Did you know that your gut is home to trillions of microbes? This bacteria is needed to assist with digestion, but it is also believed to contribute to our weight. Here’s how your gut bacteria can influence your weight. (1)

Microbiota: Link Between Gut Health & Weight?

All of us have microbes in our bodies including bacterial, fungal, and protozoal microorganisms collectively called “microbiota”. Your intestinal microbiome could be linked with your risk for weight gain and even obesity. This is because obesity and obesity-related metabolic disorders show alterations in the composition and function of the human gut microbiome. (1)

According to studies, your gastrointestinal microbiota can play a key role in influencing energy use from the food you eat. This in turn can affect your “host genes” which regulate energy expenditure and storage. Because the microbiota is not fixed, dietary components can influence how you use energy. (1)

Gut Health And Weight Loss

If this is the case, it could be possible that manipulating the gut microbiota could help with weight loss. In fact, it could even be the key to obesity prevention. Possible treatments could include targeting the microbiota to help restore or modulate its composition. This would include taking probiotics, nondigestible, or limited digestible food constituents like prebiotics or symbiotics. Some studies even suggest the idea of “fecal transplants”. (1)

Gut Microbiota And Energy

Your gut microbiota produce additional energy you can’t normally access in a few ways. (1) They: 

  • Break down soluble fiber
  • Produce important vitamins like biotin, folate, and vitamin K
  • Metabolize xenobiotics preventing pathogens like those found in undercooked meat from making you sick
  • Assist in the development of a mature immune system

As mentioned, gut microbes are crucial to energy extraction from food. For example, those complex carbohydrates most of us love can’t be digested, but your gut microbes can metabolize them into short-chain fatty acids (SCFA), such as butyrate. This is the primary energy source for colonic epithelial cells needed to maintain a well-balanced relationship between gut microbes and your immune system. (1,2)

Gut Health And Weight Studies

The link between obesity and gut microbiota was based on studies in germ-free mice without microorganisms in their gut. It was noted that conventionally raised mice have a 40% higher body fat content and 47% higher gonadal fat content. This is despite the fact they consume less food than germ-free mice. The study observed what would happen if they transplanted the distal gut microbiota from the normal mice into the gnotobiotic mice. The result was a 60% increase in body fat within two weeks even though there was no increase in food consumption or exercise. (1)

Hope For Gut Health And Weight Treatments

All in all, current evidence seems to indicate there is a potential role human gut microbiota plays in obesity. The bacterial composition of gut microbiota differs between obese and lean people for those on a typical “Western diet” high in fat and refined carbohydrates. This could be a possible reason intestinal bacteria linked to obesity increases. So, will altering the microbiota reduce obesity risk? Or is it more that microbiota might be the key to creating personalized diets to prevent obesity as some studies suggest? (1)

Continuing studies will help raise hopes for those who struggle with weight issues. Perhaps studies using artificial intelligence to analyze gut microbiomes can eventually produce dietary interventions and healthy recipes that keep us all at our ideal weight. (1)


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5082693/
  2. https://www.nature.com/articles/emm201720