Herb & supplement monograph

Bifidobacterium Animalis Subsp. Lactis Drug Interactions, Uses, Effectiveness, Safety & More

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

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

But these pages have grown well beyond that into a full monograph — what Bifidobacterium Animalis Subsp. Lactis 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 Bifidobacterium Animalis Subsp. Lactis

182 medications have a known interaction with Bifidobacterium Animalis Subsp. Lactis, graded by severity. Select any drug for the full evidence-based detail.

2,830 drugs
AmikacinAmikin, Arikayce
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Amikacin interaction Amikacin drug page: uses, dosage & side effects
AmoxicillinAmix, Amoram, Amoxident, Amoxil Capsules, Amoxil Injection, Galenamox +3 more
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Amoxicillin interaction Amoxicillin drug page: uses, dosage & side effects
Amoxicillin VeterinaryBiomox
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + 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 Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Amoxicillin, Clavulanate Potassium interaction
Amoxicillin, Omeprazole Magnesium, RifabutinTalicia
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Amoxicillin, Omeprazole Magnesium, Rifabutin interaction
Amphotericin, TetracyclineMysteclin-F
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Amphotericin, Tetracycline interaction
AmpicillinOmnipen, Omnipen-N, Penbritin, Principen, Rimacillin
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Ampicillin interaction Ampicillin drug page: uses, dosage & side effects
Ampicillin, SulbactamUnasyn
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Ampicillin, Sulbactam interaction
Avibactam Sodium, CeftazidimeAvycaz
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Avibactam Sodium, Ceftazidime interaction Avibactam Sodium, Ceftazidime drug page: uses, dosage & side effects
AzithromycinAzasite, Zithromax, Zmax
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Azithromycin interaction Azithromycin drug page: uses, dosage & side effects
AztreonamAzactam
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Aztreonam interaction Aztreonam drug page: uses, dosage & side effects
BacampicillinPenglobe
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Bacampicillin interaction
BacitracinBaci-IM, Baciguent, Bacitracin Ointment
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Bacitracin interaction Bacitracin drug page: uses, dosage & side effects
BenznidazoleBenznidazole
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Benznidazole interaction Benznidazole drug page: uses, dosage & side effects
Bismuth Subsalicylate, Metronidazole, TetracyclineHelidac
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Bismuth Subsalicylate, Metronidazole, Tetracycline interaction Bismuth Subsalicylate, Metronidazole, Tetracycline drug page: uses, dosage & side effects
CapreomycinCapastat
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Capreomycin interaction
Carbenicillin Indanyl SodiumGeocillin
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Carbenicillin Indanyl Sodium interaction
CefaclorCeclor, Ceclor CD
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefaclor interaction Cefaclor drug page: uses, dosage & side effects
CefadroxilCef-Tab, Duricef, Ultracef
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefadroxil interaction Cefadroxil drug page: uses, dosage & side effects
CefamandoleMandol
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefamandole interaction
CefazolinAncef
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefazolin interaction Cefazolin drug page: uses, dosage & side effects
CefdinirOmnicef
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefdinir interaction Cefdinir drug page: uses, dosage & side effects
Cefditoren PivoxilSpectracef
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefditoren Pivoxil interaction
CefepimeMaxipime
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefepime interaction Cefepime drug page: uses, dosage & side effects
Cefiderocol Sulfate TosylateFetroja
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefiderocol Sulfate Tosylate interaction Cefiderocol Sulfate Tosylate drug page: uses, dosage & side effects
CefiximeSuprax
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefixime interaction Cefixime drug page: uses, dosage & side effects
CefmetazoleZefazone
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefmetazole interaction
CefonicidMonocid
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefonicid interaction
CefoperazoneCefobid
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + Cefoperazone interaction
CefotaximeClaforan
Moderate Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B.

Read the full Bifidobacterium Animalis Subsp. Lactis + 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 Bifidobacterium Animalis Subsp. Lactis 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 Bifidobacterium Animalis Subsp. Lactis affects

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

All 1 drug category Bifidobacterium Animalis Subsp. Lactis interacts with
Antibiotic Drugs
Antibiotic Drugs

Theoretically, taking Bifidobacterium lactis with antibiotic drugs might decrease the effectiveness of B. lactis.
Since B. lactis preparations usually contain live and active organisms, simultaneously taking antibiotics might kill a significant number of the organisms. Tell patients to separate administration of antibiotics and B. lactis preparations by at least 2 hours.

Likelihood Probable Evidence D
Monograph

Bifidobacterium Animalis Subsp. Lactis: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Bifidobacterium animalis subsp. lactis is a well-studied probiotic bacterium commonly added to supplements and yogurts to support digestion and gut health. It appears generally safe for most healthy people, with the best evidence for improving bowel regularity, but benefits vary by person and strain. Talk with your pharmacist or doctor before starting it, especially if you have a weakened immune system or a serious illness.

Scientific name
Bifidobacterium animalis subsp. lactis
Family
Bifidobacteriaceae
Part used
Live bacterial cells (probiotic strain)
Common forms
Capsules, tablets, powders, sachets, fermented dairy products like yogurt, and combination probiotic supplements
People commonly use it for
  • Digestive health and regularity
  • Constipation relief
  • Immune support
  • Antibiotic-associated diarrhea
  • General gut microbiome balance

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

Safety at a glance
OverallLikely safe

Generally well tolerated by most healthy people when taken as directed.

PregnancyInsufficient reliable information

Insufficient reliable information available. A meta-analysis of four clinical trials shows that taking probiotics during pregnancy increases the relat...

Read the full pregnancy detail
BreastfeedingInsufficient reliable information

Insufficient reliable information available. A meta-analysis of four clinical trials shows that taking probiotics during pregnancy increases the relat...

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

Bifidobacterium animalis subsp. lactis (often shortened to B. lactis) is a type of friendly bacteria, also called a probiotic. It naturally belongs to a group of microbes that live in the intestines of humans and animals.

This bacterium is widely added to dietary supplements, yogurts, and other fermented dairy foods. You may see specific branded strains on product labels, such as those identified by letter-and-number codes. Each strain may behave a little differently in the body.

People take B. lactis mainly to support healthy digestion, encourage regular bowel movements, and help maintain a balanced mix of bacteria in the gut.

How it works

Probiotics like B. lactis are thought to work by adding helpful bacteria to the gut. This may help crowd out less desirable microbes and support a healthier balance in the digestive system.

Proposed mechanisms, many based on laboratory and animal research, include producing short-chain fatty acids that feed the cells lining the gut, supporting the gut barrier, and interacting with the immune system. These actions may help with digestion and how the body responds to certain microbes.

Because much of this work is preliminary or done outside the human body, the exact way it helps in people is still being studied.

Effectiveness

Does Bifidobacterium Animalis Subsp. Lactis work?

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

Evidence overview · 42 uses evaluated
4 Possibly effective 1 Leans ineffective 37 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 Colic
Rating & evidence shown verbatim from Natural Medicines

Oral Bifidobacterium lactis seems to be beneficial for colic.

Possibly Effective Constipation
Rating & evidence shown verbatim from Natural Medicines

Oral Bifidobacterium lactis seems to be beneficial for constipation.

Possibly Effective Irritable bowel syndrome (IBS)
Rating & evidence shown verbatim from Natural Medicines

Oral Bifidobacterium lactis seems to be beneficial for reducing symptoms of IBS when used alone. Its benefits when used in combination with other probiotics are unclear.

Possibly Effective Respiratory tract infections
Rating & evidence shown verbatim from Natural Medicines

Most clinical research shows that taking Bifidobacterium lactis alone or in combination with other probiotics may reduce the risk of respiratory infections in otherwise healthy individuals. In patients who are not otherwise healthy, most clinical research shows that taking oral B. lactis has not demonstrated benefit.

Possibly Ineffective Dental caries
Rating & evidence shown verbatim from Natural Medicines

Oral Bifidobacterium lactis does not seem to be beneficial for preventing dental caries in young children.

Also studied for 37 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Allergic rhinitis (hay fever)
Rating & evidence shown verbatim from Natural Medicines

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

Insufficient Reliable Evidence To Rate Antibiotic-associated diarrhea
Rating & evidence shown verbatim from Natural Medicines

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

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

It is unclear if oral Bifidobacterium lactis is beneficial for the prevention or treatment of atopic dermatitis.

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

Oral Bifidobacterium lactis 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 Bifidobacterium lactis for cancer prevention or treatment, there is insufficient reliable information about the clinical effects of B. lactis for this condition.

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

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

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

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

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

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

Insufficient Reliable Evidence To Rate Critical illness (trauma)
Rating & evidence shown verbatim from Natural Medicines

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

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

It is unclear if Bifidobacterium lactis is beneficial for preventing dental plaque.

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

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

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

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

Insufficient Reliable Evidence To Rate Generalized anxiety disorder (GAD)
Rating & evidence shown verbatim from Natural Medicines

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

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

It is unclear if oral Bifidobacterium lactis is beneficial for gingivitis.

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

It is unclear if oral Bifidobacterium lactis is beneficial for H. pylori; some research suggests that B. lactis may minimize the adverse effects of H. pylori eradication therapy, but not all research agrees.

Insufficient Reliable Evidence To Rate Inflammatory bowel disease (IBD)
Rating & evidence shown verbatim from Natural Medicines

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

Insufficient Reliable Evidence To Rate Malnourishment-related diarrhea
Rating & evidence shown verbatim from Natural Medicines

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

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

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

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

It is unclear if oral Bifidobacterium lactis 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 Bifidobacterium lactis is beneficial or safe for NEC prevention.

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

It is unclear if oral Bifidobacterium lactis is beneficial for neonatal jaundice.

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

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

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

It is unclear if oral Bifidobacterium lactis is beneficial for weight loss.

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

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

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

It is unclear if oral Bifidobacterium lactis is beneficial for preventing otitis media.

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

It is unclear if oral Bifidobacterium lactis is beneficial for periodontitis.

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

Oral Bifidobacterium lactis 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 Bifidobacterium lactis is beneficial for PWS.

Insufficient Reliable Evidence To Rate Pregnancy-induced nausea and vomiting
Rating & evidence shown verbatim from Natural Medicines

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

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

It is unclear if oral Bifidobacterium lactis is beneficial for preventing infections in premature infants.

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

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

Insufficient Reliable Evidence To Rate Radiation-induced diarrhea
Rating & evidence shown verbatim from Natural Medicines

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

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

Although there has been interest in using oral Bifidobacterium lactis for RA, there is insufficient reliable information about the clinical effects of B. lactis for this condition.

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

It is unclear if oral B. lactis is beneficial for rotaviral diarrhea.

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

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

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

Oral Bifidobacterium lactis has only been evaluated in combination with other ingredients in adults and children; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Ventilator-associated pneumonia (VAP)
Rating & evidence shown verbatim from Natural Medicines

Oral Bifidobacterium lactis 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 people, B. lactis is considered generally safe when taken as directed. It has a long history of use in foods like yogurt.

People who should be more cautious include those with weakened immune systems, serious illness, those who are critically ill or hospitalized, and people with central venous catheters. In rare cases, probiotics have been linked to serious infections in these vulnerable groups. Premature infants should only receive probiotics under medical supervision.

For pregnancy and breastfeeding, probiotics are often considered low-risk, but solid safety data are limited. To be safe, talk with your doctor or pharmacist before using it during these times.

Always choose products from reputable manufacturers, and check with a healthcare professional if you have ongoing digestive symptoms or a chronic health condition.

Side effects

Side effects are usually mild. The most common ones are gas, bloating, and mild stomach discomfort, especially during the first few days of use. These often settle as your body adjusts.

Serious side effects are rare in healthy people. In individuals who are seriously ill or have weakened immune systems, there is a small risk of more serious infections. If you develop fever, severe abdominal pain, or feel very unwell after starting a probiotic, stop using it and seek medical care.

Bifidobacterium Animalis Subsp. Lactis: Reported Adverse Effects

Documented safety reports on Bifidobacterium Animalis Subsp. Lactis from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Orally, Bifidobacterium lactis seems to be well tolerated by most patients.

Most Common Adverse Effects:

Orally: Diarrhea.

Serious Adverse Effects (Rare):

Orally: There is concern that probiotics may cause infections in some people.

Reports by condition
Constipation Gastrointestinal

Bloating and flatulence have been reported with probiotic use; however, these adverse effects have not been reported from ingestion of Bifidobacterium lactis in particular. When taken orally, B. lactis can cause diarrhea and other gastrointestinal complaints in children. Gastrointestinal complaints including worsening diarrhea, abdominal pain, constipation, stomach burn, and flatulence have been reported rarely.

  1. Phuapradit P, Varavithya W, Vathanophas K, et al. Reduction of rotavirus infection in children receiving bifidobacteria-supplemented formula. J Med Assoc Thai 1999;82:S43-8.
  2. Taipale TJ, Pienihäkkinen K, Isolauri E, Jokela JT, Söderling EM. Bifidobacterium animalis subsp. lactis BB-12 in reducing the risk of infections in early childhood. Pediatr Res. 2016;79(1-1):65-9.
  3. Amat-Bou M, Garcia-Ribera S, Climent E, et al. Effects of Bifidobacterium animalis Subsp. lactis (BPL1) supplementation in children and adolescents with prader-willi syndrome: A randomized crossover trial. Nutrients. 2020;12(10):3123.
  4. Mäkelä SM, Forssten SD, Kailajärvi M, et al. Effects of Bifidobacterium animalis ssp. lactis 420 on gastrointestinal inflammation induced by a nonsteroidal anti-inflammatory drug: A randomized, placebo-controlled, double-blind clinical trial. Br J Clin Ph
  5. Wildt S, Munck LK, Vinter-Jensen L, et al. Probiotic treatment of collagenous colitis: a randomized, double-blind, placebo-controlled trial with Lactobacillus acidophilus and Bifidobacterium animalis subsp. Lactis. Inflamm Bowel Dis 2006;12(5):395-401.
Pruritus Dermatologic

In clinical research, two cases of rash, one with itching, were reported by patients taking a combination of Bifidobacterium lactis BB-12, Lacticaseibacillus paracasei F19, and Lactobacillus acidophilus La5. However, it is not clear if these adverse effects were due to B. lactis, other probiotics, or the combination, or if the events were idiosyncratic.

  1. Begtrup LM, de Muckadell OB, Kjeldsen J, Christensen RD, Jarbøl DE. Long-term treatment with probiotics in primary care patients with irritable bowel syndrome--a randomised, double-blind, placebo controlled trial. Scand J Gastroenterol 2013;48(10):1127-35
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 standardized dose of B. lactis that works for everyone. Probiotic doses are usually measured in colony-forming units (CFU), and the amount varies widely between products.

The best approach is to follow the directions on the product label and start with the lowest suggested amount. Taking it consistently over time is often more important than the exact number.

If you are unsure which product or dose is right for you, ask your pharmacist. They can help you pick a reputable product and decide whether a probiotic is appropriate for your situation.

Pregnancy & Breastfeeding

Bifidobacterium Animalis Subsp. Lactis & Pregnancy

Insufficient reliable information

Insufficient reliable information available. A meta-analysis of four clinical trials shows that taking probiotics during pregnancy increases the relative risk of pre-eclampsia by 85% when compared with placebo. Although the specific effects of Bifidobacterium lactis are unclear from this analysis, three of the included studies used B. lactis in combination with Lacticaseibacillus rhamnosus. More information is needed to determine if certain patients are at increased risk.

Bifidobacterium Animalis Subsp. Lactis & Breastfeeding

Insufficient reliable information

Insufficient reliable information available. A meta-analysis of four clinical trials shows that taking probiotics during pregnancy increases the relative risk of pre-eclampsia by 85% when compared with placebo. Although the specific effects of Bifidobacterium lactis are unclear from this analysis, three of the included studies used B. lactis in combination with Lacticaseibacillus rhamnosus. More information is needed to determine if certain patients are at increased risk.

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 8 references that drive our Bifidobacterium Animalis Subsp. Lactis 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. Phuapradit P, Varavithya W, Vathanophas K, et al. Reduction of rotavirus infection in children receiving bifidobacteria-supplemented formula. J Med Assoc Thai 1999;82:S43-8.
  3. Xiao JZ, Takahashi S, Odamaki T, et al. Antibiotic susceptibility of bifidobacterial strains distributed in the Japanese market. Biosci Biotechnol Biochem. 2010;74(2):336-42. PubMed
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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

Bifidobacterium Animalis Subsp. Lactis: Common Questions

What is Bifidobacterium Animalis Subsp. Lactis used for, and does it work?
People use Bifidobacterium Animalis Subsp. Lactis for many reasons, but the evidence varies by use. According to the Natural Medicines database, there is at least some clinical evidence supporting Bifidobacterium Animalis Subsp. Lactis for Colic, Constipation, Irritable bowel syndrome (IBS) and Respiratory tract infections. 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 Bifidobacterium Animalis Subsp. Lactis interact with prescription medications?
Yes. We list 182 medications with a known interaction with Bifidobacterium Animalis Subsp. Lactis. Use the checker above to see how Bifidobacterium Animalis Subsp. Lactis interacts with a specific drug.
How are Bifidobacterium Animalis Subsp. Lactis 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 Bifidobacterium Animalis Subsp. Lactis 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 Bifidobacterium Animalis Subsp. Lactis 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 Bifidobacterium Animalis Subsp. Lactis used for?
It is a probiotic most commonly used to support digestion, improve bowel regularity, and help maintain a healthy balance of gut bacteria. Some people also use it for immune support, though that evidence is weaker.
Is it safe to take every day?
For most healthy people, daily use is generally well tolerated. If you have a weakened immune system or a serious illness, check with your doctor first, since probiotics may not be appropriate for everyone.
Can I get it from food instead of a supplement?
Yes. Many yogurts and fermented dairy products contain this probiotic. Check the label for the specific strain if you want to match what was used in research.
How long does it take to work?
It varies. Some people notice changes in digestion within a few days to a couple of weeks, while others may not notice a clear benefit. Consistent daily use is usually recommended.

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

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