Gut bacterium may help maintain weight loss

Many people successfully lose weight, only to regain some or all of it once they stop dieting. This is partly because the body adapts and tries to return to its previous weight. This makes the search for ways to maintain a stable weight after dieting particularly important.

The study involved 90 adults with overweight or obesity. Participants first followed a strict eight-week diet, during which they lost an average of around 11 kilograms. This was followed by a 24-week period in which they maintained a healthy eating pattern. During this second phase, half of the participants received a daily supplement containing a pasteurised (non-living) form of the gut bacterium Akkermansia muciniphila. The other half received a placebo.

The results showed that participants who received the supplement were better able to maintain their weight loss. They regained significantly less weight than the group that didn’t receive the supplement. On average, this resulted in around three kilograms higher weight loss after 24 weeks as compared to the placebo group.

Notably, around 40 percent of participants receiving the supplement continued to lose weight, while this was rarely seen in the placebo group.

The researchers believe the bacterium may help in several ways:

• the body appears to lose slightly more energy through stool
• fat tissue shows less inflammatory activity and a more active metabolism

The study also found that insulin sensitivity, which is important for blood sugar regulation, was better preserved in participants who took the supplement. The effect was strongest in people who naturally have low levels of this bacterium in their gut. After six months, this group had lost around five kilograms more than people with naturally high levels of the bacterium. They also showed the greatest health improvements. 

‘The finding that people with low levels of this gut bacterium show the strongest response is good news,’ says Willem de Vos, emeritus professor of microbiology at Wageningen University & Research, who discovered Akkermansia. ‘They are often precisely the people who are overweight.’

The researchers stress that their discovery is not a substitute for a healthy lifestyle. Diet and exercise remain fundamental. However, the findings do suggest that this bacterium could become an additional tool for maintaining weight loss in the long term. 

‘Our results show that in the context of a healthy diet this gut bacterium can contribute to better weight management,’ concludes Ellen Blaak, professor of human biology at Maastricht University. ‘Daily supplementation with this bacterium could therefore be a useful strategy for the prevention and treatment of obesity.’