The Microbiome and Nutrition

Over the last decade or so, we’ve experienced a major cultural shift regarding health and wellness. After an explosion of research and scientific studies into the complex interactions between humans and the world around us, it seems that people now are more in tune with their bodies than ever before. One of the most interesting series of developments regarding our understanding of human physiology is the emergence of the microbiome—we have trillions and trillions of little critters living inside of us and helping make our lives easier and healthier. And many of your clients are likely coming to you with questions about their microbiome and gut health! 

What is the microbiome?

The microbiome is the collection of symbiotic microbes (mostly bacteria) living in and on your body. Most microbiome research focuses on the gut microbiome -- the bugs living within the digestive tract. In total, we are all made up of more bacterial cells than human cells, with some estimates leaving us outnumbered 10:1. Each person’s microbiome is unique, just like a fingerprint! A rapidly-developing field of research is looking at characterizing individual microbiome species assemblages and associating that diversity with disease susceptibility. 

Where does it come from?

Currently, the National Institutes of Health is hard at work supporting the Human Microbiome Project to try to understand the complex interactions between our microbiomes and our bodies.

The origins of the microbiome are varied and complex. We begin to acquire our microbiome at birth, so the route of delivery can play a major role. During a natural birth, a baby is exposed to bacteria in the birth canal that begin to establish the microbiome. There may be altered microbiomes in infants delivered via Cesarean section, though the long-term effects of this are still unclear. Early postnatal diet and environmental exposures also play a role in establishing the microbiome. Your immune system, which is normally tasked with distinguishing self from “non-self” invaders, learns to tolerate these bacteria, thereby facilitating symbiosis.

Why is it important?

The microbiome plays a number of critically important roles in our body. We rely on our gut microbiota to produce essential vitamins and amino acids that we cannot synthesize ourselves or acquire directly from food. Gut bacteria are also highly active metabolically and actually help to facilitate our digestive process. They help prevent infection by both stimulating the immune system and helping to out-compete harmful bacteria. The microbiome can be altered by diet, as well as environmental exposures to chemicals. Together with genetic factors, the health of the microbiome is one of a number of factors that modulates individual disease susceptibility. An imbalance in the microbiome, or any disruption in its function, is referred to as dysbiosis, and can cause or contribute to disease. There are far-reaching consequences of dysbiosis, as the microbiome interfaces with the immune and endocrine systems.

What can I do to promote a healthy microbiome?

We can take a number of steps to promote microbiome health. A number of over-the-counter probiotics are available. These are supplements that contain doses of bacteria that are important for the microbiome. Once in your system, the bacteria proliferate and re-establish your microbiome. Of course, if you or your clients have questions about supplement use, please consult your doctor. In addition, some common foods, like yogurt and kefir, contain bacterial cultures that also act as probiotics. 

What is your advice for clients who approach you with questions about microbiome and gut health? 

For further reading, we recommend: