Obesity, diabetes and non-alcoholic fatty liver disease (NAFLD, which is excessive fat accumulation in the liver) are a growing global health problem. Researchers believe that lifestyle, especially a poor diet, contributes to the rapid progression of these diseases. Studies show that patients with metabolic diseases such as type 2 diabetes, obesity and NAFLD also have dysbiosis, which is an imbalanced gut microbiota. Dysbiosis is characterized by decreased levels of beneficial bacteria.  Metformin, a common drug given to type 2 diabetes patients to regulate blood sugar levels, modulates the gut microbiota in a way that leads to improved blood glucose levels.

According to the WHO and the Food and Agriculture Organization of the United Nations (FAO), probiotics are “live microorganisms which, when administered in adequate amount, confer a health benefit on the host”. Although evidence supports probiotic intake for obesity management, few studies have analyzed the role probiotics play on other metabolic diseases such as type 2 diabetes and NAFLD.

Despite scientific evidence supporting probiotic intake for managing obesity, few studies have analyzed the role probiotics play in other metabolic diseases.

A recent literature review of 105 studies performed on overweight but not obese patients revealed that probiotics improve weight loss. Specifically, consuming a probiotic that contained three or more strains during eight weeks improved markers of metabolic health such as a slight decrease in weight loss, body fat mass and waist circumference in overweight individuals.

In individuals with type 2 diabetes, regular probiotic consumption improved blood sugar levels and resulted in decreased body weight and inflammation that are often seen in patients with metabolic disease. Interestingly, probiotics did not improve insulin resistance in patients with fatty liver disease but did ameliorate other markers of metabolic health such as reduced body weight, waist circumference and liver enzyme production.

Consuming a probiotic that contained three or more strains over an 8-week period improved markers of metabolic health, one of them being a slight decrease in weight.

The authors conclude that different strains of probiotics may work synergistically to cause diverse effects on host metabolism such as fat absorption, sugar digestion, inflammation as well as the production of the beneficial metabolites short chain fatty acids. However, the exact mechanisms behind the action of probiotics remain to be discovered; therefore, more studies are needed. Nevertheless, this article sheds light on the potential for multistrain probiotics to compliment traditional treatments in patients with a metabolic disease, such as changes in diet and increasing physical activity.



Koutnikova H, Genser B, Monteiro-Sepulveda M, et al. Impact of bacterial probiotics on obesity, diabetes and non-alcoholic fatty liver disease related variables: a systematic review and meta-analysis of randomised controlled trials. BMJ, 2019. doi: 10.1136/bmjopen-2017- 017995

Allison Clark
Allison Clark
Allison Clark has a master in nutrition and health from Open University in Barcelona and a master in journalism. She is a freelance writer and nutritionist and has written various peer review papers about the role the gut microbiota plays in health, disease and endurance exercise performance. Allison is passionate about the role diet and the gut microbiota play in health and disease. Follow her on Twitter @Heal_your_Gut