Probiotics and Weight Management: Do They Help?

There are microorganisms all over your body, and not all of them are harmful. Beneficial bacteria, known as probiotics, can be consumed in the form of dietary supplements or discovered in fermented foods like yoghurt. Probiotics are often used by antibiotic-takers to restore healthy microorganisms to their digestive systems. For proper digestion and immune system maintenance, your body requires probiotics. Some studies have even linked them to reduced calorie intake and subsequent weight loss¹.

Have probiotics been shown to aid with weight loss^1-4?

The human body is home to numerous microorganisms, most of which are beneficial bacteria. Some of these microorganisms have been linked by researchers to possible effects on appetite and body weight.

Friendly bacteria in the digestive tract aid in the process of breaking down and absorbing nutrients from the food we eat. They contribute to the production of vitamins and minerals that the body can use. Fibers are digested by the probiotic bacteria, which then produce beneficial chemicals.

Dysbiosis, an imbalance of the bacteria that live in the digestive tract, can be the result of poor digestive health.

It's possible that there won't be enough "good" bacteria around to keep the bad ones in check if hazardous microbes proliferate unchecked. It's also correlated with less microbial variety in the stomach.

Obesity may have multiple causes, but a 2013 study reveals that gut dysbiosis may play a role in its development.

Those who are overweight and those who maintain a healthy weight have quite different gut flora, as pointed out by the lead author of a study published in 2015⁵.

They discovered that altering an animal's gut flora led to weight loss or increase. But altering the gut microbiome had no effect on human weight loss or growth.

However, these findings are consistent with the idea that weight gain causes a change in the composition of a person's gut microbiome. Obesity seems to be caused by factors other than the changes that have been seen.

The study's author singled out the following variables as potential contributors to a shift from a lean to an overweight pattern of gut flora:

extreme dietary fat content the consumption of artificial sweeteners, eating a high-calorie diet, and having an irregular sleep schedule. It has been suggested that certain probiotics may aid weight loss, however this is only supported by a tiny amount of evidence.

In a study published in The British Journal of Nutrition, researchers looked at how the probiotic Lactobacillus rhamnosus affected overweight participants.

Within the study population, weight loss was greater among the women who took the probiotic compared to the placebo group. Plus, once they stopped dieting, the people who took the probiotic pill still managed to shed more pounds than the control group. However, men did not have the same side effects.

The results of a 2013 study analysing the effects of Lactobacillus fermentum and Lactobacillus amylovorus were also examined.

Yogurt containing these Lactobacillus strains was consumed by overweight, otherwise healthy participants over a period of 6 weeks in the study. In general, after this time period, the subjects had reduced their body fat percentage by between 3 and 4%.

The role of Lactobacillus gasseri in promoting weight loss has also been investigated. Individuals with excess abdominal fat who consumed fermented milk products containing the beneficial bacteria lost 8.2% to 8.5% of the fat in the abdominal region over the course of 12 weeks⁶.

This abdominal fat, however, returned once they stopped consuming the milk. This data suggests probiotics can aid weight loss in certain people, though additional research is needed to confirm this.

Obesity may be linked to low bacterial diversity. For instance, one reviewer in 2015 reported that reduced variety of gut microbes is associated with increased inflammation.

Conditions associated with obesity, such as metabolic syndrome and type 2 diabetes, may be exacerbated by a lack of microbial diversity.

Considering these details, it's clear that consuming probiotics may help with not just weight loss, but overall health as well.

1. What to Know About Probiotics for Weight Loss. WebMD Learn more.
2. Álvarez-Arraño, V. & Martín-Peláez, S. Effects of Probiotics and Synbiotics on Weight Loss in Subjects with Overweight or Obesity: A Systematic Review. Nutrients 13, 3627 (2021).
3. Probiotics and Weight Loss: How and Why They Work. Learn more.
4. Probiotics for weight loss: Do they work? Learn more (2019).
5. Bell, D. S. H. Changes seen in gut bacteria content and distribution with obesity: causation or association? Postgrad Med 127, 863–868 (2015).
6. Guarner, F. The gut microbiome: What do we know? Clin Liver Dis (Hoboken) 5, 86–90 (2015).