Did you know that you host ten times more bacteria in your gut than you have human cells? That’s 100 trillion bacteria!  All these bacteria, on the inside and outside of your body, are called your microbiome.


Your microbiome can be compared to a wild and diverse rainforest in that there are thousands of species, many of which are unknown.  There are at least 160 species (and counting) of bacteria in your intestines alone, making it the most diverse area of your body. Your microbiome begins to develop when you are born (maybe even before), from bacteria that you acquire from your mother, and continues to develop from contact with your environment and diet throughout your childhood and into adulthood. Research has found that the diversity and types of intestinal bacteria are related to an individual’s weight and risk for obesity.

Scientists conducted an experiment in human twins, comparing pairs of twins that were obese and to those that were thin. They found that the thin twins had a more diverse microbiome than the obese twins. Researchers took their studies even further by doing a study with identical mice that were “humanized”, meaning they were injected with gut bacteria from humans. The mice received either bacteria from a twin that was obese or bacteria from the obese twin’s thin sibling. The mice were kept in a sterile environment to prevent other bacteria from influencing their microbiome. Even though the mice were fed identical diets, the mice who received bacteria from the obese twin had more body fat than the other mice. These mice also had less bacterial variety. This study supports a previous study’s findings that gut bacterial diversity is directly related to body fat and weight.

A western diet, high in fat and processed foods and low in fiber and fresh produce, is also related to fewer strains of gut bacteria in studies with mice. More research is being conducted on the impact of the microbiome on obesity in humans. It is more complicated than the studies with mice because of the genetic variation in humans, even in groups that seem very similar. However, scientists believe that the microbiome needs to be considered for weight loss, along with a healthy diet and exercise.


Boost your gut microbiome diversity by:


Eating fermented foods
  • Kimchi (Korean mix of fermented spicy vegetables)
  • Sauerkraut (fermented cabbage)
  • Kefir (a fermented milk drink)
  • Kombucha (fermented tea and sugar drink)
  • Miso (fermented soybean paste)
  • Crème fraiche (French fermented cream, similar to sour cream)
Eating prebiotic foods (which feed and promote growth of your microbiome)
  • Root vegetables
  • Dark leafy greens
  • Nuts
  • Other high fiber whole foods such as grains and beans
Taking probiotic supplements


Talk to your nutritionist about how you can influence your gut microbiome!


By student intern Jessica Thramer



“Microbiome: Your Body Houses 10x More Bacteria Than Cells.” Discover: Science for the Curious. Discover Magazine, 7 Aug. 2010. Web. 21 Nov. 2015.

Wallis, Claudia. “How Gut Bacteria Help Make Us Fat and Thin.” Scientific American Global RSS. Scientific American, 1 June 2014. Web. 19 Nov. 2015.