Herb & supplement monograph

Limosilactobacillus Reuteri Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated July 2026
What is this page for?

First and foremost: how Limosilactobacillus Reuteri interacts with medications. The heart of this page is the interaction list — every drug Limosilactobacillus Reuteri is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Limosilactobacillus Reuteri is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Interaction report

Drugs that interact with Limosilactobacillus Reuteri

182 medications have a known interaction with Limosilactobacillus Reuteri, graded by severity. Select any drug for the full evidence-based detail.

2,830 drugs
AmikacinAmikin, Arikayce
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Amikacin interaction Amikacin drug page: uses, dosage & side effects
AmoxicillinAmix, Amoram, Amoxident, Amoxil Capsules, Amoxil Injection, Galenamox +3 more
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Amoxicillin interaction Amoxicillin drug page: uses, dosage & side effects
Amoxicillin VeterinaryBiomox
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Amoxicillin Veterinary interaction
Amoxicillin, Clavulanate PotassiumAugmentin, Augmentin '125/31 SF', Augmentin '250/62 SF', Augmentin XR, Augmentin-Duo 400/57, Clavulin
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Amoxicillin, Clavulanate Potassium interaction
Amoxicillin, Omeprazole Magnesium, RifabutinTalicia
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Amoxicillin, Omeprazole Magnesium, Rifabutin interaction
Amphotericin, TetracyclineMysteclin-F
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Amphotericin, Tetracycline interaction
AmpicillinOmnipen, Omnipen-N, Penbritin, Principen, Rimacillin
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Ampicillin interaction Ampicillin drug page: uses, dosage & side effects
Ampicillin, SulbactamUnasyn
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Ampicillin, Sulbactam interaction
Avibactam Sodium, CeftazidimeAvycaz
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Avibactam Sodium, Ceftazidime interaction Avibactam Sodium, Ceftazidime drug page: uses, dosage & side effects
AzithromycinAzasite, Zithromax, Zmax
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Azithromycin interaction Azithromycin drug page: uses, dosage & side effects
AztreonamAzactam
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Aztreonam interaction Aztreonam drug page: uses, dosage & side effects
BacampicillinPenglobe
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Bacampicillin interaction
BacitracinBaci-IM, Baciguent, Bacitracin Ointment
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Bacitracin interaction Bacitracin drug page: uses, dosage & side effects
BenznidazoleBenznidazole
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Benznidazole interaction Benznidazole drug page: uses, dosage & side effects
Bismuth Subsalicylate, Metronidazole, TetracyclineHelidac
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Bismuth Subsalicylate, Metronidazole, Tetracycline interaction Bismuth Subsalicylate, Metronidazole, Tetracycline drug page: uses, dosage & side effects
CapreomycinCapastat
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Capreomycin interaction
Carbenicillin Indanyl SodiumGeocillin
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Carbenicillin Indanyl Sodium interaction
CefaclorCeclor, Ceclor CD
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefaclor interaction Cefaclor drug page: uses, dosage & side effects
CefadroxilCef-Tab, Duricef, Ultracef
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefadroxil interaction Cefadroxil drug page: uses, dosage & side effects
CefamandoleMandol
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefamandole interaction
CefazolinAncef
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefazolin interaction Cefazolin drug page: uses, dosage & side effects
CefdinirOmnicef
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefdinir interaction Cefdinir drug page: uses, dosage & side effects
Cefditoren PivoxilSpectracef
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefditoren Pivoxil interaction
CefepimeMaxipime
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefepime interaction Cefepime drug page: uses, dosage & side effects
Cefiderocol Sulfate TosylateFetroja
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefiderocol Sulfate Tosylate interaction Cefiderocol Sulfate Tosylate drug page: uses, dosage & side effects
CefiximeSuprax
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefixime interaction Cefixime drug page: uses, dosage & side effects
CefmetazoleZefazone
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefmetazole interaction
CefonicidMonocid
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefonicid interaction
CefoperazoneCefobid
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefoperazone interaction
CefotaximeClaforan
Moderate Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L.

Read the full Limosilactobacillus Reuteri + Cefotaxime interaction Cefotaxime drug page: uses, dosage & side effects
Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each drug listed above links to the full report for that exact Limosilactobacillus Reuteri combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
The big picture

The kinds of drugs Limosilactobacillus Reuteri affects

Every type of medication (drug category) Limosilactobacillus Reuteri is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 1 drug category Limosilactobacillus Reuteri interacts with
Antibiotic Drugs
Antibiotic Drugs

Theoretically, taking Limosilactobacillus reuteri with antibiotic drugs might decrease the effectiveness of L. reuteri.
L. reuteri preparations usually contain live and active organisms. Therefore, simultaneously taking antibiotics might kill a significant number of the organisms. Tell patients to separate administration of antibiotics and L. reuteri preparations by at least two hours.

Likelihood Probable Evidence D
Monograph

Limosilactobacillus Reuteri: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Limosilactobacillus reuteri (formerly Lactobacillus reuteri) is a probiotic bacterium found in the human gut and certain fermented foods. It has the most supportive evidence for reducing crying in breastfed infants with colic and for some types of diarrhea, while many other uses remain unproven. It is generally well tolerated in healthy people, but people who are very ill or immunocompromised should talk to a doctor first.

Scientific name
Limosilactobacillus reuteri
Family
Lactobacillaceae
Part used
Live bacterial cells (probiotic strains)
Common forms
Chewable tablets, drops/oils, capsules, powders, fortified foods and yogurt
People commonly use it for
  • Infant colic
  • Diarrhea (including antibiotic-associated)
  • Digestive health
  • Oral and gum health
  • Constipation
  • Immune support

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallUse caution

Generally well tolerated in healthy people, but caution is needed in those who are seriously ill or immunocompromised.

PregnancyPossibly Safe

When used orally and appropriately.

Read the full pregnancy detail
BreastfeedingPossibly Safe

When used orally and appropriately. Although clinical research during lactation is lacking, no safety concerns have been shown in clinical research in...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Limosilactobacillus reuteri is a type of friendly bacteria, also called a probiotic. It was renamed in 2020; you may still see it on labels as Lactobacillus reuteri. It naturally lives in the gut, mouth, and other areas of humans and many animals, and it is also found in some fermented foods and breast milk.

Different strains of this bacterium are sold as supplements. They come in many forms, including drops, chewable tablets, capsules, and powders. People take it most often for digestive and infant health, and some products are designed to dissolve in the mouth to support gum and oral health.

How it works

Like other probiotics, L. reuteri is thought to work by helping to balance the community of microbes living in the gut and mouth. It may crowd out harmful bacteria and support a healthier microbial environment.

Some strains produce a substance called reuterin, which can slow the growth of certain harmful bacteria, yeasts, and other microbes in laboratory tests. The bacteria may also interact with the immune system and the lining of the gut. Much of this work comes from laboratory and animal research, so the exact effects in people are still being studied.

Effectiveness

Does Limosilactobacillus Reuteri work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 43 uses evaluated
5 Possibly effective 38 Insufficient evidence
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.
Possibly Effective Abdominal pain
Rating & evidence shown verbatim from Natural Medicines

Oral Limosilactobacillus reuteri seems to reduce abdominal pain in children 4 years and older. It is unclear if any species are beneficial in adults.

Possibly Effective Colic
Rating & evidence shown verbatim from Natural Medicines

Oral Limosilactobacillus reuteri seems to be beneficial for colic.

Possibly Effective Constipation
Rating & evidence shown verbatim from Natural Medicines

Oral Limosilactobacillus reuteri seems to be beneficial for functional constipation.

Possibly Effective Helicobacter pylori
Rating & evidence shown verbatim from Natural Medicines

Oral Limosilactobacillus reuteri seems to reduce the adverse effects associated with H. pylori symptoms and standard treatment regimens. It is unclear if oral L. reuteri improves the rate of H. pylori eradication.

Possibly Effective Hypercholesterolemia
Rating & evidence shown verbatim from Natural Medicines

Oral Limosilactobacillus reuteri seems to be modestly beneficial for lowering cholesterol levels.

Also studied for 38 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Antibiotic-associated diarrhea
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for antibiotic-associated diarrhea (AAD) in adults and children.

Insufficient Reliable Evidence To Rate Atopic dermatitis (eczema)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral L. reuteri is beneficial for the treatment or prevention of atopic dermatitis.

Insufficient Reliable Evidence To Rate Atopic disease
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for the prevention of atopic disease in infants.

Insufficient Reliable Evidence To Rate Bacterial vaginosis
Rating & evidence shown verbatim from Natural Medicines

Oral Limosilactobacillus reuteri has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Cancer
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral Limosilactobacillus reuteri for cancer prevention or treatment, there is insufficient reliable information about the clinical effects of L. reuteri for this condition.

Insufficient Reliable Evidence To Rate Canker sores
Rating & evidence shown verbatim from Natural Medicines

It is unclear if Limosilactobacillus reuteri lozenges are beneficial for canker sores.

Insufficient Reliable Evidence To Rate Clostridioides difficile infection
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for C. difficile prevention.

Insufficient Reliable Evidence To Rate Cystic fibrosis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for cystic fibrosis.

Insufficient Reliable Evidence To Rate Dental caries
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for dental caries prevention.

Insufficient Reliable Evidence To Rate Dental peri-implantitis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for dental peri-implantitis.

Insufficient Reliable Evidence To Rate Dental plaque
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for dental plaque prevention.

Insufficient Reliable Evidence To Rate Diabetes
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for type 2 diabetes.

Insufficient Reliable Evidence To Rate Diverticulitis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for diverticulitis.

Insufficient Reliable Evidence To Rate Gingivitis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for gingivitis.

Insufficient Reliable Evidence To Rate Group B streptococcal colonization
Rating & evidence shown verbatim from Natural Medicines

Oral Limosilactobacillus reuteri has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate HIV/AIDS
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral Limosilactobacillus reuteri for HIV/AIDS, there is insufficient reliable information about the clinical effects of L. reuteri for this condition.

Insufficient Reliable Evidence To Rate Hypertension
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral Limosilactobacillus reuteri for hypertension, there is insufficient reliable information about the clinical effects of L. reuteri for this condition.

Insufficient Reliable Evidence To Rate Irritable bowel syndrome (IBS)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for IBS.

Insufficient Reliable Evidence To Rate Lactose intolerance
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral L. reuteri is beneficial for lactose intolerance.

Insufficient Reliable Evidence To Rate Low birth weight
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for improving outcomes in very low birth weight (VLBW) infants.

Insufficient Reliable Evidence To Rate Lyme disease
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral Limosilactobacillus reuteri for Lyme disease, there is insufficient reliable information about the clinical effects of L. reuteri for this condition.

Insufficient Reliable Evidence To Rate Metabolic syndrome
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for metabolic syndrome.

Insufficient Reliable Evidence To Rate Necrotizing enterocolitis (NEC)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial or safe for NEC prevention.

Insufficient Reliable Evidence To Rate Nonalcoholic fatty liver disease (NAFLD)
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral Limosilactobacillus reuteri for NAFLD, there is insufficient reliable information about the clinical effects of L. reuteri for this condition.

Insufficient Reliable Evidence To Rate Obesity
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral Limosilactobacillus reuteri for obesity, there is insufficient reliable information about the clinical effects of L. reuteri for this condition.

Insufficient Reliable Evidence To Rate Oropharyngeal candidiasis
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral Limosilactobacillus reuteri for oropharyngeal candidiasis, there is insufficient reliable information about the clinical effects of L. reuteri for this condition.

Insufficient Reliable Evidence To Rate Osteopenia
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for osteopenia.

Insufficient Reliable Evidence To Rate Peri-implant mucositis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for peri-implant mucositis.

Insufficient Reliable Evidence To Rate Periodontitis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for periodontitis.

Insufficient Reliable Evidence To Rate Polycystic ovary syndrome (PCOS)
Rating & evidence shown verbatim from Natural Medicines

Oral Limosilactobacillus reuteri has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Prader-Willi syndrome (PWS)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for PWS.

Insufficient Reliable Evidence To Rate Psoriasis
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral Limosilactobacillus reuteri for psoriasis, there is insufficient reliable information about the clinical effects of L. reuteri for this condition.

Insufficient Reliable Evidence To Rate Respiratory tract infections
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for preventing respiratory tract infections.

Insufficient Reliable Evidence To Rate Rheumatoid arthritis (RA)
Rating & evidence shown verbatim from Natural Medicines

Oral Limosilactobacillus reuteri has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Rotaviral diarrhea
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral Limosilactobacillus reuteri is beneficial for rotaviral diarrhea.

Insufficient Reliable Evidence To Rate Short bowel syndrome
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral Limosilactobacillus reuteri for short bowel syndrome, there is insufficient reliable information about the clinical effects of L. reuteri for this condition.

Insufficient Reliable Evidence To Rate Ulcerative colitis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if giving Limosilactobacillus reuteri by enema is beneficial for ulcerative colitis.

Insufficient Reliable Evidence To Rate Urinary tract infections (UTIs)
Rating & evidence shown verbatim from Natural Medicines

Oral Limosilactobacillus reuteri has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

For most healthy children and adults, L. reuteri is generally considered well tolerated when used as directed. However, probiotics are live organisms, so they are not risk-free for everyone.

People who are seriously ill, have weakened immune systems, have central venous catheters, or have had recent major surgery should not take probiotics without medical advice, because there have been rare reports of serious infections in vulnerable patients. Premature or critically ill infants should only use probiotics under a doctor's supervision.

Because there is limited safety information, pregnant and breastfeeding people should use caution and talk with their doctor or pharmacist before starting it. Always choose products from reputable brands, since supplements are not tightly regulated.

Side effects

Side effects are usually mild. The most common ones are gas, bloating, and mild stomach upset, especially when first starting. These often improve over a few days.

Serious side effects are rare. The main concern is a small risk of infection in people who are very ill or immunocompromised. If you develop a fever, severe stomach pain, or other worrying symptoms, stop the product and seek medical care.

Limosilactobacillus Reuteri: Reported Adverse Effects

Documented safety reports on Limosilactobacillus Reuteri from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Reports by condition
Constipation Gastrointestinal

Orally, taking Limosilactobacillus reuteri alone or in combination with other probiotics may cause gastrointestinal side effects including diarrhea and constipation; however, these events are uncommon.

  1. Beerepoot MA, ter Riet G, Nys S, van der Wal WM, de Borgie CA, de Reijke TM,Prins JM, Koeijers J, Verbon A, Stobberingh E, Geerlings SE. Lactobacilli vs antibiotics to prevent urinary tract infections: a randomized, double-blind, noninferiority trial in p
  2. Ojetti V, Gigante G, Gabrielli M, et al. The effect of oral supplementation with Lactobacillus reuteri or tilactase in lactose intolerant patients: randomized trial. Eur Rev Med Pharmacol Sci. 2010;14(3):163-70.
Sepsis Immunologic

Since Limosilactobacillus reuteri preparations contain live and active microorganisms, there is some concern that they might cause pathogenic infection in some patients. Some lactobacilli species have been isolated in some cases of bacteremia, sepsis, splenic abscess, endocarditis, necrotizing fasciitis, pancreatic necrosis, and meningoencephalitis. Most of these cases are thought to be due to the translocation of bacteria from other locations in the body in which they occur naturally, such as the oral cavity and gastrointestinal tract, and not to dietary or supplemental intake. However, there is one case of sepsis causing death of a very preterm neonate following the use of an L. reuteri supplement.

  1. Rossi F, Amadoro C, Gasperi M, Colavita G. Lactobacilli infection case reports in the last three years and safety implications. Nutrients. 2022;14(6):1178.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no single official dose for L. reuteri. Probiotic doses are usually measured in colony-forming units (CFU), and the right amount can depend on the specific strain, the product, and the reason for use.

Because doses and strains vary so much, the best approach is to follow the directions on the product label and check with your pharmacist or doctor — especially before giving it to an infant. Do not assume a higher dose is better.

Pregnancy & Breastfeeding

Limosilactobacillus Reuteri & Breastfeeding

Possibly Safe

When used orally and appropriately. Although clinical research during lactation is lacking, no safety concerns have been shown in clinical research involving infants up to 3 months of age.

  1. Savino F, Cordisco L, Tarasco V, et al. Lactobacillus reuteri DSM 17938 in infantile colic: a randomized, double-blind, placebo-controlled trial. Pediatrics 2010;126:e526-33.
  2. Savino F, Pelle E, Palumeri E, et al. Lactobacillus reuteri (American Type Culture Collection Strain 55730) versus simethicone in the treatment of infantile colic: a prospective randomized study. Pediatrics 2007;119:e124-30.
  3. Chau K, Lau E, Greenberg S, Jacobson S, Yazdani-Brojeni P, Verma N, Koren G.Probiotics for infantile colic: a randomized, double-blind, placebo-controlled trial investigating Lactobacillus reuteri DSM 17938. J Pediatr 2015;166(1):74-8.
  4. Indrio F, Di Mauro A, Riezzo G, Civardi E, Intini C, Corvaglia L, Ballardini E, Bisceglia M, Cinquetti M, Brazzoduro E, Del Vecchio A, Tafuri S, Francavilla R. Prophylactic use of a probiotic in the prevention of colic, regurgitation, and functional const
  5. Oncel MY, Sari FN, Arayici S, Guzoglu N, Erdeve O, Uras N, Oguz SS, Dilmen U. Lactobacillus Reuteri for the prevention of necrotising enterocolitis in very low birthweight infants: a randomised controlled trial. Arch Dis Child Fetal Neonatal Ed. 2014;99(2
  6. Sung V, Hiscock H, Tang ML, Mensah FK, Nation ML, Satzke C, Heine RG, Stock A,Barr RG, Wake M. Treating infant colic with the probiotic Lactobacillus reuteri: double blind, placebo controlled randomised trial. BMJ. 2014 1;348:g2107.
  7. Szajewska H, Gyrczuk E, Horvath A. Lactobacillus reuteri DSM 17938 for the management of infantile colic in breastfed infants: a randomized, double-blind,placebo-controlled trial. J Pediatr. 2013;162(2):257-62.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 14 references that drive our Limosilactobacillus Reuteri monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  2. Savino F, Cordisco L, Tarasco V, et al. Lactobacillus reuteri DSM 17938 in infantile colic: a randomized, double-blind, placebo-controlled trial. Pediatrics 2010;126:e526-33.
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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Pharmacist Counseling Corner

Limosilactobacillus Reuteri: Common Questions

What is Limosilactobacillus Reuteri used for, and does it work?
People use Limosilactobacillus Reuteri for many reasons, but the evidence varies by use. According to the Natural Medicines database, there is at least some clinical evidence supporting Limosilactobacillus Reuteri for Abdominal pain, Colic, Constipation and Helicobacter pylori. For most other uses it has been studied for, the evidence is currently insufficient to rate. See the graded list on this page, and always confirm with your pharmacist or doctor.
Does Limosilactobacillus Reuteri interact with prescription medications?
Yes. We list 182 medications with a known interaction with Limosilactobacillus Reuteri. Use the checker above to see how Limosilactobacillus Reuteri interacts with a specific drug.
How are Limosilactobacillus Reuteri interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Limosilactobacillus Reuteri with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Limosilactobacillus Reuteri interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
What is Limosilactobacillus Reuteri used for?
It is a probiotic most often used for infant colic and certain types of diarrhea. People also take it for general digestive and oral health, though the evidence for those uses is weaker.
Is it the same as Lactobacillus reuteri?
Yes. The bacterium was reclassified and renamed in 2020. Older products and studies may still call it Lactobacillus reuteri.
Is Limosilactobacillus Reuteri safe for babies?
Certain strains have been studied in breastfed infants with colic and are generally well tolerated, but you should always talk to your pediatrician before giving any probiotic to a baby, especially if the infant was premature or is ill.
Can I take it during pregnancy or while breastfeeding?
There is not enough safety data, so it is best to use caution and check with your doctor or pharmacist before using it during pregnancy or breastfeeding.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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