Conservation Corner

Pauline Lee

A new frontier in human health has been opened up by the Human Microbiome Project, launched in 2008 by the National Institutes of Health. This initiative has begun cataloging the genetic material in bacteria that live in and on our bodies. Can you believe the bacteria population in each person outnumbers the human cells by at least three to one? Yes, our skin, guts, mouths and noses, along with every other body surface, are home to least 1,000 different types of microscopic bacteria that can add up to two and one-half pounds or more. These bacteria are collectively called our microbiome and the microbial community is known as our microbiota.

A man has 25,000 genes, but the more than 100 trillion bacteria living with him have over two million genes as an aggregate. The bacterial genes make it possible for us to assimilate dozens of essential nutrients critical to the health of our immune, digestive and nervous systems. Scientists are busily figuring out how beneficial microbiota help us to maintain health and well-being. They have already found a connection between the health and diversity of these bacteria with modern chronic diseases such as obesity, diabetes and autoimmune diseases.

Good health is accompanied by a stable, diverse microbiota in the gut. We depend on beneficial microbiota to break down indigestible fibers, build up our gut membrane, make products that nourish and regulate our body and help our immune system and our mood. If you are interested to find out the unique composition of your gut bacteria, you can participate in the American Gut Project by contacting to get instructions. It appears our modern health problems are linked with our modern diet of processed food. Since our beneficial microbiota flourish with a diet of natural and high fiber foods, our highly processed, overly sweetened, calorie-dense foods cannot maintain a stable, healthy microbiota. The typical daily western diet has roughly 10-15 grams of fiber. The Institute of Medicine recommends daily fiber intake of 25 grams for women, and of 38 grams for men. High fiber foods include whole grains, beans, vegetables, fruits and nuts.

At the latest estimate, nonpathogenic types of bacteria number around one million and the pathogenic types around 1,400, a ratio of nearly 700. Beneficial bacteria, just like the harmful bacteria, can be eliminated by antibiotics; they need to be replaced after being eliminated unintentionally. Our gut bacteria are naturally replenished through our contact with our surroundings, yet our modern antibacterial sanitation easily sterilizes many environments, wiping out beneficial bacteria which can be shared among people and pets. It will be decades before we understand the complex symbiotic relationships between our microbiota and us. But we can be healthier now by applying the preliminary scientific findings that will promote good bacteria in our gut: increase dietary fiber intake, minimize antibiotic use and use antibacterial soaps and wipes sparingly.