Conducted by researchers from Clinical Research Center Kiel and Johannes-Gutenberg University in Germany, and CitrusLabs in Las Vegas, the 12-week randomized, double-blind clinical trial assessed the efficacy of the plant-derived postbiotic in managing weight and associated parameters in 60 participants.
The results, reported in Nutrients, indicated body fat mass, body weight, waist circumference and visceral fat all reduced in the postbiotic group, compared to the placebo group. What’s more, the postbiotic group tended to feel more in control of their weight and their muscle mass tended to increase.
The study was sponsored by Austrian supplement manufacturer Slimbiotics and represents the first published human clinical trial on the heat inactivated L. fermentum strain K8-Lb1, building on work with the live strain which is clinically backed for weight management and metabolic health.
“What makes this study particularly interesting is that, even as a pilot, we already saw clear and consistent improvements across key weight management parameters,” said Juan Victor Wang Xu, Slimbiotics’ director of strategy & operations.
He noted one especially noteworthy finding was a trend toward increased muscle mass despite overall weight loss.
“This is highly relevant in the current context, where loss of lean mass is a known concern, particularly with GLP-1-based approaches. It’s definitely something we plan to explore further.”
The team further observed a significant improvement in concentration ability, which Wang Xu said was “somewhat unexpected but encouraging”, and potentially pointed toward a gut–brain connection.
He added that this sort of clinical backing is particularly important at this time of heightened interest in weight management solutions.
“From a market standpoint, interest in biotics for weight management and metabolic health continues to grow, particularly alongside the rise of GLP-1 medications,” he said. “We are seeing increasing demand for our biotics and complementary, non-pharmaceutical solutions that can support body composition, appetite regulation, and overall metabolic health in general. “
Mechanism of action
The Slimbiotics postbiotic formula is derived from a probiotic Limosilactobacillus fermentum strain K8-Lb1 isolated, among others, from Kimere, a spontaneously fermented pearl millet dough common in Kenya.
The postbiotic strain has previously been found to confer anti-inflammatory effects on the host. Low-grade inflammation and inflammation-associated endotoxin Lipopolysaccharides (LPS) tend to influence the production of orexigenic agents such as ghrelin, which increases appetite and food intake, as well as anorexigenic agents such as leptin and insulin, which reduce appetite and suppress food intake.
L. fermentum strains contain the chaperone protein ClpL, which seems to operate through mechanisms similar to ClpB, which mimics α-MSH, a molecule involved in controlling appetite, thereby helping to reduce food intake and induce weight loss, the authors wrote.
The study
Sixty female and male overweight individuals (BMI 25 to 32) were randomized into two groups. One group (n = 30) received the Postbiotic (heat-killed L. fermentum strain K8-Lb1) and the other (n = 30) received a placebo.
The study design required participants to complete questionnaires and assess body weight, body fat mass, visceral fat mass, muscle mass, arterial blood pressure and resting heart rate at home at weekly intervals. They also attended their local Quest Diagnostics for blood tests and for measuring waist circumference before and at the end of the intervention period.
After a 12-week intervention, body fat mass was significantly reduced in the postbiotic group compared to the placebo group. In line with this, body weight and waist circumference were significantly reduced and visceral fat tended to be reduced. The postbiotic group also tended to feel more in control of their body weight and their muscle mass tended to increase.
In the postbiotic group, enzymes Alanine transaminase (ALT), Aspartate transferase (AST) and Gamma-glutamyl transferase (GGT) tended to reduce, indicating an improvement in liver steatosis, according to the report.
Further, a reduction in HbA1c (average blood glucose over 2-3 months) and eAG (estimated average glucose) was observed in the postbiotic participants with normal glucose levels before and after intervention. The supplemented group’s ability to concentrate also significantly improved.
“This marks another breakthrough for our company, one of the first significant human studies on a postbiotic of this kind,” said Helmut Essl, Slimbiotics CEO. “It lays the foundation for a highly promising future, not only in the dietary supplement space but also across the broader food and beverage market.”
Study limitations noted in the report include the small number of participants per group, the use of self-assessment measures, and the lack of diet of exercise monitoring. The results therefore need confirmation by a pivotal trial.
Source: Nutrients, “A Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Effect of Limosilactobacillus fermentum K8-Lb1 Postbiotic on Weight Management and Metabolic Health Outcomes”, https://doi.org/10.3390/nu18081174, Authors: Papazova, E.; Mitschke, S.; Laue, C.; Schrezenmeir, J.
