A 12-week randomized controlled trial found that Weissella confusa WIKIM51 probiotic supplementation significantly reduced triglyceride levels and decreased belly fat in overweight adults. According to Gram Research analysis, the probiotic works by triggering release of GLP-1, a hormone that regulates appetite and blood sugar. Participants taking 1 billion colony-forming units daily showed measurable reductions in visceral fat, subcutaneous fat, and total abdominal fat area compared to placebo, with no serious side effects reported.
Researchers tested a specific probiotic called Weissella confusa WIKIM51 (Wilac D001) to see if it could help people lose weight and improve their metabolism. In a 12-week study with overweight adults, those who took the probiotic daily showed significant reductions in triglycerides (a type of fat in the blood) and decreases in belly fat compared to those taking a placebo. The probiotic appears to work by triggering the release of a hormone called GLP-1, which helps regulate appetite and blood sugar. This Gram Research analysis suggests that specific probiotics might offer a new way to support metabolic health alongside diet and exercise.
Key Statistics
A 12-week randomized controlled trial published in the Journal of Microbiology and Biotechnology found that Weissella confusa WIKIM51 probiotic supplementation significantly reduced triglyceride levels and decreased both visceral and subcutaneous fat in overweight adults aged 19 to 64 years.
Laboratory research showed that Wilac D001 probiotic significantly increased GLP-1 secretion in intestinal cells compared to control conditions, suggesting a mechanism by which the probiotic may regulate appetite and blood sugar metabolism.
In mice fed a high-fat diet, Wilac D001 supplementation for 10 weeks improved glucose tolerance, indicating the probiotic’s metabolic benefits extend across different species and may help prevent blood sugar dysregulation.
The 12-week clinical trial reported no serious adverse events in participants taking the Weissella confusa WIKIM51 probiotic at a daily dose of 1.0 billion colony-forming units, demonstrating good safety and tolerability.
The Quick Take
- What they studied: Whether a specific probiotic strain could improve metabolism, reduce belly fat, and lower blood fat levels in overweight people
- Who participated: Overweight adults between ages 19 and 64 years old who received either the probiotic supplement or a placebo pill for 12 weeks
- Key finding: People taking the probiotic showed significant reductions in triglycerides and decreases in both visceral fat (deep belly fat) and subcutaneous fat (fat under the skin) compared to the placebo group
- What it means for you: This probiotic may help support weight management efforts, but it works best combined with healthy eating and exercise. Results typically take several weeks to become noticeable, and individual results vary
The Research Details
This was a randomized controlled trial, which is one of the strongest types of scientific studies. Researchers divided overweight adults into two groups: one received the probiotic Wilac D001 at a dose of 1.0 billion colony-forming units daily, while the other group received an identical-looking placebo pill. Neither the participants nor the researchers knew who was getting the real probiotic until the study ended, which prevents bias from affecting the results.
Before testing in humans, the researchers first studied how the probiotic worked in laboratory cells and in mice fed a high-fat diet. They discovered that the probiotic triggered the release of a hormone called GLP-1, which helps control appetite and blood sugar levels. This finding suggested a possible mechanism for how the probiotic might help with weight management.
During the 12-week trial, researchers measured multiple health markers including blood triglycerides, blood sugar control, belly fat distribution, overall body composition, and body weight. They also tracked lifestyle factors like diet and exercise to ensure the groups were comparable.
Using a randomized, double-blind, placebo-controlled design is important because it eliminates bias and shows whether the probiotic itself causes the changes, not just the expectation of improvement. Testing the mechanism in cells and animals first helps explain how the probiotic might work in humans. Measuring multiple markers of metabolic health gives a complete picture of the probiotic’s effects beyond just weight loss.
This study has several strengths: it used a rigorous double-blind design, included a placebo control group, measured multiple health markers, and reported no serious side effects. The study was published in a peer-reviewed scientific journal. However, the exact number of participants was not specified in the abstract, which makes it harder to assess the statistical power of the findings. Longer-term studies would help determine if benefits persist beyond 12 weeks
What the Results Show
The probiotic group showed significant reductions in triglycerides, which are a type of fat in the blood that increases heart disease risk when elevated. Participants also experienced measurable decreases in total abdominal fat area, visceral fat area (the dangerous deep belly fat surrounding organs), and subcutaneous fat area (fat just under the skin).
The mechanism appears to involve GLP-1, a hormone that helps regulate appetite and blood sugar. In laboratory tests, the probiotic significantly increased GLP-1 secretion compared to controls. This suggests the probiotic works by changing the gut environment in ways that encourage the body to release more of this beneficial hormone.
In mice fed a high-fat diet, the probiotic improved glucose tolerance, meaning their bodies handled blood sugar more effectively. This improvement in glucose control was also observed in the human trial, suggesting the probiotic helps regulate blood sugar across different species.
No serious adverse events were reported during the 12-week study period, indicating the probiotic was well-tolerated by participants.
Beyond the primary findings, the probiotic appeared to improve overall metabolic health markers. The improvements in fat distribution are particularly important because visceral fat (belly fat) is more strongly linked to heart disease and diabetes than fat stored elsewhere on the body. The fact that the probiotic reduced both visceral and subcutaneous fat suggests it affects fat storage throughout the body. Improvements in glucose tolerance indicate the probiotic may help prevent or manage type 2 diabetes risk.
This research builds on growing evidence that gut bacteria influence metabolism and weight. Previous studies have shown that probiotics can affect the composition of gut bacteria and influence metabolic health, but most have tested different strains or studied shorter time periods. This study is notable for identifying a specific mechanism (GLP-1 activation) that explains how this particular probiotic strain works. The 12-week duration is longer than many probiotic studies, allowing time for meaningful changes to develop.
The study abstract does not specify the total number of participants, making it difficult to assess whether the sample size was large enough to detect real effects. The study lasted only 12 weeks, so we don’t know if benefits continue longer or if they fade over time. The study included only overweight adults aged 19 to 64, so results may not apply to obese individuals, older adults, or people with existing metabolic diseases. The study measured changes in fat distribution but didn’t track whether participants actually lost weight overall. Individual responses to probiotics vary greatly, so some people may benefit more than others
The Bottom Line
If you are overweight and interested in supporting your metabolic health, this probiotic may be worth discussing with your doctor. However, it should complement, not replace, a healthy diet and regular exercise. The evidence is moderately strong for improvements in triglycerides and belly fat reduction, but individual results vary. Start with the studied dose of 1 billion colony-forming units daily and give it at least 8 to 12 weeks to see results. This is not a substitute for medical treatment if you have diabetes or high cholesterol
This research is most relevant for overweight adults without serious metabolic diseases who want to support their weight management efforts. People with type 2 diabetes, heart disease, or those taking medications should consult their doctor before starting any probiotic supplement. The study focused on adults aged 19 to 64, so results may not apply to teenagers or older adults. People with compromised immune systems should be cautious with any probiotic supplement
Based on the 12-week study, you should expect to wait at least 8 to 12 weeks before seeing meaningful changes in belly fat or blood triglycerides. Some people may notice improvements in digestion or energy levels sooner, but metabolic changes take time. Continuing the supplement beyond 12 weeks may produce additional benefits, but this hasn’t been studied yet
Frequently Asked Questions
Can probiotics help you lose belly fat?
Research shows that specific probiotic strains like Weissella confusa WIKIM51 may reduce belly fat by triggering GLP-1 hormone release, which regulates appetite. A 12-week trial found significant reductions in visceral and subcutaneous fat, though results vary by individual and work best with diet and exercise.
How long does it take for probiotics to work for weight loss?
Based on the 12-week study, expect to wait 8 to 12 weeks before seeing meaningful changes in belly fat or blood triglycerides. Some people notice digestive improvements sooner, but metabolic changes require consistent daily supplementation over several weeks.
What is GLP-1 and why does it matter for weight management?
GLP-1 is a hormone that controls appetite, slows stomach emptying, and helps regulate blood sugar levels. The probiotic studied increases GLP-1 production in the gut, which may help reduce hunger and improve metabolic health, similar to how GLP-1 medications work.
Is Weissella confusa WIKIM51 probiotic safe to take daily?
The 12-week clinical trial reported no serious adverse events in participants taking the probiotic at 1 billion colony-forming units daily. However, people with compromised immune systems or serious health conditions should consult their doctor before starting any probiotic supplement.
Do probiotics work for everyone or just some people?
Individual responses to probiotics vary significantly because everyone has different gut bacteria composition and genetics. While the study showed group-level improvements in triglycerides and belly fat, some people may benefit more than others. Results work best when combined with healthy eating and exercise.
Want to Apply This Research?
- Log your daily probiotic intake and measure your waist circumference weekly. Track triglyceride levels through blood tests every 4 weeks if possible. Note any changes in energy, digestion, or appetite
- Set a daily reminder to take the probiotic at the same time each day, ideally with a meal. Pair this habit with logging one healthy meal choice daily and recording 30 minutes of physical activity to maximize metabolic benefits
- Create a 12-week tracking plan that includes weekly waist measurements, daily supplement adherence, weekly weight checks, and monthly notes on energy levels and digestion. Schedule blood work at weeks 0, 6, and 12 to monitor triglycerides and glucose control if your doctor recommends it
This research describes the effects of a specific probiotic strain in a 12-week study and should not be considered medical advice. Probiotics are not regulated by the FDA in the same way as medications. Before starting any probiotic supplement, especially if you have diabetes, heart disease, a compromised immune system, or take medications, consult your healthcare provider. This probiotic is not a substitute for medical treatment or lifestyle changes like diet and exercise. Individual results vary, and longer-term safety and effectiveness beyond 12 weeks have not been established. Always inform your doctor about supplements you are taking.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.