Can Gut Bacteria Affect How We Store Fat?


How Gut Bacteria Affects Our Body

Woman Looking at her Stomach
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Gut bacteria or microbes live in our digestive tract helping us digest food, prevent infection, and shown to play a role in our physical fitness. Gut flora, gut microbiota, and gastrointestinal microbiota are other common names used for gut bacteria.

Our gut contains the largest amount of bacteria compared to other parts of the body and with an estimated 500 to 1,000 variety of species. These species are broken down into trillions of microbes that populate the gut.

We begin forming gut bacteria from birth and microbial balance is established from our food and environment. There are constant shifts of good and bad gut bacteria in response to what we eat working to balance the digestive tract. When we consume unhealthy food, we feed the bad bacteria causing a negative imbalance. 

According to research, gut bacteria can influence fat stores through energy extraction from the diet. This means what we’re eating directly affects the microbes in our gut. Microbes have many different roles in the body, but also work to increase fat or helping us maintain a healthy weight. It’s the abundance of bad bacteria that stimulates fat formation. Having more bad bacteria in our gut will also mean having more fat stores on our body. 

Studies indicate gut bacteria changes over time in response to changes in our diet and health conditions. How we eat is shown to alter either our good or bad gut bacteria.

Researchers are looking at gut bacteria as a contributing factor to a growing obesity epidemic. The evidence appears to indicate unhealthy gut flora impairs our ability to lose fat.


More Bad Gut Bacteria Means More Fat

Gut microbes are shown to differ between lean and obese humans as well as mice. Evidently, imbalances in our gut bacteria are linked to obesity and associated diseases. Studies are indicating more bad gut bacteria means more body fat stores. 

One study examined how gut microbes affected healthy mice. The research included taking gut microbes from four sets of human twins and introducing them into germ-free mice. One set of twins was lean and the other obese. The microbes (gut bacteria) taken from the lean twins produced lean mice, and bacteria from the obese twins resulted in fat mice. 

According to research results, the microbes from the lean twin had a positive effect on metabolism and improved fat oxidation (burning).  

An interesting outcome happened when all mice were placed in the same cage. The lean gut bacteria transferred to the obese mice causing them to lose weight and develop bacterial profiles similar to the lean mice. 

Research results do show bad gut bacteria as one of the possible causes of obesity. The important takeaway from all this is to avoid diets stimulating the growth of bad gut bacteria. This means avoiding processed foods high in saturated fats and sugar. 

In order to improve good gut bacteria and create intestinal flora like the lean mice, eating a healthy diet is essential. This would include eating a wide variety of vegetables, whole grains, and fruits.


Gut Bacteria and Bad Food Cravings

In addition to altering our ability to lose fat, it appears bad gut bacteria increases unhealthy food cravings. This can occur because of unbalanced microbes (gut bacteria) according to research. 

A study examined how eating behavior was manipulated by gastrointestinal microbiota (gut bacteria). Our body is composed of a diversity of organisms competing for nutritional resources.

It appears the constant conflict between our body and microbiota may lead to cravings and unhealthy food choices

Unhealthy cravings may be due to the bad microbes that benefit from those foods. Science is simply saying bad gut bacteria wants to be kept alive by the host (you) feeding it what it wants to be maintained. 

Prioritizing nutritious foods may help suppress microbial signals that originate in the gut. According to research, eating healthier can reduce our food cravings by intervening in our microbiota. Reducing bad gut bacteria would help reduce food cravings, make a positive change in our intestinal flora, and enable us to lose weight.


How to Improve Good Gut Bacteria

What we eat plays an important role in maintaining healthy gut bacteria. Promoting a healthy digestive tract full of good microbes will require reducing foods promoting bad gut bacteria. Bad gut bacteria feeds off diets high in saturated fat and low in fruits and vegetables. Implementing changes to increase good gut bacteria is essential for fat loss and overall health. You will find the following tips helpful to improve intestinal flora:

  • Healthy nutrition - eat a high fiber, whole foods diet. Incorporate foods like beans, nuts, seeds, whole grains, fruits, and vegetables, all of which feed good gut bacteria. 
  • Eliminate processed foods - keep sugar intake, animal fats, and processed foods to an absolute minimum or eliminate completely to encourage the growth of good bacteria. 
  • Pre and probiotics - research is linked to good gut bacteria restored through daily supplementation of pre and/or probiotics. Probiotics may improve gut flora and digestive health creating a happy environment for good gut bacteria. Consult with your doctor before taking any supplements including pre and probiotics. 
  • Things to avoid - antibiotics, acid blockers, and anti-inflammatories are indicated to destroy good and bad bacteria and do not create a favorable gut environment. Antibiotics should only be used when necessary and prescribed by a physician. 

Bonus - Best Foods to Improve Your Gut Bacteria

Apple cider vinegar – stimulates hydrochloric acid (HCL) to help maintain proper acidity and normal pH levels in the body. Promotes good gut bacteria and fat loss

Plain yogurt – rich source of natural probiotics. Contains live active cultures S.thermophilus, L. bulgaricus, L.acidophilus, and Bifidobacteria (good gut bacteria)

Fermented foods – sauerkraut is a naturally fermented food containing Lactobacillus bacteria (good gut bacteria)

Mangos – nutrient profile is shown to improve gut health, reduce body fat and maintain normal sugar levels

Kefir – drinkable yogurt full of live and active strains of good gut bacteria 

Coconut oil - medium chain fatty acid. Contains lauric and caprylic acids shown to reduce bad gut bacteria and maintain healthy stomach acidity levels

Garlic – natural prebiotic helping to fuel and maintain existing healthy intestinal flora

A Word From Verywell

Gut bacteria plays an important role in how our body stores fat. We can make positive improvements in reducing body fat by changing our intestinal flora. This is done by applying healthy eating habits that will increase our good gut bacteria while reducing bad microbes. Our body functions may be working constantly to balance our gut bacteria, but it will be the implementation of a healthy diet that enables us to maintain a healthy gut. 

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Article Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Krajmalnik-Brown R, Ilhan ZE, Kang DW, DiBaise JK. Effects of gut microbes on nutrient absorption and energy regulationNutr Clin Pract. 2012;27(2):201-214. doi:10.1177/0884533611436116

  2. Katherine Wendelsdorf, Ph.D., Gut Microbes and Diet Interact to Affect Obesity, National Institutes of Health, 2013

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