It's an exciting time to be in nutrition! Imagine if doctors came out and said they had discovered a new organ in the body. That's essentially what the research on microbiomes has found.
What's a Microbiome?
Microbiomes are an outline of the genes of all the microbes that inhabit our bodies. In the gut, microbes perform functions such as fermenting carbohydrates, creating vitamins, and altering toxins. Now that the genes of all these microbes have been mapped, researchers have discovered that although the bacteria in the gut vary from person to person, at a genetic level, they all behave the same. Some scientists have said that working together these bacteria may perform more metabolic functions then even the liver!
The "Hygiene Hypothesis" - Mircrobes and Your Health
Initially created from our birth environment, our microbiomes are fairly well-formed by our first birthday. Our gastrointestinal tracts are initially populated with the microbes from the birth canal, the hospital, breast milk, or formula. The so-called "hygiene hypothesis" speculates that cultures that limit exposures to environmental microbes through processes like antibiotic treatment of animals, pasteurization, and refrigeration may cause incomplete development of microbiomes. These partial microbiomes are thought to be linked to the increased incidence of allergies and asthma. After the first year, our microbiomes are further impacted by stress, antibiotics, and diet. Because these microbes are involved in so many metabolic operations in our bodies, small changes can have a profound effect on our health, even causing disease.
Linking microbiomes to disease is such a new area of study that it's not yet clear how far reaching the implications are. It's commonly understood that after antibiotic therapy, probiotics are helpful in restoring gut flora. Apart from this therapeutic effect, there are few definitive relationships of the gut microbiome and overall health.
The Gut Microbiome's Link to Obesity
This is a science in its infancy. There are soundly based theories out there suggesting that the gut microbiome may have a causal effect on obesity. It's thought that the diverse microbiomes contain individual flora that use calories very differently. Those microbiomes with bacteria that use less energy will lead to increased calories absorbed. Persons with this type of microbiome will be at increased risk for obesity. This is only the beginning of the link between the gut flora and obesity. What if we could alter the microbiome to contain the microbes that helped keep us fit? The science spirals off into many more fascinating mechanisms that impact weight. Which ones are important in the current obesity epidemic is still to be determined.
There are just as many fascinating theories out there about the relationship of our gut microbiome and cancer, diabetes, neurological disorders, inflammatory bowel disease, even autism. The research has just begun. As understanding grows deeper, we move towards a new front in healthcare. Stay tuned for personalized medicine based on not just your genetic make-up, but the genetics of the trillions of microbes that call you home.
Jennifer Webb, MS, RD, CNSC is a practicing dietitian and freelance writer based out of Southern California. She has been practicing medical nutrition therapy for the past five years. Prior to her career in nutrition, she received a degree in early childhood development. She has combined her two passions, nutrition and family, into a career educating people about the impact food can have on health across the lifespan. She is currently a dietitian at a top children's hospital and runs a private practice. Her private practice specializes in family nutrition therapy, a technique that focuses on changing family habits to lead them to lifelong healthy lifestyles. Contact Jennifer at email@example.com.