Akkermansia muciniphila may help prevent weight regain after weight loss

Losing weight can be difficult, and maintaining that loss is frequently harder still.

Research indicates that most people who deliberately lose weight put at least part of it back on within a few years.

This is commonly blamed on a lack of "willpower", yet evidence suggests that weight loss triggers a variety of biological changes in the body that promote regaining weight.

These changes include greater hunger, metabolic alterations and changes in the hormones that regulate appetite.

People who lose weight with a GLP-1 drug can also struggle to sustain their weight loss when treatment ends.

As a result, identifying ways to help people maintain weight loss has become an important research priority.

A new study in Nature Medicine indicates that a particular gut microbe could help reduce weight regain.

Akkermansia muciniphila and the gut microbiome

The bacterium, known as Akkermansia muciniphila, is a plentiful species within the human gut microbiome. It resides in the mucus layer lining the gut.

It can consume mucin, the proteins and sugars that form this mucus. The bacterium is thought to help maintain the gut’s protective barrier and may also affect metabolism.

In recent years, Akkermansia muciniphila has become a focus of microbiome research because it has been associated with better health outcomes in a range of diseases.

Human studies have linked higher levels of Akkermansia muciniphila to improved metabolic health, including better blood sugar regulation. This can lower the risk of conditions such as type 2 diabetes.

Conversely, people with obesity and type 2 diabetes tend to have lower levels of Akkermansia muciniphila.

The latest research examined whether giving people Akkermansia muciniphila supplements after they had lost weight could limit later weight regain.

The trial enrolled 90 adults who were overweight or obese. For eight weeks, participants followed a low-energy diet made up of meal-replacement soups and shakes providing 800-900 calories a day.

Following this stage, those who had lost at least 8% of their body weight were randomly allocated either a placebo or daily supplements containing pasteurised Akkermansia muciniphila for 24 weeks.

Participants were also asked to follow a healthy eating pattern consistent with Dutch dietary guidelines, although they were free to eat as much or as little as they wished.

The weight-regain trial results

The study did not use live Akkermansia muciniphila. Instead, participants received a pasteurised form, meaning that the bacteria had been heat-treated and were no longer alive.

Although this may seem counterintuitive, earlier research indicates that certain benefits of probiotics, including A. muciniphila, may arise from components of bacterial cells rather than live microbes.

Pasteurisation may even strengthen the microbe’s effects.

At the end of the trial, participants given Akkermansia muciniphila had regained significantly less weight than those given the placebo.

On average, supplement users regained about 1.2kg, while the placebo group regained 3.2kg.

This indicates that supplementation slowed weight regain after the initial loss, although it did not eliminate it entirely.

Researchers also noted improvements in certain cardiometabolic measures in the supplemented group, including greater insulin sensitivity, meaning that the body responded to insulin more effectively.

The microbiome is extremely complex.

Diet, exercise, sleep, medication and numerous other influences affect it. Consequently, microbiome-based treatments are unlikely to offer straightforward, universal solutions.

While the results are promising, the study was fairly small and lasted for only six months after the initial weight-loss stage. Whether the effects would persist for longer remains unknown.

It is also unclear who is most likely to benefit. Participants who began the study with lower gut levels of Akkermansia appeared to experience greater cardiometabolic improvements.

This underlines a wider difficulty in microbiome science: gut microbiomes differ greatly between individuals, so a treatment that works well for one person may have minimal impact on another.

Diet, lifestyle and microbiome therapies

The research also included considerable dietary intervention and support. This involved providing a meal-replacement plan for the initial weight-loss period and dietitian support throughout the full study.

Therefore, the microbe was not assessed separately from lifestyle changes, and it should not be regarded as a replacement for them.

It is also important to note that several authors disclosed links to the company that produced the supplement used in the trial.

Although these partnerships are common in translational research, which tests laboratory findings in real people to understand potential health benefits, independent studies will be needed to verify and extend the findings.

Nevertheless, the microbiome remains a compelling and increasingly significant research field, with clear connections to many aspects of human health. Knowledge of it is still evolving.

Research to date, however, shows that the microbiome has important roles in metabolism and immunity, allowing it to influence both health and disease development.

Many probiotic supplements currently sold to consumers have limited supporting evidence.

Although studies such as this one indicate that carefully targeted microbiome therapies may eventually form part of weight-maintenance strategies, substantially more research is required.

It may also be possible to encourage and increase Akkermansia muciniphila without using supplements.

Diet is a major influence on the composition of the microbiome.

Eating a diet high in fibre, especially prebiotic fibres - dietary fibres that feed beneficial gut bacteria - can create conditions in which helpful bacteria, including Akkermansia muciniphila, are able to thrive.

These fibres occur in foods including onions, garlic, leeks, asparagus and many wholegrains.

Plant foods containing high levels of polyphenols, naturally occurring plant compounds that may protect cells from damage and inflammation, may also support its growth. Such foods include berries and grapes.

For now, the study’s findings add to the expanding evidence that body weight is shaped by a complex interaction of biological, environmental and behavioural influences.

They also add to the increasingly clear understanding that the gut microbiome is an important regulator of metabolism and health.

Rachel Woods, Associate Professor, University of Nottingham; University of Lincoln

This article is republished from The Conversation under a Creative Commons licence. Read the original article.