What is already known on this topic
The gut commensal Akkermansia muciniphila protects mice from a range of obesity-related conditions such as insulin resistance, hypercholesterolemia, or the storage of body fat. But whether A. muciniphila exerts the same protective effect in people is unknown.
What this research adds
Researchers looked at obese people who were given a daily supplement of A. muciniphila bacteria that had been pasteurized. Compared to those who received a placebo, people who consumed the bacteria had lower cholesterol levels and improved insulin sensitivity.
The findings show the feasibility of administering A. muciniphila to people in the form of a food supplement and suggest that the bacteria could reduce the risk of heart and metabolic diseases.
People with obesity-related conditions may benefit from supplements of a specific gut microbe, a small proof-of-concept study suggests. The results, published in Nature Medicine, open the way for a larger human trial that could turn the discovery into a commercially-available food supplement.
Previous studies have shown that the gut commensal Akkermansia muciniphila protects mice from a range of obesity-related conditions such as insulin resistance, high cholesterol levels, and the storage of body fat. But whether A. muciniphila exerts the same protective effect in people is unknown.
To address this question, Clara Depommier and Amandine Everard at the Catholic University of Louvain and their colleagues looked at obese people who were given a daily supplement of A. muciniphila bacteria that had been killed with heat, or pasteurized. The bacterium is a normal inhabitant of the human gut and is less prevalent in people with metabolic syndrome.
Proof of concept
The pilot study included 32 overweight or obese volunteers with insulin resistance. The volunteers were randomly assigned to three groups, which were given daily oral supplements of either placebo, live A. muciniphila, or pasteurized A. municiphila for three months. The participants were asked to stick to their diets and normal levels of physical activity.
The results confirmed what had already been observed in mice: ingesting the pasteurized bacterium improved insulin sensitivity, reduced cholesterol levels and inflammation markers, and led to a slight decrease in the body weight of the participants (2.3 kg on average). The weight loss, however, was not statistically significant.
In contrast, participants who were given a placebo had increased insulin resistance and cholesterol levels. The live bacteria were ineffective, too.
The supplementation of pasteurized A. municiphila appeared safe for people and had no side effects. What’s more, it didn’t lead to any changes in the gut microbiota.
The findings show the feasibility of administering A. muciniphila to people in the form of a supplement and suggest that the bacteria could reduce the risk of heart and metabolic diseases. But more work is needed to see whether the effects of the bacterial supplement hold over time, the scientists say.
The researchers are now planning to start a large-scale trial in people to confirm these first results. If the trials prove successful, they could endorse the commercialization of the bacteria as food supplements as early as 2021. The researchers say that anyone wishing to reduce their risk of heart and metabolic diseases might take advantage of the supplement, especially if combined with a healthy diet.