Appetite-suppressing probiotic helps overweight people lose weight

Consuming the bacterium Hafnia alvei twice a day for three months led to better weight loss success among a group of overweight people following a calorie-control diet

By Carissa Wong

The bacterium Hafnia alvei produces a molecule that mimics an appetite-reducing hormone

Leibniz-Institut DSMZ

An experimental probiotic aids weight loss in overweight people following a calorie-control diet.

Previous studies by Pierre Déchelotte at Rouen University Hospital in France and his colleagues suggest that orally administering the gut bacterium Hafnia alvei helps obese mice lose weight. The probiotic produces a molecule called ClpB that mimics the appetite-reducing hormone alpha-MSH.

Now, the researchers have found that the bacterium has similar effects in people who are overweight, presenting their results at the Targeting Microbiota 2022 conference in Paris last week.

The researchers counselled 212 people with an overweight body mass index (BMI) on how to reduce their calorie intake by one-fifth for three months. BMI is a measurement that uses your weight and height to calculate if your weight is healthy. The participants were asked to maintain their existing level of physical activity.

Over the three months, roughly half of the participants also took a pill containing H. alvei twice a day. The remaining participants took a twice-daily placebo. The people in both groups were of a similar age, height and starting weight.

Among those who took the probiotic, 55 per cent lost at least 3 per cent of their body weight, compared with 41 per cent of the people taking the placebo.

Among people who are overweight, a 3 per cent loss in body weight has been linked to a reduced risk of type 2 diabetes and cardiovascular disease. In support of this, the researchers found that the participants who took the probiotic had substantially lower blood sugar levels than those in the placebo group, reducing their risk of developing type 2 diabetes. None of the participants had type 2 diabetes.

Monthly surveys also revealed that the people who took the probiotic felt substantially more satiated in general at two and three months into the experiment, compared with those on the placebo.

Although it is unknown how food intake may have differed between the two groups, those taking the probiotic could have lost more weight if H. alvei induced a feeling of fullness that caused them to eat less. The researchers also cannot rule out the bacterium affecting how fat is broken down.

“It’s very interesting to see that you can modulate body weight in this way using certain bacteria strains,” says Adèle Rakotonirina at the University of Geneva, Switzerland. “This could really help if you want to make a therapy against obesity.”

However, probiotics affect people differently depending on their genetics, gut microbiome and overall metabolism, says Rakotonirina. “Ultimately, we would need a personalised approach to prescribe probiotics to minimise any side effects,” she says.