Probiotics are live microorganisms that have health benefits when eaten (1).
They are found in both supplements and fermented foods.
Probiotics may improve digestive health, heart health and immune function, to name a few (2, 3, 4, 5).
Several studies also suggest that probiotics can help you lose weight and belly fat.
There are hundreds of different microorganisms in your digestive system.
majority of these are bacteria, most of which are friendly. Friendly
bacteria produce several important nutrients, including vitamin K and
They also help break down fiber that the body can't digest, turning it into beneficial short-chain fatty acids like butyrate (6).
are two main families of good bacteria in the gut: bacteroidetes and
firmicutes. Body weight seems be related to the balance of these two
families of bacteria (7, 8).
Both human and animal studies have found that normal-weight people have different gut bacteria than overweight or obese people (9, 10, 11).
In those studies, people with obesity had more firmicutes and fewer bacteroidetes, compared to normal-weight people.
are also some animal studies showing that when the gut bacteria from
obese mice are transplanted into guts of lean mice, the lean mice get
All of these studies suggest that gut bacteria may play a powerful role in weight regulation.
It is thought that certain probiotics may inhibit the absorption of
dietary fat, increasing the amount of fat excreted with feces (12).
In other words, they make you "harvest" fewer calories from the foods in your diet.
Certain bacteria, such as those from the Lactobacillus family, have been found to function in this way (12, 13).
Probiotics may also fight obesity in other ways:
- Release of GLP-1:
Probiotics may help release the satiety (appetite-reducing) hormone
GLP-1. Increased levels of this hormone may help you burn calories and
fat (14, 15).
- Increase of ANGPTL4: Probiotics may increase levels of the protein ANGPTL4. This may lead to decreased fat storage (16).
There is also a lot of evidence that obesity is linked to inflammation in the brain. By improving gut health, probiotics may reduce systemic inflammation and protect against obesity and other diseases (17, 18).
However, it is important to keep in mind that these mechanisms aren't understood very well. More research is needed.