Lactobacillus reuteri

Unique probiotic bacteria that produces reuterin antimicrobial compound and supports digestive health, immune function, and may benefit bone health and cardiovascular function

Scientific nameLactobacillus reuteri FormulaLive bacterial culture Molecular weightN/A - Living organism g/mol CASN/A - Probiotic strain

80 absorption score

10 safety / 10

35 USD per month

6 documented interactions

Check it against something

Evidence level B

Lactobacillus reuteri with:

78 out of 100

Works better together Compatible. Timing differs, so follow each supplement's own window.

Check it against your whole stack →

What it does

mechanism and evidence for each claim

Enhanced digestive health and antimicrobial protection

Produces reuterin compound that protects against harmful bacteria

Produces antimicrobial reuterin and strengthens gut barrier Evidence A-grade 2-6 weeks of consistent supplementation

Improved bone health and density

May increase bone mineral density and reduce bone loss

Modulates bone metabolism and reduces inflammation Evidence B-grade 3-6 months of regular use

Enhanced cardiovascular function

May improve cholesterol levels and reduce cardiovascular risk factors

Produces compounds that benefit heart health and circulation Evidence B-grade 6-12 weeks of consistent use

Strengthened immune system function

Enhances immune response and reduces infection susceptibility

Stimulates immune cell activity and antibody production Evidence A-grade 4-8 weeks of regular supplementation

Reduced colic and digestive discomfort in infants

Clinically proven to reduce infant colic and crying time

Balances infant gut microbiome and reduces inflammation Evidence A-grade 1-3 weeks of consistent use

Others take these for the same thing

Same goal, different mechanism — check any of them against this one

Probiotics for Autoimmune Disease Support Gut health & immune modulation 10-100 billion CFU daily B 60% Calcium Bone health & muscle function 1,000-1,200 mg A 30% Turmeric Anti-inflammatory & antioxidant 300-1000mg A 3% Magnesium Glycinate Superior absorption sleep & muscle support 200-600 mg A 90% Vitamin D3 Bone health & immune support 1000-2000 IU A 85% Magnesium Citrate Balanced absorption & digestive support 300-600 mg A 35%

Every pair we checked

12 combinations scored by the engine

Lactobacillus reuteri + Caffeine No documented interaction either way No known interaction 70

Lactobacillus reuteri + Creatine Monohydrate No documented interaction either way No known interaction 70

Lactobacillus reuteri + Whey Protein No documented interaction either way No known interaction 70

Lactobacillus reuteri + Bovine Collagen No documented interaction either way No known interaction 70

Lactobacillus reuteri + DHA No documented interaction either way No known interaction 70

Lactobacillus reuteri + Turmeric No documented interaction either way No known interaction 70

Lactobacillus reuteri + Fish Oil (EPA/DHA) No documented interaction either way No known interaction 70

Lactobacillus reuteri + Vitamin D3 Enhanced bone health and immune function benefits Works better together 78

Lactobacillus reuteri + Calcium Carbonate Synergistic bone health and cardiovascular benefits Works better together 78

Lactobacillus reuteri + Lactase Improved gut health and potentially reduced lactose intolerance Works better together 78

Lactobacillus reuteri + Magnesium Oxide Synergistic bone health and cardiovascular benefits Works better together 78

Lactobacillus reuteri + Omega-3 + Curcumin + Vitamin D Triple Anti-Inflammatory Formula Enhanced bone health and immune function benefits Works better together 83

Dosage

With meals daily

Daily1-10 billion CFU

Infant colic100 million CFU daily for infants

Bone health1-10 billion CFU daily long-term

Digestive support1-10 billion CFU daily with meals

Cardiovascular support1-10 billion CFU daily with meals

When to expect it

First Effects1-2 weeks for digestive improvements and immune changes

Peak Benefits4-12 weeks for maximum digestive and immune benefits, 3-6 months for bone health

Deficiency DevelopmentBeneficial bacteria depleted by antibiotics, processed foods, stress

Toxicity OnsetNo known toxicity - extremely safe probiotic

How to measure it

$300-600

MarkerBone density scans, cardiovascular markers, stool microbiome analysis

OptimalAdequate bone density, healthy cardiovascular markers

Deficient belowLow bone density, elevated cardiovascular risk markers

FrequencyMonitor for bone health and cardiovascular optimization

What people actually reported to the FDA

CAERS, 1 reports naming it as the suspect

Most reported effects

Constipation 1

Named as the suspect 1 reports of 3 that mention it at all

Serious outcome 100% hospitalisation, emergency room or worse

Hospitalization1

Reports are voluntary and unverified — they record what someone experienced while taking something, not what the compound caused. Counts skew towards products people take a lot of, and a serious outcome is more likely to be reported than a mild one, so these are not rates. How we filter them →

Works better with

3 documented

Vitamin D

Enhanced bone health and immune function benefits

Both support bone metabolism and immune system · level B

Calcium Magnesium

Synergistic bone health and cardiovascular benefits

L. reuteri enhances mineral absorption and utilization · level B

Omega 3 Fatty Acids

Enhanced cardiovascular and anti-inflammatory benefits

Both support heart health through different pathways · level C

What not to take with Lactobacillus reuteri

3 documented

Broad Spectrum Antibiotics

Antibiotics eliminate L. reuteri and disrupt gut microbiome

Antimicrobial action kills beneficial bacteria · high significance

High Sugar Diet

Excessive sugar may impair probiotic effectiveness

Sugar promotes harmful bacteria growth competing with probiotics · moderate significance

Chronic Stress

Long-term stress may reduce probiotic colonization and benefits

Stress hormones affect gut microbiome composition · moderate significance

Medication interactions

Discuss these with a pharmacist before combining

antibiotics Moderate

Antibiotics significantly reduce L. reuteri viability

What to do: Take probiotics 2-3 hours after antibiotic doses

immunosuppressive-medications Minor

Theoretical infection risk in severely immunosuppressed patients

What to do: Use caution in severe immunosuppression

Available forms

bioavailability compared

Lactobacillus reuteri DSM 17938 (Clinical strain) 80

Lactobacillus reuteri DSM 17938 (Clinical strain): Reuterin production, Bone health benefits, Infant colic research, Cardiovascular support

Food sources

before you supplement

Human breast milk Natural source, variable CFU · 95

Fermented dairy products (some varieties) 10^4-10^6 CFU per serving · 70

Fermented vegetables (limited) Variable, typically low levels · 60

L. reuteri probiotic supplements 100 million to 10 billion CFU per serving · 80

Too little

deficiency signs

Gut microbiome imbalance symptoms:
Increased susceptibility to gastrointestinal infections
Poor bone health and increased fracture risk
Elevated cardiovascular risk factors
Compromised immune function and frequent infections
Infant colic and digestive discomfort
Reduced production of beneficial metabolites

Too much

toxicity signs

Extremely safe with minimal adverse effects:
Temporary digestive adjustment during initial supplementation
Very rare bacterial overgrowth in severely immunocompromised
No documented serious adverse effects in healthy individuals
Safe for daily long-term use including infants

Who benefits most

infant-colic-digestive-issues

Clinically proven to reduce infant colic and crying time

100 million CFU daily for infants

bone-health-seekers

May improve bone mineral density and reduce bone loss

1-10 billion CFU daily long-term

digestive-health-maintenance

Provides antimicrobial protection and supports gut health

1-10 billion CFU daily with meals

cardiovascular-health-support

May improve cholesterol levels and support heart health

1-10 billion CFU daily with meals

immune-system-support

Enhances immune function and reduces infection risk

1-10 billion CFU daily

Where to buy it

compare forms first

Look for Lactobacillus reuteri at 1-10 billion CFU per serving. The form that matters here is Lactobacillus reuteri DSM 17938 (Clinical strain).

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What else affects it

Beyond other supplements

High sugar diet

Excessive sugar may impair probiotic effectiveness

Sugar promotes harmful bacteria growth competing with probiotics

Chronic stress

Long-term stress may reduce probiotic colonization and benefits

Stress hormones affect gut microbiome composition

How it works

Produces antimicrobial reuterin providing broad-spectrum protection
Modulates bone metabolism and reduces bone resorption
Produces compounds that benefit cardiovascular health
Strengthens gut barrier function and reduces inflammation
Stimulates immune cell activity and antibody production
Balances infant gut microbiome reducing colic symptoms

Key findings

what the evidence supports

Clinically proven effective for reducing infant colic symptoms
Strong evidence for bone health benefits and mineral density
Proven cardiovascular benefits and cholesterol improvement
Unique antimicrobial properties through reuterin production

Sources: NIH Examine.com · data reviewed 2026-08-02

Compiled by Denis, who maintains this database and holds no medical qualification — every figure here is sourced or derived, never asserted. How we calculate it →

Common questions

What are the benefits of Lactobacillus reuteri?

Documented effects: Enhanced digestive health and antimicrobial protection; Improved bone health and density; Enhanced cardiovascular function; Strengthened immune system function. Produces reuterin compound that protects against harmful bacteria

How much Lactobacillus reuteri should you take per day?

The common daily range is 1-10 billion CFU. By goal — infant colic: 100 million CFU daily for infants; bone health: 1-10 billion CFU daily long-term; digestive support: 1-10 billion CFU daily with meals; cardiovascular support: 1-10 billion CFU daily with meals.

When is the best time to take Lactobacillus reuteri?

With meals daily. First effects are typically reported within 1-2 weeks for digestive improvements and immune changes.

What are the side effects of Lactobacillus reuteri?

At excessive doses: Extremely safe with minimal adverse effects:, Temporary digestive adjustment during initial supplementation, Very rare bacterial overgrowth in severely immunocompromised, No documented serious adverse effects in healthy individuals, Safe for daily long-term use including infants. Safety rating at normal doses is 10 out of 10.

What should you not take with Lactobacillus reuteri?

Separate it from Broad Spectrum Antibiotics, High Sugar Diet, Chronic Stress by two to four hours. Antibiotics eliminate L. reuteri and disrupt gut microbiome

Does Lactobacillus reuteri interact with medications?

Documented interactions with antibiotics, immunosuppressive-medications. Discuss these with a pharmacist before combining.

How do you know if you need Lactobacillus reuteri?

The marker is Bone density scans, cardiovascular markers, stool microbiome analysis, optimal range Adequate bone density, healthy cardiovascular markers. Common deficiency signs: Gut microbiome imbalance symptoms:, Increased susceptibility to gastrointestinal infections, Poor bone health and increased fracture risk, Elevated cardiovascular risk factors.

Taken for

38 Joints & Bones

Vitamin D3 · Calcium Carbonate · Bovine Collagen

74 Digestion

Lactase · Lactobacillus acidophilus · Protease