The Microbiome and it's effects Weight Management

 What is the Microbiome?

Did you know that we have about as many bugs in our bodies as we do human cells? Despite our attempts to avoid invasion by harmful microorganisms, our bodies are actually flooded with trillions of microorganisms of thousands of different specifies, including bacteria, fungi, parasites, and viruses. In healthy individuals, these microbes, found in the gut, mouth, skin, and other body-parts, co-exist and are collectively known as the microbiota, or the microbiome [R]. 

The Microbiome and Health

Growing research on the microbiome has dramatically reshaped our understanding of human biology. Studies on these “bugs” not only led to an enhanced understanding of how microbes mediate digestion and disease, but they also revealed surprising associations with diabetes, autism, depression, and Parkinson’s disease [R, R, R]. As a result, the microbiome is often labeled as a supporting organ because of its key role in the regulation of the human body.  

The effect of the microbiome on health is fundamental and ranges from beneficial to unfavorable, depending on its precise composition. Like fingerprints, everybody has a unique microbiome; it’s first assembled at birth, during exposure to microbes in the birth canal, and later develops depending on environmental factors like medication and diet [R]. 
 

Diet Affects the Microbiome

When we eat, we take in a lot of microbes- some good, some not. Luckily, we can influence our microbiome to lean more towards a favorable composition by eating certain foods. 

You’ve surely heard or seen the words “probiotics” and “prebiotics” at the supermarket. Probiotics are a group of bacteria that include the strains Lactobacillus and Bifidobacterium. These are beneficial bacterial strains that help prevent the attachment of pathogenic, or disease-causing, bacteria on our gut wall. They also improve insulin resistance and control inflammation [R, R].

Prebiotics are foods, typically fibers, that promote the growth of beneficial bacteria. Fibers are usually indigestible; they pass through the digestive tract and promote the growth of a wide range of beneficial bacteria, shown to reduce appetite, improve insulin sensitivity, and enhance the breakdown of fats.

Gut Microbiome and Weight Management

The functioning of the digestive tracts and the ability to extract energy from food are largely dependent on the gut microbiome. When we eat, gut microbes work to stimulate the production of various hormones that can have many effects on the body, including stimulation of satiety and regulating metabolism [R]. Particularly when we eat fibers, gut microbes make our gut create a compound called GLP-1, which sends a signal to the brain to stop eating. It should be no surprise, then, that the gut microbiome is involved in weight management.

The ability of gut microbes to assist in energy extraction and metabolism depends on the microbiome composition and growing evidence links certain microbiome changes to the development of obesity. In particular, a gut microbiome profile that includes an increase in Firmicutes, and a decrease in Bacteroidetes, Bacteroides, Bifidobacterium, is associated with obesity [R, R]. In contrast, a profile with a decrease in Firmicutes and increased Bacteroidetes is observed in lean individuals.

However, getting a gut microbiome transplant isn’t the solution for weight loss. Research on the gut microbiome is still growing because it’s a relatively new field that’s yet to be discovered to its fullest [R].