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Bi35.0
B. infantis 35624 Research
Mostly mechanism / observational
13 peer-reviewed studies
What the evidence says
Mostly mechanism / observational
Most B. infantis 35624 studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from high-quality meta-analyses and randomised trials published 2005–2026 with a typical study size of 118 participants.
Based on 13 studies · 2 meta-analyses · 5 RCTs · 1,315 total participants
Confidence
High confidence
By outcome
IBS symptoms & abdominal painModest relief of IBS abdominal pain and global symptoms; no established benefit for bloating, gas, or for people without diagnosed IBS · 4 weeks
Mostly mechanism / observational11 studies
Bloating & distension
Mostly mechanism / observational6 studies
Systemic inflammationReduced plasma CRP and other inflammatory markers across several conditions — biomarker changes only, with no clinical outcome demonstrated · 6-8 weeks
Mostly mechanism / observational3 studies
Immune modulation & regulatory T cells
Too few graded studies1 study
Safety profile
Too few graded studies1 study
Active research area
4 studies in the last 5 years · Latest meta-analysis: 2026
200520152026
1RCTn=362 · medium study2006
In plain English: In a 362-patient dose-ranging trial, 100 million CFU beat both placebo and every other dose for abdominal pain — while 10 billion CFU did not.
Whorwell PJ et al. · Am J Gastroenterol (2006)
1 x 10^8 CFU significantly superior to placebo AND to all other doses for the primary endpoint of abdominal pain
Also superior for composite score, bloating, bowel dysfunction, incomplete evacuation, straining and passage of gas
Inverted-U dose response: neither 1 x 10^6 nor 1 x 10^10 CFU beat placebo
In plain English: In the most common consumer scenario — people self-treating discomfort and bloating without a diagnosis — the strain failed its primary endpoint.
Ringel-Kulka T, McRorie J, Ringel Y · Am J Gastroenterol (2017)
No significant difference vs placebo in mean severity of abdominal discomfort or bloating (P>0.3)
Both groups improved significantly, indicating a large placebo effect
One secondary endpoint favoured the probiotic: more bloating-free days (P<0.05)
In plain English: An independent systematic review concluded this was the only probiotic with efficacy shown in two appropriately designed studies, while noting most IBS probiotic trials were poorly designed.
In plain English: The original trial found symptom benefit alongside normalization of an abnormal inflammatory cytokine ratio, an effect the comparator strain did not produce.
O'Mahony L et al. · Gastroenterology (2005)
Beat placebo on composite score and on abdominal pain, bloating/distention and bowel-movement difficulty for most treatment weeks
No benefit on bowel movement frequency or consistency
Comparator strain L. salivarius UCC4331 did NOT show the same benefit, supporting strain specificity
In plain English: This meta-analysis found no effect for the single strain, attributing the pooled benefit instead to multi-strain products that contain it.
Yuan F et al. · Curr Med Res Opin (2017)
Single-strain 35624 had no effect on abdominal pain, bloating/distention, or bowel-habit satisfaction
Composite probiotics containing 35624 did reduce abdominal pain (SMD 0.22, 95% CI 0.03-0.41) and bloating (SMD 0.30, 95% CI 0.04-0.56)
Pooling all six datasets, only bloating remained significant (SMD 0.21, 95% CI 0.07-0.35)
In plain English: A strain-by-strain meta-analysis of randomised placebo-controlled trials lists B. longum (formerly infantis) 35624 among the strains demonstrating efficacy for key IBS symptoms.
Maslennikov R et al. · J Clin Med (2026)
Meta-analyses demonstrated efficacy of Bifidobacterium longum (formerly Bifidobacterium infantis) 35624 in improving key IBS symptoms
Lactobacillus rhamnosus GG, Lactiplantibacillus plantarum 299v, Saccharomyces cerevisiae CNCM I-3856 and Bacillus coagulans Unique IS2 also showed efficacy
Meta-analyses did NOT demonstrate efficacy for E. coli Nissle 1917, L. gasseri BNR17 or L. casei Shirota; results for S. boulardii CNCM I-745 were conflicting
In plain English: We conclude that an 8-week course of B. longum 35624® was associated with significant, clinically meaningful symptom relief in a typical population of adult patients with IBS.
Lenoir M et al. · Probiotics and antimicrobial proteins (2025)
The course of B. longum 35624® was associated with a significant reduction (43.4%) in the TISS vs. baseline.
The effectiveness of B. longum 35624® was rated as "good to satisfactory" by study participants and the investigating physicians.
One mild adverse event (nausea) was potentially linked to the study treatment.
In plain English: The addition of a prolonged course of the probiotic Bifidobacterium longum 35624® to the basic therapy in patients with IBS allows a more pronounced and lasting effect to be achieved.
Solovyeva OI et al. · Terapevticheskii arkhiv (2023)
The addition of the main therapy with a probiotic made it possible to achieve a significant decrease in the severity of abdominal pain, bloating, and stool disorders.
The severity of IBS significantly decreased according to the results of IBS-SSS.
The addition of a prolonged course of the probiotic Bifidobacterium longum 35624® to the basic therapy in patients with IBS allows a more pronounced and lasting effect to be achieved.
In plain English: Thirty days of treatment with B. longum 35624 reduces disease severity and improves the quality of life of patients with IBS, particularly those with the most severe forms of IBS.
Sabaté JM et al. · World journal of gastroenterology (2022)
A total of 233 patients, with a mean age of 51.4 years and composed of 71.2% women, were included in the study.
Of these patients, 48.1% had moderate IBS and 46.4% had severe IBS.
The quality of life of patients was also improved by the treatment (IBS Quality of Life questionnaire score: 68.8 ± 20.9 vs 60.2 ± 20.5; P < 0.001) and 63.8% of patients were satisfied with the treatment.
In plain English: Plasma CRP fell across ulcerative colitis, chronic fatigue and psoriasis cohorts, showing systemic immune effects — though only as biomarkers, with no clinical outcome measured.
Groeger D et al. · Gut Microbes (2013)
Reduced plasma CRP vs placebo in all three inflammatory disorders
Plasma TNF-alpha reduced in chronic fatigue and psoriasis; IL-6 reduced in ulcerative colitis and chronic fatigue
In healthy subjects, LPS-stimulated TNF-alpha and IL-6 from immune cells fell after 8 weeks
In plain English: Feeding this strain to human volunteers selectively increased IL-10 secretion and Foxp3 regulatory T-cell expression in peripheral blood.
Konieczna P et al. · Gut (2012)
Volunteers showed selectively increased IL-10 secretion and enhanced Foxp3 expression in peripheral blood
All three dendritic-cell subsets secreted IL-10 but not IL-12p70 in vitro
Foxp3 induction required TLR-2, DC-SIGN and retinoic acid in myeloid cells, or IDO in plasmacytoid cells
In plain English: Two weeks of Align significantly raised methane excretion on the lactulose breath test, to levels that would be read as positive for SIBO.
Kumar K et al. · Dig Dis Sci (2018)
Methane levels were significantly higher after probiotic administration (p=0.012); hydrogen levels were unchanged (p=0.768)
A rise in methane >20 ppm was seen in 3 subjects pre-probiotic but 6 post-probiotic
An 'abnormal' lactulose breath test was present in 10 of 19 subjects pre-probiotic and 13 of 19 during the probiotic