Short answer: Two 12-week randomised human trials have measured Lactobacillus gasseri BNR17® on body fat. In Kim et al. 2018 (n = 90, CT scan), the 10 billion CFU group had 21.6 cm² less visceral fat than placebo. In Jung et al. 2013 (n = 57), waist fell 2.0 cm, hip 2.8 cm and BMI 0.5 from baseline. Body weight did not differ significantly from placebo in either trial. Individual results may vary.
Imagine two colleagues taking the same LRT into the city every morning. They buy lunch from the same row of economy rice stalls and go to the same 6pm gym class three times a week.
One has a waist that has gradually pushed past 90cm. The other still fits into jeans from five years ago.
You might assume the first person has the bigger body-fat problem. A scan could show the opposite.
Some people who look relatively lean carry more fat around the liver, pancreas and intestines than people who appear heavier. This is visceral fat. It is one reason body weight alone can be a poor guide to what is happening inside the body.
Malaysia’s own health data makes the issue difficult to ignore. The 2023 National Health and Morbidity Survey reported abdominal obesity in 54.5% of Malaysian adults. Unlike BMI, abdominal obesity is assessed using waist circumference, so it can pick up changes that a bathroom scale may not.
Why Diet and Exercise Sometimes Stop Showing Up on the Scale
For many office workers, the first few months of eating smaller portions or exercising more produce obvious results. Weight drops. Clothes fit differently. Then progress slows.
That does not necessarily mean nothing is changing.
Body weight and visceral fat are not the same measure. Someone can stay at roughly the same weight for years while fat distribution changes. A person can also look slim and still carry a relatively high amount of fat around the abdominal organs.
This pattern is sometimes called TOFI, short for “thin outside, fat inside.”
[Why waist size can hide more than it reveals →]Food intake and physical activity still matter most, and five everyday habits do most of the work. But they are not the only areas researchers are studying. One increasingly active field looks at whether the gut microbiome may influence how the body regulates appetite, inflammation and fat storage.
What Gut Bacteria Have to Do With Visceral Fat
The digestive tract contains trillions of microorganisms. Together, they make up the gut microbiome.
Research suggests that gut microbes can influence short-chain fatty acid production, inflammatory signalling and hormones involved in appetite and energy regulation. Differences in gut microbial composition have also been associated with obesity and abdominal fat in both animal and human research.
That does not mean any probiotic will produce the same effect (here is how to test a fat loss probiotic claim).
Probiotic research is highly strain-specific. A result found with one strain cannot simply be applied to another strain, even if both belong to the same bacterial species.
That distinction matters when looking at Lactobacillus gasseri BNR17®.
What the Human Trials on BNR17® Actually Found
Lactobacillus gasseri BNR17® is a probiotic strain originally isolated from human breast milk and developed through research in South Korea.
Two randomised controlled human trials are central to the evidence.
The first, published in the Korean Journal of Family Medicine in 2013, followed adults with obesity for 12 weeks (57 completed the study). Participants were not placed on a controlled diet or exercise programme.
Waist circumference decreased within the BNR17® group, while the placebo group did not show the same change. However, the difference in visceral fat area between the BNR17® and placebo groups was not statistically significant.
So the result was interesting, but limited.
A second trial, published in the Journal of Medicinal Food in 2018, enrolled 90 overweight and obese adults. Participants received placebo, low-dose BNR17® or high-dose BNR17® for 12 weeks. They also received mild guidance on energy intake.
In this study, the high-dose BNR17® group showed a statistically significant reduction in visceral adipose tissue compared with placebo. Waist circumference also decreased from baseline in both BNR17® groups.
The study did not show significant between-group improvements in measures such as blood glucose.
The context matters. The clearer visceral-fat result appeared in a trial where participants also received dietary guidance. It would therefore be inaccurate to present BNR17® as working independently of diet or lifestyle.
The effects were also modest. That is more consistent with what you would expect from a strain-specific probiotic study than from the way weight-management products are often advertised.
Why This Is Especially Relevant in Malaysia and Singapore
Asian populations can develop metabolic risk at lower BMI levels than many Western populations. This is one reason lower BMI and waist-circumference thresholds are commonly used when assessing risk in Asian adults.
For Asian populations, waist measurements above 90cm in men and 80cm in women are commonly used as thresholds for increased metabolic risk.
That makes visceral fat particularly easy to overlook in someone who does not appear overweight.
A person may exercise regularly, look reasonably lean and still spend most of the working day sitting. Sleep, total energy intake, genetics, alcohol intake and other lifestyle factors can all affect body composition.
You cannot tell how much visceral fat someone carries simply by looking at them.
That is the real blind spot.
Where BNRThin Slim+ Fits
BNRThin Slim+ contains Lactobacillus gasseri BNR17® at 10 billion CFU per daily serving, matching the daily dose used in the high-dose arm of the 2018 study.
It comes as a 2 g powder stick that melts in the mouth, with no water needed.
The most sensible way to use it is alongside the same habits that already matter for body composition: reasonable food portions, regular movement, exercise and adequate sleep.
The human studies lasted 12 weeks, so BNR17® is not something that should be judged after a few days or one box.
It is also not a substitute for the basics.
A better way to think about it is as an additional, evidence-based layer for people already working on body composition and abdominal fat.
[Full product details on BNRThin Slim+ →]
Frequently Asked Questions
Does BNR17® make you lose weight?
The available research does not support describing BNR17® as a standalone weight-loss treatment.
The clinical studies focused on measures such as waist circumference and visceral adipose tissue. The stronger visceral-fat result came from the 2018 trial, where participants also received modest dietary guidance.
How long does BNR17® take to work?
The two main human trials lasted 12 weeks. That is the timeframe in which the reported changes were measured.
Individual responses vary, and the research does not establish what should be expected from much shorter periods of use.
Is BNR17® safe to take with medication or during pregnancy?
The studies discussed here were conducted in general adult populations. They do not establish safety for every medical situation.
If you are pregnant, breastfeeding, taking prescription medication or managing a chronic condition, speak with a doctor or pharmacist before starting a new supplement.
What makes BNR17® different from other probiotics sold for weight management?
The main difference is that the evidence is strain-specific.
The findings from BNR17® studies apply to Lactobacillus gasseri BNR17® at the doses and conditions studied. They should not be assumed to apply to every Lactobacillus gasseri strain or to probiotics in general.
Where does Lactobacillus gasseri BNR17® come from?
BNR17® is a patented strain originally isolated from human breast milk and developed through research in South Korea. It has since been studied in randomised controlled human trials examining body-composition outcomes.
Go back to the two colleagues on the LRT.
The person with the larger waist is easy to identify. The leaner colleague is harder to read because appearance says very little about where fat is stored.
That is why watching body weight alone can miss part of the picture.
And it is the more accurate way to understand where BNR17® fits: not as a shortcut to weight loss, but as one possible tool within a longer-term approach to improving body composition.
This article is for general educational purposes and is not medical advice. BNR17® is a dietary supplement studied in controlled human trials for body-composition outcomes including visceral adipose tissue and waist circumference. It is not intended to diagnose, treat, cure or prevent any disease. Individual results vary. Consult a healthcare professional before starting a new supplement if you are pregnant, breastfeeding, taking medication or managing a medical condition.
New to BNR17®? Start with the science behind BNR17®.
Questions people ask
How many human trials has BNR17® had?
Four. Two 12-week trials measured body fat (Jung et al. 2013 and Kim et al. 2018). Two more looked at gut comfort and at whether the strain reaches the gut alive; in one, BNR17® was found in the stool of 26 of 30 people who took it and none of 12 on placebo.
What dose of BNR17® was used in the visceral fat trial?
10 billion CFU a day for 12 weeks. That is the amount in one BNRThin Slim+ sachet.
Did body weight change in the BNR17® trials?
Body weight did not differ significantly from placebo. The measured changes were 21.6 cm² less visceral fat than placebo by CT scan, and waist, hip and BMI down from baseline.