Lactobacillus casei
Research reviewed: Up until 03/2026
Lactobacillus casei (Lacticaseibacillus casei) is a dietary supplement with 7 published peer-reviewed studies involving 1,566 participants, researched for Immune Support, Diarrhea Prevention, Metabolic Health.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Immune Support
StrongDiarrhea Prevention
StrongMetabolic Health
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Immune Support
To evaluate L. casei DN-114 001 on duration of common infections in elderly.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate L. casei DN-114 001 on duration of common infections in elderly.
Dose
10 billion CFU/day in fermented milk
Participants
1072 elderly volunteers (≥70 years)
Duration
3 months
Results
L. casei significantly reduced the duration of common infections by 20% and showed a trend towards reduced incidence, particularly for upper respiratory infections.
How They Measured It
Duration and incidence of respiratory and GI infections
To assess L. casei Shirota on NK cell activity and immune function.
Study Type
Randomised controlled trial
Purpose
To assess L. casei Shirota on NK cell activity and immune function.
Dose
6.5 billion CFU/day in fermented milk
Participants
30 healthy middle-aged adults
Duration
4 weeks
Results
L. casei Shirota significantly increased NK cell activity and shifted cytokine balance towards Th1 response.
How They Measured It
NK cell activity, cytokine profiles
To evaluate L. casei on immune response to influenza vaccination.
Study Type
Double-blind, placebo-controlled
Purpose
To evaluate L. casei on immune response to influenza vaccination.
Dose
10 billion CFU/day
Participants
86 healthy adults over 70 years
Duration
13 weeks
Results
L. casei group had significantly higher antibody responses to influenza vaccine and more sustained titers at 5 months.
How They Measured It
Seroconversion rates, IgG titers
Diarrhea Prevention
To evaluate L. casei in prevention of antibiotic-associated diarrhea in hospitalized patients.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate L. casei in prevention of antibiotic-associated diarrhea in hospitalized patients.
Dose
10 billion CFU twice daily
Participants
135 hospitalized patients
Duration
Duration of antibiotics + 1 week
Results
L. casei significantly reduced antibiotic-associated diarrhea (12% vs 34% placebo) and C. difficile-associated diarrhea (0% vs 17% placebo).
How They Measured It
Incidence of diarrhea, stool frequency and consistency
To assess L. casei for prevention of AAD and C. difficile diarrhea in older hospitalized patients.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess L. casei for prevention of AAD and C. difficile diarrhea in older hospitalized patients.
Dose
6.5 billion CFU twice daily
Participants
135 hospitalized patients ≥50 years
Duration
Antibiotic course + 1 week follow-up
Results
Incidence of AAD was significantly reduced in L. casei group. Zero cases of C. difficile diarrhea in treatment group vs 9% placebo.
How They Measured It
Incidence of AAD, C. difficile toxin assay
Metabolic Health
To evaluate L. casei supplementation on metabolic parameters in type 2 diabetes.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate L. casei supplementation on metabolic parameters in type 2 diabetes.
Dose
8 × 10^9 CFU/day
Participants
64 patients with type 2 diabetes
Duration
8 weeks
Results
L. casei significantly improved fasting glucose and HbA1c levels compared to placebo. hs-CRP and TNF-alpha also decreased significantly.
How They Measured It
Fasting glucose, HbA1c, lipid profile, inflammatory markers
To evaluate L. casei on body composition and metabolic markers in overweight adults.
Study Type
Double-blind RCT
Purpose
To evaluate L. casei on body composition and metabolic markers in overweight adults.
Dose
10 billion CFU/day
Participants
44 overweight adults
Duration
12 weeks
Results
L. casei combined with caloric restriction led to greater reductions in body fat percentage and LDL cholesterol compared to diet alone.
How They Measured It
BMI, body fat percentage, lipid profile, insulin resistance
Frequently Asked Questions
Common questions about Lactobacillus casei research
There are currently 7 peer-reviewed studies on Lactobacillus casei (Lacticaseibacillus casei), involving 1,566 total participants. Research covers Immune support, Diarrhea prevention, Gut health and 1 more areas. The overall evidence strength is rated as Strong.
The evidence is currently rated as "Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (7 human studies), and reported outcomes.
Lactobacillus casei has been researched for: Immune support, Diarrhea prevention, Gut health, Metabolic health. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 7 out of 7 studies are human trials. Human trials carry more weight in our evidence scoring system.
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