Lactobacillus gasseri
Useful mainly for people wanting a strain-specific probiotic for modest visceral-fat reduction or as an adjunct in H. pylori care.
Quick decision guide
May help most
People wanting a strain-specific probiotic for modest visceral-fat reduction or as an adjunct in H. pylori care
Common dosing range
1–10 billion CFU/day
When to expect effects
Weeks (8–12 weeks for weight outcomes)
Watch out for
Small bacteremia risk in immunocompromised or critically ill people
What is it
Lactobacillus gasseri is a probiotic bacterium found naturally in the human gut, mouth, and vagina. It has been studied for weight management, women's health, and gastrointestinal applications, with several specific strains commercially available.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
abdominal and visceral fat reduction Limited Evidence | Small reductions in visceral fat | Adults with excess abdominal fat using a studied strain (BNR17, SBT2055) with diet | Weeks (often 12) |
helicobacter pylori suppression (adjunct) Limited Evidence | Modest improvement in eradication or tolerability | Adults undergoing H. pylori eradication therapy | Weeks (during the treatment course) |
vaginal flora support Limited Evidence | Modest, preliminary | Women aiming to maintain healthy vaginal flora, often as an adjunct to treatment | Weeks |
abdominal and visceral fat reduction
- Effect
- Small reductions in visceral fat
- Best fit
- Adults with excess abdominal fat using a studied strain (BNR17, SBT2055) with diet
- Time
- Weeks (often 12)
helicobacter pylori suppression (adjunct)
- Effect
- Modest improvement in eradication or tolerability
- Best fit
- Adults undergoing H. pylori eradication therapy
- Time
- Weeks (during the treatment course)
vaginal flora support
- Effect
- Modest, preliminary
- Best fit
- Women aiming to maintain healthy vaginal flora, often as an adjunct to treatment
- Time
- Weeks
Evidence for 3 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
abdominal and visceral fat reduction
Supplement benefitTrials of specific strains such as BNR17 and SBT2055 show small reductions in visceral and abdominal fat over about 12 weeks, possibly via effects on fat absorption and appetite hormones. Effect sizes are modest, regain can occur after stopping, and results are strain-specific.
Bottom line: A modest, strain-specific adjunct for abdominal fat, not a substitute for diet and exercise.
Evidence is mixed
Benefits appear in particular strains and trials but are small and not consistently reproduced.
helicobacter pylori suppression (adjunct)
Disease adjunctAs an adjunct to standard eradication regimens, some L. gasseri-containing probiotics may modestly improve eradication rates or reduce antibiotic-related side effects. Evidence is limited and mixed across strains and protocols.
Bottom line: A possible adjunct to standard H. pylori therapy, not a standalone treatment.
vaginal flora support
Supplement benefitL. gasseri is a dominant species in healthy vaginal flora and may help maintain a low-pH, lactic-acid environment that resists pathogen overgrowth. Clinical evidence is limited and strain-dependent.
Bottom line: Plausible and preliminarily supportive for vaginal flora, but evidence is thin.
How it works
How to take it
What to track
3 commercial forms
Compare the main delivery options and what they’re best suited for.
L. gasseri SBT2055
Most-studied strain for fat-reduction outcomes. Used in fermented dairy products and supplements in Japan.
Studied at low doses (~100 million CFU) for weight effects
L. gasseri BNR17
Studied for weight management and menstrual health applications.
Acid-stable, isolated from human breast milk
L. gasseri CUL-09
Common in supplement formulations targeting women's health.
Used in multi-strain blends
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
Rare bacteremia in immunocompromised or critically ill people
Who should avoid it
- Severely immunocompromised people
- People with central venous catheters
- Critically ill patients (without physician input)
Pregnancy & breastfeeding
Generally well tolerated in pregnancy and breastfeeding, but confirm strain and check for dairy carriers if allergic.
Interactions
Can kill the probiotic; separate doses by at least 2 hours
May raise the small risk of bacterial translocation
Food sources
| Food | Amount | %DV |
|---|---|---|
| Some fermented dairy (Japanese-market products) | Variable; specific strains in branded products | — |
| Human breast milk | Natural source, particularly for BNR17 | — |
Some fermented dairy (Japanese-market products)
- Amount
- Variable; specific strains in branded products
- %DV
- —
Human breast milk
- Amount
- Natural source, particularly for BNR17
- %DV
- —
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
Be skeptical of…
Frequently asked questions
Can L. gasseri really help me lose weight?⌄
Trials show small reductions in abdominal and visceral fat (typically 1 to 4 percent) over 8 to 12 weeks. It is not a substitute for diet and exercise but may modestly support fat-reduction efforts in some people.
Which L. gasseri strain is best for weight?⌄
SBT2055 has the most research on fat-related outcomes. BNR17 has also been studied. Look for specific strain designations on labels.
Is L. gasseri safe in pregnancy?⌄
L. gasseri is generally well tolerated in pregnancy, but discuss with your obstetric provider before starting any supplement during pregnancy.
Can L. gasseri help with vaginal health?⌄
It is a normal inhabitant of healthy vaginal flora. Some trials suggest oral or vaginal supplementation may support recovery from bacterial vaginosis when combined with standard treatment.
How long should I take L. gasseri before judging effects?⌄
For weight-related outcomes, trials typically run 8 to 12 weeks. For digestive or vaginal health, effects may be seen within a few weeks.
References by claim
Track Lactobacillus gasseri with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.