Bifidobacterium bifidum
Also called B. bifidum, MIMBb75, G9-1, BGN4, BBi32, Bf-688.
Best grade B across 7 graded outcomes Other Last checked
The short answer
From 12 sourcesBifidobacterium bifidum is a probiotic bacterium whose effects are strain-specific. One strain, MIMBb75, eased IBS symptoms in two randomized trials, including a 443-person trial of a heat-killed version (grade B). Another strain did not improve constipation quality of life, and a third did not change body fat.
Every graded outcome on this page
7 rows · line = participants- BGrade BAbdominal pain plus adequate relief of IBS symptomsIBSn 443
- BGrade BGlobal IBS symptomsIBSn 122
- CGrade CConstipation quality of lifeConstipationn 140
- CGrade CAttention test performance in children with ADHD on methylphenidateADHDn 102
- CGrade CGastrointestinal symptoms in type 2 diabetesGut symptomsn 94
- DGrade DInflammation (hs-CRP), body fat and metabolic markersWeightn 58
- DGrade DSafety, tolerability and gut symptom scoresSafetyn 40
- 4 more graded outcomes, in the evidence chapter
Key facts
- What it is
- A Bifidobacterium species sold as single strains (MIMBb75, G9-1, BGN4, BBi32, Bf-688) or in blends1345
- IBS
- MIMBb75 raised responder rates versus placebo: 57% vs 21% (live, 122 people) and 34% vs 19% (heat-killed, 443 people)12
- Constipation
- G9-1 did not improve the main constipation quality-of-life score over 8 weeks in 140 adults3
- Gut symptoms in type 2 diabetes
- G9-1 for 12 weeks lowered gastrointestinal symptom scores 0.34 points more than no supplement in 94 adults with type 2 diabetes and diarrhoea or constipation (open-label)9
- Weight
- BGN4 did not change BMI, body fat or hs-CRP over 8 weeks in 58 adults4
- Retracted trial
- A 2024 trial of B. bifidum in babies born by cesarean section was retracted6
What it is
Bifidobacterium bifidum is a gut bacterium common in breastfed infants and sold as a probiotic; effects depend on the strain.
How it works
ProposedB. bifidum lives in the gut and is common in breastfed infants. In IBS, the heat-killed MIMBb75 strain worked without being alive, which suggests effects from contact with the gut lining rather than from colonizing it. In adults with excess body fat, BGN4 changed stool bacteria and lowered zonulin, a proposed marker of gut permeability.24
Forms, side by side
2 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.
Bifidobacterium bifidum forms compared
2 forms| 2 forms | Live B. bifidum (capsules or powder) | Heat-inactivated B. bifidum MIMBb75 |
|---|---|---|
| Absorption in people | Not absorbed; probiotics act in the gut, and BGN4 shifted stool bacteria in the adiposity trial.4 | Not absorbed; the cells are dead and act in the gut.2 |
| GI tolerance | Adverse events did not differ from placebo at 4 to 8 weeks in the cited trials.135 | No serious adverse events; 91% rated tolerability good or very good.2 |
| Studied for | IBS, constipation, adiposity markers and safety | IBS |
- Live B. bifidum (capsules or powder)
- Absorption in people
- Not absorbed; probiotics act in the gut, and BGN4 shifted stool bacteria in the adiposity trial.4
- Studied for
- IBS, constipation, adiposity markers and safety
- Heat-inactivated B. bifidum MIMBb75
What the human research says
Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.
Trial map
7 graded outcomes, largest study first7 graded outcomes: 4 improved, 2 mixed, 1 no effect. The largest, a 2020 randomized trial of 443 people on abdominal pain plus adequate relief of IBS symptoms, found an improvement.
1Abdominal pain plus adequate relief of IBS symptoms
Improved · Grade B · RCT, 443 people, 2020
Adults with IBS (Rome III) at 20 sites in Germany
Dose, result and source| Outcome | Found | People | Study | Who was studied |
|---|---|---|---|---|
| Abdominal pain plus adequate relief of IBS symptoms | Improved | 443 | Grade B · RCT, 2020 | Adults with IBS (Rome III) at 20 sites in Germany |
| Constipation quality of life | No effect | 140 | Grade C · RCT, 2026 | Adults with chronic constipation (Japan) |
| Global IBS symptoms | Improved | 122 | Grade B · RCT, 2011 | Adults with IBS |
| Attention test performance in children with ADHD on methylphenidate | Mixed | 102 | Grade C · RCT, 2024 | Children with ADHD already on a stable dose of methylphenidate |
| Gastrointestinal symptoms in type 2 diabetes | Improved | 94 | Grade C · RCT, 2026 | Adults with type 2 diabetes and diarrhoea or constipation |
| Inflammation (hs-CRP), body fat and metabolic markers | Mixed | 58 | Grade D · RCT, 2026 | Adults with excess body fat |
| Safety, tolerability and gut symptom scores | Improved | 40 | Grade D · RCT, 2026 | Adults (China) |
Every graded row
7 rowsShowing 7 of 7 outcomes. Human trials only.
BGrade BAbdominal pain plus adequate relief of IBS symptomsIBSImprovedRCT
n 443 · 2020
Improved 34% reached the combined endpoint of at least 30% less pain plus adequate relief in 4 of 8 weeks, versus 19% on placebo (risk ratio 1.7). Suspected product-related adverse events were similar (7 vs 8), with no serious ones.
- Design
- RCT, n = 443, 2020
- Population
- Adults with IBS (Rome III) at 20 sites in Germany
- Form
- Heat-inactivated (non-viable) B. bifidum MIMBb75
- Dose
- 1 billion cells a day
- Duration
- 8 weeks
- Source
- Reference 2 · PubMed 32277872 (opens PubMed)
BGrade BGlobal IBS symptomsIBSImprovedRCT
n 122 · 2011
Improved Global IBS symptoms fell 0.88 points on a 7-point scale versus 0.16 with placebo. Adequate relief: 47% vs 11%; responders: 57% vs 21%. Pain, bloating and urgency also improved, and adverse events did not differ.
- Design
- RCT, n = 122, 2011
- Population
- Adults with IBS
- Form
- B. bifidum MIMBb75 (live)
- Dose
- Once daily (CFU not stated in the abstract)
- Duration
- 4 weeks
- Source
- Reference 1 · PubMed 21418261 (opens PubMed)
CGrade CConstipation quality of lifeConstipationNo effectRCT
n 140 · 2026
No effect The main constipation quality-of-life score did not differ from placebo (p = 0.28). A physical-discomfort subscale improved nominally (p = 0.041). No adverse events were reported.
- Design
- RCT, n = 140, 2026
- Population
- Adults with chronic constipation (Japan)
- Form
- B. bifidum G9-1
- Dose
- Not stated in the abstract
- Duration
- 8 weeks
- Source
- Reference 3 · PubMed 41843723 (opens PubMed)
CGrade CAttention test performance in children with ADHD on methylphenidateADHDMixedRCT
n 102 · 2024
Mixed Only the Bf-688 group improved from baseline in omission errors and hit reaction time on computerised attention tests. Parent- and clinician-rated ADHD symptom scores fell in both groups with similar patterns.
- Design
- RCT, n = 102, 2024
- Population
- Children with ADHD already on a stable dose of methylphenidate
- Form
- B. bifidum Bf-688 (add-on to medication)
- Dose
- 5 × 10⁹ CFU a day
- Duration
- 12 weeks
- Source
- Reference 10 · PubMed 39064703 (opens PubMed)
CGrade CGastrointestinal symptoms in type 2 diabetesGut symptomsGSRS −0.34 vs controlRCT
n 94 · 2026
Improved Total GSRS symptom score fell from 2.22 to 1.83 with G9-1 versus 2.08 to 2.06 in controls (between-group difference −0.34 on a 1–7 scale; 95% CI −0.55 to −0.14). The constipation subscale fell more (−0.79 vs −0.13). Adverse effects were similar.
- Design
- RCT, n = 94, 2026
- Population
- Adults with type 2 diabetes and diarrhoea or constipation
- Form
- B. bifidum G9-1
- Dose
- 12 mg of Bifidobacterium a day
- Duration
- 12 weeks
- Source
- Reference 9 · PubMed 42017290 (opens PubMed)
DGrade DInflammation (hs-CRP), body fat and metabolic markersWeightMixedRCT
n 58 · 2026
Mixed The primary outcome hs-CRP, BMI and body fat did not change. Zonulin, TNF-alpha and fasting insulin fell versus placebo.
- Design
- RCT, n = 58, 2026
- Population
- Adults with excess body fat
- Form
- B. bifidum BGN4
- Dose
- 9 billion CFU a day
- Duration
- 8 weeks
- Source
- Reference 4 · PubMed 42116047 (opens PubMed)
DGrade DSafety, tolerability and gut symptom scoresSafetyImprovedRCT
n 40 · 2026
Improved Well tolerated with no blood count or liver abnormalities; gastrointestinal symptom scores improved and urea, uric acid and creatinine fell versus placebo.
- Design
- RCT, n = 40, 2026
- Population
- Adults (China)
- Form
- B. bifidum BBi32
- Dose
- 30 billion CFU a day
- Duration
- 8 weeks
- Source
- Reference 5 · PubMed 41523287 (opens PubMed)
What the numbers add up to
Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.
A killed probiotic worked
The largest B. bifidum trial used dead bacteria and still beat placebo for IBS, which argues against assuming live counts are what matter for every strain.2
Two newer trials missed their main outcomes
Studied doses
Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.
Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.
Doses studied in human trials
Doses studied in human trials ranged from 1 billion heat-inactivated cells a day of MIMBb75 for 8 weeks (IBS) to 9 billion CFU a day of BGN4 and 30 billion CFU a day of BBi32 for 8 weeks; Bf-688 was given at 5 billion CFU a day and G9-1 at 12 mg a day for 12 weeks, and the live MIMBb75 IBS trial gave one dose a day for 4 weeks.1245910
Interactions and safety
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
What Bifidobacterium bifidum meets
1 cited row 1 tested togetherMedicines 1
Supplements and foods 1
- Drug label or FDA notice
- Tested together in a graded trial
Choose a medicine or supplement above to read its cited rows here.
Also cited: 1 tested together
Antibiotics
Drug labelDrug label or FDA notice
Antibiotics, for example any oral antibiotic course: Health Canada's probiotic monograph requires labels for bacterial probiotics, including B. bifidum, to direct use at least 2–3 hours before or after antibiotics.
Source 12, Health Canada, Natural and Non-prescription Health Products Directorate (2026)
Lactobacillus gasseriLactobacillus gasseri page
Tested together
Seasonal allergy quality of life. Graded on the Lactobacillus gasseri page; tested together is not a claim that they work better together.
Interactions
1 agent| Agent | What the source says | Evidence |
|---|---|---|
| Medicines1 | ||
| Antibioticse.g. any oral antibiotic course | Health Canada's probiotic monograph requires labels for bacterial probiotics, including B. bifidum, to direct use at least 2–3 hours before or after antibiotics.12 | Drug label |
Check with what you take
Kept on this device onlyAdd what you take. We list every interaction our evidence profiles cite between Bifidobacterium bifidum and your picks, and between your picks.
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Add a supplement or medicine you take to check it against Bifidobacterium bifidum.
Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.
Who should be careful
4 groups- Preterm infants
- FDA warned that probiotics with live bacteria given to preterm infants have caused invasive, sometimes fatal infections.7
- Weakened immune system or serious illness
- NCCIH notes that probiotics can cause serious infections in people with severe illness or weakened immune systems.8
- Pregnancy, breastfeeding and children
- LactMed has no probiotic entry. In a randomized trial of strain PRL2010, given from week 36 of pregnancy through breastfeeding to mothers with atopy or a family history of atopy, no severe adverse effects from the probiotic were reported; the other cited trials enrolled non-pregnant adults. In children, Bf-688 was tested only alongside ADHD medication.111012
- Immune-compromised conditions
- Health Canada's probiotic monograph: do not use with an immune-compromised condition (for example AIDS, lymphoma or long-term corticosteroid treatment).12
How to read the label
What to check on the Supplement Facts panel.
How to read the label
2 checksCheck the strain
Live vs heat-killed
The 443-person IBS trial used non-viable, heat-inactivated cells, so a live CFU count is not the measure for that product.2
Frequently asked questions
Short answers to common questions; the numbers link to the sources below.
Common questions
8 answersDoes Bifidobacterium bifidum help IBS?
Does B. bifidum help constipation?
The G9-1 strain did not improve the main constipation quality-of-life score in a 140-person, 8-week trial.3
Does B. bifidum help ADHD?
Not shown. In 102 children already on methylphenidate, Bf-688 (5 billion CFU a day for 12 weeks) improved some computer attention-test scores within its own group, but parent- and clinician-rated ADHD symptoms improved similarly with placebo (grade C).10
Does B. bifidum help with weight loss?
In 58 adults with excess body fat, BGN4 for 8 weeks did not change BMI or body fat.4
Do all B. bifidum strains work the same?
Is B. bifidum safe?
How long does B. bifidum take to work?
Can B. bifidum be taken with antibiotics?
Health Canada's probiotic monograph says bacterial probiotics should be taken at least 2–3 hours before or after antibiotics. None of the cited B. bifidum trials tested use during an antibiotic course.12
Sources
12 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.
Sources cited on this page
12 sources- 1Randomised clinical trial: Bifidobacterium bifidum MIMBb75 significantly alleviates irritable bowel syndrome and improves quality of life--a double-blind, placebo-controlled study.RCT Aliment Pharmacol Ther, 2011 · PMID 21418261
- 2Heat-inactivated Bifidobacterium bifidum MIMBb75 (SYN-HI-001) in the treatment of irritable bowel syndrome: a multicentre, randomised, double-blind, placebo-controlled clinical trial.RCT Lancet Gastroenterol Hepatol, 2020 · PMID 32277872
- 3Bifidobacterium bifidum G9-1 and Quality of Life in Chronic Constipation: A Multicenter, Double-Blind, Randomized Controlled Trial.RCT Digestion, 2026 · PMID 41843723
- 4Probiotic Bifidobacterium bifidum BGN4 supplementation modulates gut microbiome composition and reduces circulating zonulin, TNFα, and insulin in adults with excess adiposity: a randomized, double-blind, placebo-controlled trial.RCT Nutr Metab (Lond), 2026 · PMID 42116047
- 5Clinical Safety and Tolerability of Bifidobacterium bifidum BBi32: An 8-Week Randomized, Double-Blind, Placebo-Controlled Trial With Genomic and In Vitro Corroboration.RCT Food Sci Nutr, 2026 · PMID 41523287
- 6RETRACTED: Effect of Bifidobacterium bifidum Supplementation in Newborns Born from Cesarean Section on Atopy, Respiratory Tract Infections, and Dyspeptic Syndromes: A Multicenter, Randomized, and Controlled Clinical Trial.RCT Microorganisms, 2024 · PMID 38930475
- 7Risk of Invasive Disease in Preterm Infants Given Probiotics Formulated to Contain Live Bacteria or YeastSafety communication U.S. Food and Drug Administration, 2023 · fda.gov
- 8Probiotics: Usefulness and SafetyFact sheet National Center for Complementary and Integrative Health (NCCIH), 2019 · nccih.nih.gov
- 9Bifidobacterium bifidum G9-1 Intake Improves Gastrointestinal Symptoms in Type 2 Diabetes Mellitus: An Open-Label, Randomized Controlled Trial (Binary STAR Study).RCT Diabetes Obes Metab, 2026 · PMID 42017290
- 10Add-On Bifidobacterium Bifidum Supplement in Children with Attention-Deficit/Hyperactivity Disorder: A 12-Week Randomized Double-Blind Placebo-Controlled Clinical Trial.RCT Nutrients, 2024 · PMID 39064703
- 11Effect of Supplementation with a Specific Probiotic (Bifidobacterium bifidum PRL2010) in Pregnancy for the Prevention of Atopic Dermatitis in Children: Preliminary Results of a Randomized Trial.RCT Nutrients, 2025 · PMID 40005000
- 12Probiotics (Natural Health Product monograph, April 24, 2026)Guideline Health Canada, Natural and Non-prescription Health Products Directorate, 2026 · webprod.hc-sc.gc.ca
What changed
Every dated change to this page: what changed, who made it and why.
Change log
3 entries| Date | Change | Who and why |
|---|---|---|
| evidence, key facts, studied doses, interactions, who should avoid, FAQ, questions, related | Added two strain-named trials: G9-1 for gastrointestinal symptoms in 94 adults with type 2 diabetes (2026, open-label, grade C) and Bf-688 as an add-on in 102 children with ADHD (2024, grade C; n from full text). Added the antibiotic-spacing direction and immune-compromised contraindication from the Health Canada probiotic monograph, and a pregnancy and breastfeeding note citing a PRL2010 pregnancy trial (LactMed has no probiotic entry; LiverTox none). Added FAQ items on ADHD, antibiotics and time to effect, page questions, and the B. breve and gut goal hub links. PubMed searched for B. bifidum RCTs and meta-analyses 2021–2026: multi-strain blends and a retraction-flagged infant trial not added. | Writer: Kymata Health EditorialTrigger: A–Z audit against docs/supplements/AUDIT-STANDARD.md |
| all | First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for every cited row. | Writer: Kymata Health EditorialTrigger: new page |
| all | Adversarial review pass: every evidence row's numbers machine-checked against its PubMed abstract, retraction and erratum flags checked for all PMIDs, unverified country and affiliation details removed, and claims not supported by the cited abstracts reworded or dropped. | Writer: Kymata Health EditorialTrigger: review |
Supplement & Nutrient Encyclopedia. Educational information only; it is not medical advice and does not replace a clinician. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease. Statements about supplements have not been evaluated by the FDA.