Interactions on record — worth a quick check against your medications. Based on 2 of 3 ingredients. Check your meds →
Dietary supplement

Acidophilus & Bifidus Ingredients & Drug Interactions

by Natural Factors

Acidophilus & Bifidus label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Acidophilus & Bifidus against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Acidophilus & Bifidus is a dietary supplement by Natural Factors with 3 active ingredients. Its ingredients are commonly taken for digestive health and regularity, diarrhea (including antibiotic-related), irritable bowel syndrome (ibs) symptoms.Based on those ingredients, 182 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Bifidobacterium bifidum, Lactobacillus acidophilus. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Acidophilus & Bifidus by Natural Factors

Ask about any prescription or over-the-counter medication and we check it for interactions with Acidophilus & Bifidus by Natural Factors — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Acidophilus & Bifidus by Natural Factors

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 3 of its 3 active ingredients.
  • “Proprietary Synergistic Blend” is a proprietary blend — the label gives one combined amount (5,000,000,000 Unit(s)) without saying how much of each component you get.

Acidophilus & Bifidus contains three active probiotic (beneficial bacteria) ingredients: Bifidobacterium bifidum, Lactobacillus acidophilus, and Lactobacillus rhamnosus. These are live microorganisms intended to support your gut flora.

The product also contains inactive ingredients including lactose, whey, goat milk, gelatin, pectin, magnesium stearate, and ascorbic acid.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: intestinal tract health and beneficial micro-flora support.
  • We looked for evidence on: Antibiotic-associated diarrhea, Bacterial vaginosis, Clostridioides difficile infection, Colic, Constipation, Inflammatory bowel disease (IBD) — and 4 related terms.
  • The strongest evidence on file: Lactobacillus Acidophilus is rated "Possibly Effective" for Antibiotic-associated diarrhea (Natural Medicines).
  • Also on file: Lactobacillus Acidophilus is rated "Possibly Effective" for Bacterial vaginosis, Irritable bowel syndrome (IBS).
  • Also on file: Bifidobacterium Bifidum is rated "Possibly Effective" for Irritable bowel syndrome (IBS).

The evidence for these probiotics is mixed. Bifidobacterium bifidum and Lactobacillus acidophilus are both rated possibly effective for irritable bowel syndrome (IBS).

L. acidophilus is also possibly effective for Helicobacter pylori infection, antibiotic-associated diarrhea, and bacterial vaginosis. For other conditions listed — allergic rhinitis, anxiety, Alzheimer disease, and respiratory tract infections — the evidence is insufficient to rate, or the organism shows insufficient evidence.

We don't have effectiveness data on file for Lactobacillus rhamnosus.

The evidence, ingredient by ingredient Bifidobacterium Bifidum Lactobacillus Acidophilus

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

These probiotics are generally well tolerated in healthy people. However, those with weakened immune systems should check with their doctor first, since the safety data is limited.

Bloating and flatulence can occur with probiotics in general, though they haven't been specifically reported with B. bifidum alone. One case of vomiting and fever was reported in a child taking both B. bifidum and L. acidophilus together, but it's unclear if the probiotics caused it.

Rare cases of bacterial bloodstream infections (sepsis) have been reported with probiotics in critically ill patients, but these are uncommon and haven't been tied to B. bifidum specifically.

Side effects, ingredient by ingredient Bifidobacterium Bifidum Lactobacillus Acidophilus

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 2 of the 2 matched ingredients can interact with medications — Lactobacillus Acidophilus, Bifidobacterium Bifidum.
  • The most serious interaction on file is rated Moderate.
  • For scale: 182 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Separate antibiotic drugs (Moderate severity) from this supplement — antibiotics can kill the live bacteria in Acidophilus & Bifidus, reducing its effectiveness. If you take antibiotics, ask your pharmacist or doctor when to start this supplement after you finish them.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Consider this if you have IBS, want to protect your gut after antibiotics, or your doctor recommends probiotics for your situation. If you take antibiotics, space them apart from this supplement.

Anyone with a weakened immune system should talk to their doctor first. Check with your pharmacist before starting, especially if you're on other medications.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 2 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 27, 2014.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Acidophilus & Bifidus, straight from the product label.

Brand Natural Factors
Barcode (UPC) 068958018003
Net contents 90 Capsule(s)
Market status On market
Date entered into DSLD Oct 27, 2014
DSLD ID 38585
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Acidophilus & Bifidus by Natural Factors, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
UPC/BARCODE
068958018003
IngredientAmount% DV
Bifidobacterium bifidum500000000 {Unit(s)}--
Lactobacillus acidophilus500000000 {Unit(s)}--
Lactobacillus rhamnosus4000000000 {Unit(s)}--
Proprietary Synergistic Blend5000000000 {Unit(s)}--

Other ingredients: Lactose, Whey, Goat Milk, Gelatin Capsule, Pectin, Magnesium Stearate, Ascorbic Acid

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
FDA Statement of Identity

DIETARY SUPPLEMENT

Precautions

Keep out of the reach of children.

Sealed for your protection. Do not use if seal is broken.

May contain traces of soy from fermentation process.

Formula

This synergistic combination supports intestinal tract health and contains goat’s milk, an excellent growth factor for beneficial micro-flora.* These cultures are freeze-dried to ensure long-term stability and maximum potency.*

5 BILLION ACTIVE CELLS

May contain traces of soy from fermentation process.

General Statements

Manufactured by Natural Factors to ensure safety and potency in accordance with Good Manufacturing Practices (GMP) of the FDA and Health Canada.

Guaranteed minimum 5 billion active cells per capsule at expiry date. Guaranteed minimum 6.5 billion active cells per capsule at manufacture date.

PRODUCT OF CANADA

Recyclable container and label.

PROMOTES WELL-BEING & DIGESTIVE HEALTH WITH BENEFICIAL MICRO-FLORA*

Formulation

Contains no artificial colors, preservatives, or sweeteners; no starch, wheat, gluten, corn, egg, fish, shellfish, tree nuts, or GMOs.

Storage

For freshness, store in a cool, dry place.

FOR MAXIMUM POTENCY, REFRIGERATE.

FDA Disclaimer Statement

* This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Seals/Symbols

Purity & Potency Guaranteed

WITH GOAT MILK

General

R4

Suggested/Recommended/Usage/Directions

Suggested usage: 1 capsule 1–3 times per day, preferably 30 minutes after meals, or as directed by a health professional. If taking antibiotics, wait 2 hours before ingesting probiotics.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Acidophilus & Bifidus by Natural Factors label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Acidophilus & Bifidus label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Acidophilus & Bifidus by Natural Factors

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Proprietary Synergistic Blend

5000000000 {Unit(s)} per serving

Other (inactive) ingredients: Lactose, Whey, Goat Milk, Gelatin Capsule, Pectin, Magnesium Stearate, Ascorbic Acid. These complete the product’s ingredient list but are not active constituents.

Interaction report

Acidophilus & Bifidus by Natural Factors Drug Interactions

Want to check YOUR meds against Acidophilus & Bifidus?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
182Drugs
182 Moderate

Ingredients driving the most interactions

Bifidobacterium bifidum 182
Lactobacillus acidophilus 182

Individual Drug Interactions

The ingredients in Acidophilus & Bifidus interact with 182 drugs. Click any drug to see the details.

2 of the 3 ingredients in Acidophilus & Bifidus interact with drugs. Each result below shows which ingredient is responsible. Bifidobacterium bifidum Lactobacillus acidophilus

Each ingredient & the kinds of drugs it affects

For each ingredient in Acidophilus & Bifidus with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Bifidobacterium bifidum1 drug type · 182 drugs

Antibiotic Drugs

Theoretically, taking Bifidobacterium. bifidum with antibiotic drugs might decrease the effectiveness of B. bifidum.
Since B. bifidum 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. bifidum preparations by at least 2 hours.

Likelihood Probable Evidence D
Bifidobacterium bifidum full monograph & interactions

Lactobacillus acidophilus1 drug type · 182 drugs

Antibiotic Drugs

Theoretically, taking Lactobacillus acidophilus with antibiotic drugs might decrease the effectiveness of L. acidophilus.
L. acidophilus 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. acidophilus preparations by at least two hours.

Likelihood Probable Evidence D
Lactobacillus acidophilus full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Acidophilus & Bifidus, from the product label.

Natural Factors

See all Natural Factors products
Name
Natural Factors Canada
Pharmacist Counseling Corner

Acidophilus & Bifidus by Natural Factors: Common Questions

Does Acidophilus & Bifidus by Natural Factors interact with any medications?
Yes. Based on its ingredients, Acidophilus & Bifidus has a known interaction with 182 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Acidophilus & Bifidus contains 3 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take this with antibiotics?
Not at the same time. Antibiotics can kill the live bacteria in this supplement, making it less effective. Space them out — your pharmacist or doctor can tell you exactly when to take each one.
Does it really help with IBS?
The two main ingredients here, Bifidobacterium bifidum and Lactobacillus acidophilus, are both rated possibly effective for IBS based on the evidence we hold. That means there's some research support, but it's not a guarantee for every person.
Is it safe if I have a weak immune system?
The data is limited, so you should check with your doctor before taking this if your immune system is compromised. These live organisms can theoretically cause issues in people with severely weakened immunity.
What are the side effects?
Bloating and flatulence are possible with probiotic use in general, though not specifically reported for one of the main ingredients here. Gastrointestinal discomfort like abdominal pain or burping can happen, but these are uncommon. One case of vomiting and fever was reported in a child, but it's unclear if the probiotics were the cause.
Is it safe during pregnancy?
Both Bifidobacterium bifidum and Lactobacillus acidophilus are rated possibly safe in pregnancy. That said, check with your doctor or pharmacist before starting any supplement when you're pregnant — they know your full picture.
What's in the capsule besides the bacteria?
The inactive ingredients are lactose, whey, goat milk, gelatin, pectin, magnesium stearate, and ascorbic acid. If you're allergic to any of these — especially dairy products — check the label carefully.

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

Not sure if Acidophilus & Bifidus is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Acidophilus & Bifidus label
Go deeper

The Full Monographs Behind Acidophilus & Bifidus’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Bifidobacterium Bifidum

Interacts with 182 drugs

Bifidobacterium bifidum is a 'friendly' bacteria (probiotic) that naturally lives in the human gut and is taken to support digestion and gut balance. Some evidence suggests probiotics may he...

Read the full Bifidobacterium Bifidum monograph → Herb & supplement monograph

Lactobacillus Acidophilus

Interacts with 182 drugs

Lactobacillus acidophilus is a 'friendly' bacterium used as a probiotic to support gut and vaginal health. It is generally well tolerated in healthy people, and there is reasonable evidence...

Read the full Lactobacillus Acidophilus monograph →
Sources

Sources & How We Checked

Acidophilus & Bifidus's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 22 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Bifidobacterium Bifidum 7 references
  1. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  2. 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
  3. Rerksuppaphol S, Rerksuppaphol L. Randomized controlled trial of probiotics to reduce common cold in schoolchildren. Pediatr Int. 2012;54(5):682-7. PubMed
  4. Karamali M, Dadkhah F, Sadrkhanlou M, et al. Effects of probiotic supplementation on glycaemic control and lipid profiles in gestational diabetes: a randomized, double-blind, placebo-controlled trial. Diabetes Metab 2016;42(4):234-41. PubMed
  5. Badehnoosh B, Karamali M, Zarrati M, et al. The effects of probiotic supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in gestational diabetes. J Matern Fetal Neonatal Med. 2018 May;31(9):1128-1136.
  6. Pruccoli G, Silvestro E, Pace Napoleone C, Aidala E, Garazzino S, Scolfaro C. Are probiotics safe? Bifidobacterium bacteremia in a child with severe heart failure. Infez Med. 2019;27(2):175-178.
  7. Esaiassen E, Hjerde E, Cavanagh JP, Simonsen GS, Klingenberg C; Norwegian Study Group on Invasive Bifidobacterial Infections. Bifidobacterium bacteremia: Clinical characteristics and a genomic approach to assess pathogenicity. J Clin Microbiol. 2017;55(7) PubMed

See these in context on the Bifidobacterium Bifidum monograph →

Lactobacillus Acidophilus 15 references
  1. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  2. 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 PubMed
  3. Chatterjee S, Kar P, Das T, Ray S, Gangulyt S, Rajendiran C, Mitra M. Randomised placebo-controlled double blind multicentric trial on efficacy and safety of Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 for prevention of antibiotic-associated
  4. Shavakhi A, Tabesh E, Yaghoutkar A, Hashemi H, Tabesh F, Khodadoostan M,Minakari M, Shavakhi S, Gholamrezaei A. The effects of multistrain probiotic compound on bismuth-containing quadruple therapy for Helicobacter pylori infection: a randomized placebo-c
  5. Karamali M, Dadkhah F, Sadrkhanlou M, et al. Effects of probiotic supplementation on glycaemic control and lipid profiles in gestational diabetes: a randomized, double-blind, placebo-controlled trial. Diabetes Metab 2016;42(4):234-41. PubMed
  6. Badehnoosh B, Karamali M, Zarrati M, et al. The effects of probiotic supplementation on biomarkers of inflammation, oxidative stress and pregnancy outcomes in gestational diabetes. J Matern Fetal Neonatal Med. 2018 May;31(9):1128-1136.
  7. Kumar S, Kumar R, Rohilla L, Jacob N, Yadav J, Sachdeva N. A high potency multi-strain probiotic improves glycemic control in children with new-onset type 1 diabetes mellitus: A randomized, double-blind, and placebo-controlled pilot study. Pediatr Diabete
  8. Shahriari A, Karimi E, Shahriari M, Aslani N, Khooshideh M, Arab A. The effect of probiotic supplementation on the risk of gestational diabetes mellitus among high-risk pregnant women: A parallel double-blind, randomized, placebo-controlled clinical trial PubMed
  9. Xiao SD, Zhang DZ, Lu H, et al. Multicenter, randomized, controlled trial of heat-killed Lactobacillus acidophilus LB in patients with chronic diarrhea. Adv Ther. 2003;20(5):253-60.
  10. 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. PubMed
  11. Ozer M, Goksu SY, Shahverdiani A, Mustafa M. Lactobacillus acidophilus-induced endocarditis and associated splenic abscess. Case Rep Infect Dis 2020;2020:1382709.
  12. Sadrin S, Sennoune S, Gout B, et al. A 2-strain mixture of Lactobacillus acidophilus in the treatment of irritable bowel syndrome: A placebo-controlled randomized clinical trial. Dig Liver Dis 2020;52(5):534-540. PubMed
  13. Stoffer JN, Slingsby TJ, Giuliari GP. Lactobacillus acidophilus endophthalmitis after intravitreal bevacizumab injection requiring intraocular lens explantation. Can J Ophthalmol 2022;57(1):e21-e22. PubMed
  14. Cukovic-Cavka S, Likic R, Francetic I, Rustemovic N, Opacic M, Vucelic B. Lactobacillus acidophilus as a cause of liver abscess in a NOD2/CARD15-positive patient with Crohn's disease. Digestion 2006;73(2-3):107-10.
  15. Hui J, Ren Y, Wang Y, Han Q. Lactobacillus acidophilus endophthalmitis postcataract operation: A case report with a literature review. Ocul Immunol Inflamm 2023.

See these in context on the Lactobacillus Acidophilus monograph →

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

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