulated home that has a constant food supply, and in exchange the microbes regulate every metabolic process in your body including things like immune function, blood pressure, fat storage, hormone function and blood sugar regulation.
Given that your microbes have such an important role, understanding microbial diversity in relationship to disease has been an area of focus in research in recent years. One area of research has looked at mapping the diversity of traditional societies, and comparing that to modern societies. Traditional hunter-gatherer societies have been shown to have a greater diversity than city dwellers. Sadly, with urbanization, we have lost some of that diversity (Source).
Many researchers have speculated that this loss of diversity plays a role in our modern health problems. When we start to compare the gut microbial community of healthy individuals with those of people suffering from chronic conditions such as autoimmune and neurological conditions, we see clear measurable differences. If you suffer from multiple sclerosis then you likely have reduced Clostridia clusters XIVa and IV (Source), or if you have been diagnosed with Parkinson's then we know that your gut microbes differ from those of healthy individuals (Source). To find out if your health condition has been researched, do a search with the name of your diagnosis and the word microbiome.
Unfortunately these studies only show us the imbalances that exist in gut microbes with disease, but don't give us any indication as to whether or not a loss of diversity has contributed to the disease. In order to understand how loss of diversity has affected us, all we can do is go back to the few remaining societies that still have diversity, and look at the kinds of health conditions these groups of people suffer from, and compare them to Westernized or urbanized societies. Research into this area, is still in the early stages, but warrants further exploration.
How To Get Gut Microbial Diversity
Jeff Leach, who cofounded the American Gut Project, has studied the Hadza population in Africa, specifically in relation to their gut microbiomes. Jeff believes that high fiber content is one of the contributing factors to the Hadza's microbial diversity (Source).
Another of the biggest contributing factors to diversity is your environment. The greater the diversity of organisms in your environment, the greater the diversity in your gut. Modern homes and buildings don't provide ideal environments for diversity (Source).
So these factors can provide two important steps to increasing your gut microbial diversity:
1) Eat a diet rich in plant-based fiber. Follow the Hudza example and eat a diet that consists mostly of vegetables and fruit. I usually recommend that 3/4 of any meal should be vegetables or fruit.
2) Spend time outdoors in a variety of settings. Here in Calgary we have the mountains at our doorstep. Closer to home, we have great city parks. Even closer is your own backyard. Being outdoors exposes you to a greater variety of microbes. Open your windows regularly! It's a simple step that will change the diversity inside your home.
Happy, Healthy Eating (and diversifying)!