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Head-to-head evidence comparison — which supplement is right for you?
B. infantis 35624 vs L. casei Shirota: they're closely matched on evidence (5 vs 5/10); they're alternatives for improve digestion — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
B. infantis 35624 and L. casei Shirota are closely matched across evidence, studies, and safety.
Verdict
Mostly mechanism / observational
Top outcomes
Verdict
Mostly mechanism / observational
Top outcomes
Shared outcomes (1)
Outcomes where both B. infantis 35624 and L. casei Shirota have evidence — compare verdict strength side-by-side.
1 x 10^8 CFU (100 million) daily — the dose that won the only head-to-head dose comparison; 1 x 10^10 CFU also beat placebo in a separate trial, so higher doses are not ruled out
any
Freeze-dried capsule standardized to 35624 at 1 x 10^8 CFU
One 65-100 mL bottle of the fermented milk drink daily, delivering roughly 6.5 x 10^9 to 1 x 10^11 CFU depending on the product. Doses across trials span this whole range with no dose-comparison study to separate them.
any
Fermented milk drink containing L. casei Shirota (Yakult), 65-100 mL daily
4 weeks
4 weeks
n/a
n/a
4 weeks
2 weeks
2-12 weeks
8 weeks
Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome.
Am J Gastroenterol (2006) · Rct · n=362
1 x 10^8 CFU significantly superior to placebo AND to all other doses for the primary endpoint of abdominal pain
Lactobacillus and bifidobacterium in irritable bowel syndrome: symptom responses and relationship to cytokine profiles.
Gastroenterology (2005) · Rct · n=77
Beat placebo on composite score and on abdominal pain, bloating/distention and bowel-movement difficulty for most treatment weeks
Efficacy of Bifidobacterium infantis 35624 in patients with irritable bowel syndrome: a meta-analysis.
Curr Med Res Opin (2017) · Meta analysis
Single-strain 35624 had no effect on abdominal pain, bloating/distention, or bowel-habit satisfaction
Efficacy of daily intake of Lactobacillus casei Shirota on respiratory symptoms and influenza vaccination immune response: a randomized, double-blind, placebo-controlled trial in healthy elderly nursing home residents.
Am J Clin Nutr (2012) · Rct · n=737
PRIMARY ENDPOINTS ALL NULL: no effect on days with respiratory symptoms, probability of respiratory symptoms, or post-vaccination antibody titre
Probiotics and synbiotics in chronic constipation in adults: A systematic review and meta-analysis of randomized controlled trials.
Clin Nutr (2022) · Meta analysis
Probiotics overall increased stool frequency (SMD 0.71, 95% CI 0.37-1.04, p<0.00001) — but the effect was driven by Bifidobacterium lactis, 'not mixtures of probiotics, Bacillus coagulans Unique IS2 or Lactobacillus casei Shirota'
A study into the effect of Lactobacillus casei Shirota in preventing antibiotic associated diarrhoea including Clostridioides difficile infection in patients with spinal cord injuries: a multicentre randomised, double-blind, placebo-controlled trial.
EClinicalMedicine (2021) · Rct · n=359
PRIMARY ENDPOINT NULL: antibiotic-associated diarrhoea at 30 days 45% vs 42.1% (RR 1.071, 95% CI 0.8-1.4, p=0.639)
Both B. infantis 35624 and L. casei Shirota are closely matched — the best choice depends on your specific health goals.
For improve digestion, B. infantis 35624 has a higher relevance score (58 vs 52).
No known interactions between B. infantis 35624 and L. casei Shirota have been documented in our database. However, always consult a healthcare provider before combining supplements.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.