Weight management with
Hafnia alvei HA4597®

Mechanism of Action Molecular Mimicry of a Satiety Hormone (a-MSH) by Bacterial Protein

1. Molecular mimicry:
the role of ClpB in appetite regulation

TargEDys founders, Professors Déchelotte and Fetissov studied and described different metabolic pathways involved in appetite regulation through the microbiome-gut-brain axis. They focused especially on the satiety hormone alpha-MSH and its antigens.

As part of their research, they identified a microbiota-produced metabolite involved in the regulation of appetite: Caseinolytic peptidase B (ClpB).

This bacterial protein presents a similarity of sequence and structure to the satiety hormone alpha-MSH.

ClpB is able to connect to alpha-MSH receptors, activating the a-MSH pathways of satiety: this is molecular mimicry.


2. ClpB mechanism of action

ClpB role

3. The strain Hafnia alvei HA4597® produces ClpB


Scientific evidence From pre-clinical to clinical

1. Pre-clinical evidence

ClpB DNA / Plasma

Legrand R. et al. International Journal of
Obesity (2020)

Hafnia alvei HA4597 increases fecal and plasmatic ClpB levels compared to placebo in Ob/Ob hyperphagic and high-fat diet mice – two models of obesity.

Body weight gain /Days

Legrand R. et al. International Journal of
Obesity (2020)

This study also showed Hafnia to significantly reduce body mass gain in both Ob/Ob hyperphagic mice and high-fat diet mice.

Basal Glycerine

Lucas N. et al. Microorganisms (2020)

Hafnia alvei HA4597 significantly reduces overall weight gain in hyperphagic mice on a high-fat diet, and improves glycemia levels compared to the high-fat diet and to the Orlistat group.

2. Clinical evidence: efficacy confirmed through a clinical trial at pharmaceutical standards

Protocol: Randomized, Double-blind, Placebo-controlled, Multicentric Studyl

Supported by pre-clinical results confirming the mechanism of action and showing positive results on weight management, TargEDys performed a 3-months clinical study at pharmaceutical standards on 230 overweight people.

  • Hafnia alvei HA4597® (5×1010 cells per capsule) vs. Placebo
  • 2 caps per day
  • 230 overweight subjects in 2 arms (BMI: 25kg/m2 to 29.9kg/m2)
  • Hypo-caloric diet (-20%) for both arms
  • 12 weeks of treatment

Main results

Subjects / Body weight loss


Significantly more subjects lost at least 3% of baseline body weight at 12 weeks in the treated group compared to the placebo group (HA4597: 57.7% vs. Placebo: 41.7%; p=0.028).

Change in VAS / Change in feeling of fullness


The treated group felt a significant increase in fullness at 8 weeks (p=0.009) and 12 weeks (p=0.006) versus baseline and compared to the placebo group at 12 weeks (p=0.009). The treated group shifted from feeling hungry (<50% fullness) to feeling full during the study despite the hypocaloric diet.

Subjects / Global benefits assessment


The benefit was rated as “very good” or “good” by 68% of subjects in the treated group compared to 53% of subjects in the placebo group (p=0.019).

-20% Hypo-caloric Diet + Increase Feeling of Fullness = INCREASE OF SATISFACTION


Reduction in hip circumference
Reduction in total and LDL Cholesterol
Reduction in Glycemia

Market needs & potential

percent of adults were overweight(WHO, 2016)
percent of adults were obese(WHO, 2016)
million people die each year, from obesity associated complications (type 2 diabetes, heart disease, and cancer).(WHO, 2016)

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