Interactions on record — worth a quick check against your medications. Based on 2 of 5 ingredients. Check your meds →
Dietary supplement

Cal'dophilus With FOS Ingredients & Drug Interactions

by Natural Factors

Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Cal'dophilus With FOS is a dietary supplement by Natural Factors with 5 active ingredients. Its ingredients are commonly taken for digestive health and regularity, irritable bowel syndrome (ibs), diarrhea (including antibiotic-related).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 longum, Lactobacillus acidophilus. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Cal'dophilus With FOS 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

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 5 of its 5 active ingredients.
  • “Total Active Cell count” is listed as a grouped ingredient — the label gives one combined amount (6,000,000,000 microorganisms) without saying how much of each component you get.

Cal'dophilus With FOS is a 5-ingredient probiotic blend. The active ingredients are two Lactobacillus species (acidophilus and casei), two Bifidobacterium species (longum and rhamnosus), and FOS (a prebiotic fiber that feeds beneficial bacteria).

These live microorganisms are intended to support digestive and intestinal health. The product also contains inactive ingredients—maltodextrin, calcium gluconate, gelatin capsule, pectin, magnesium stearate, and ascorbic acid—which are fillers and capsule materials.

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: promote digestive health with beneficial intestinal flora.
  • We looked for evidence on: Antibiotic-associated diarrhea, Bacterial vaginosis, Clostridioides difficile infection, Colic, Constipation, Diarrhea — 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, Helicobacter pylori, Irritable bowel syndrome (IBS).
  • Also on file: Lactobacillus Acidophilus is rated "Insufficient Reliable Evidence To Rate" for Constipation, Inflammatory bowel disease (IBD), Radiation-induced diarrhea.

The evidence for these ingredients is mixed. Lactobacillus acidophilus is rated Possibly Effective for irritable bowel syndrome, Helicobacter pylori infection, antibiotic-associated diarrhea, and bacterial vaginosis.

Bifidobacterium longum, however, shows Insufficient Reliable Evidence for the conditions we've rated it on—including antibiotic-associated diarrhea, age-related cognitive decline, allergic rhinitis, and asthma. We hold no effectiveness data for Lactobacillus casei, Lactobacillus rhamnosus, or FOS in our files.

The evidence, ingredient by ingredient Bifidobacterium Longum 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.

Both Bifidobacterium longum and Lactobacillus acidophilus are generally well tolerated in healthy people. However, caution is advised if you're seriously ill or have a weakened immune system—in rare cases, these bacteria have caused infection (bacteremia or sepsis) in critically ill infants and immune-compromised patients.

Orally, uncommon gastrointestinal side effects include abdominal discomfort, flatulence, bloating, and constipation. One person reported a dry cough.

For pregnancy and breastfeeding, Bifidobacterium longum is rated Possibly Safe, but we hold no safety data for Lactobacillus acidophilus during those periods, so ask your doctor or pharmacist for guidance.

Side effects, ingredient by ingredient Bifidobacterium Longum 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 Longum.
  • 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.

If you're on an antibiotic, separate it from this product—antibiotics can kill the live probiotics and reduce their effectiveness. Check your exact medications with the tool on this page, since the interactions span 182 individual drugs.

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.

This probiotic blend may help if you have irritable bowel syndrome, antibiotic-associated diarrhea, or certain bacterial infections—though evidence varies. If you're taking antibiotics, time this product separately to protect the live organisms.

Be cautious if you're seriously ill or immune-compromised, and talk with your pharmacist before using it during pregnancy or breastfeeding.

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

Assessment coverage: 2 of 5 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jun 1, 2012.

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 Cal'dophilus With FOS, straight from the product label.

Brand Natural Factors
Barcode (UPC) 068958018218
Net contents 90 Capsule(s)
Market status On market
Date entered into DSLD Jun 1, 2012
DSLD ID 8454
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
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 Cal'dophilus With FOS 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
068958018218
IngredientAmount% DV
Bifidobacterium longum600000000 {microorganisms}--
Lactobacillus acidophilus600000000 {microorganisms}--
Lactobacillus casei1800000000 {microorganisms}--
Lactobacillus rhamnosus3000000000 {microorganisms}--
FOS200 mg--
Total Active Cell count6000000000 {microorganisms}--

Other ingredients: Maltodextrin, Calcium Gluconate, 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.
Suggested/Recommended/Usage/Directions

Suggested Usage: To maintain healthful intestinal flora, take 1 capsule, 1-3 times per day, 15 minutes before meals or 1 hour after. When taking antibiotics, take probiotic 2 hours before or 2 hours after antibiotic.

Storage

FOR MAXIMUM POTENCY, REFRIGERATE

FDA Statement of Identity

DIETARY SUPPLEMENT

General Statements

PROBIOTIC FORMULA

Promotes well-being & digestive health with beneficial micro-flora

This synergistic combination supports intestinal tract health and contains FOS, an excellent growth factor for beneficial micro-flora. These cultures are freeze-dried to ensure long-term stability and maximum potency. All Natural Factors products are manufactured in accordance with the Government of Canada's Good Manufacturing Practices (GMP), among the highest standards in the world.

Colony counts are guaranteed at time of manufacture.

PRODUCT OF CANADA

Formula

6 BILLION ACTIVE CELLS

Contains dairy, soy.

Formulation

Contains no artificial preservatives, color or sweeteners; no wheat.

Precautions

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

Keep out of reach of children.

General

R4

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

(recycle) Recyclable container.

Purity & Potency Guaranteed

See for yourself

Cal'dophilus With FOS by Natural Factors label

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

What’s inside

The Ingredients in Cal'dophilus With FOS by Natural Factors

These are the 5 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.

FOS

200 mg per serving

Total Active Cell count

6000000000 {microorganisms} per serving

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

Interaction report

Cal'dophilus With FOS by Natural Factors Drug Interactions

Want to check YOUR meds against Cal'dophilus With FOS?

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

Each ingredient & the kinds of drugs it affects

For each ingredient in Cal'dophilus With FOS 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 longum1 drug type · 182 drugs

Antibiotic Drugs

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

Likelihood Probable Evidence D

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
The maker

Brand information

Manufacturer and brand details for Cal'dophilus With FOS, from the product label.

Natural Factors

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

Cal'dophilus With FOS by Natural Factors: Common Questions

Does Cal'dophilus With FOS by Natural Factors interact with any medications?
Yes. Based on its ingredients, Cal'dophilus With FOS 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?
Cal'dophilus With FOS contains 5 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 while I'm on an antibiotic?
Not at the same time. Antibiotics can kill the live bacteria in this probiotic, which defeats the purpose. Space out your doses—ask your pharmacist how far apart to take them for your specific antibiotic.
Is this safe if I'm pregnant or breastfeeding?
Bifidobacterium longum is rated Possibly Safe during pregnancy and lactation. We don't have safety data for the other probiotic strains in this formula, so check with your doctor or pharmacist for personalized advice.
What's FOS, and why is it in here?
FOS stands for fructooligosaccharides—it's a prebiotic fiber that feeds the beneficial bacteria in this product, helping them grow and thrive in your gut.
Will this give me gas or bloating?
Flatulence and bloating have been reported rarely with these probiotics, usually when taken with other probiotic species. Most people tolerate it well, but start with one capsule if you have a sensitive stomach.
Does this actually work for irritable bowel syndrome?
Lactobacillus acidophilus in this blend is rated Possibly Effective for IBS. Bifidobacterium longum, though, doesn't have enough reliable evidence for us to say either way—the research is still building.

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

Not sure if Cal'dophilus With FOS 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.

Cal'dophilus With FOS label
Sources

Sources & How We Checked

Cal'dophilus With FOS'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 36 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 Longum 21 references
  1. Ha GY, Yang CH, Kim H, Chong Y. Case of sepsis caused by Bifidobacterium longum. J Clin Microbiol 1999;37:1227-8.
  2. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  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
  4. Rautava S, Kainonen E, Salminen S, Isolauri E. Maternal probiotic supplementation during pregnancy and breast-feeding reduces the risk of eczema in the infant. J Allergy Clin Immunol. 2012;130(6):1355-60. PubMed
  5. 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.
  6. Pellonperä O, Vahlberg T, Mokkala K, et al. Weight gain and body composition during pregnancy: a randomised pilot trial with probiotics and/or fish oil. Br J Nutr. 2020 Nov 4:1-11. PubMed
  7. Pellonperä O, Mokkala K, Houttu N, et al. Efficacy of fish oil and/or probiotic intervention on the incidence of gestational diabetes mellitus in an at-risk group of overweight and obese women: A randomized, placebo-controlled, double-blind clinical trial PubMed
  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. 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
  10. Enomoto T, Sowa M, Nishimori K, et al. Effects of bifidobacterial supplementation to pregnant women and infants in the prevention of allergy development in infants and on fecal microbiota. Allergol Int 2014;63(4):575-85. PubMed
  11. US Food and Drug Administration (FDA). Dear Healthcare Provider Letter: Warning Regarding Use of Probiotics in Preterm Infants. September 2023. Available at: https://www.fda.gov/media/172606/download?attachment. Accessed November 1, 2023.
  12. Pillai A, Tan J, Paquette V, Panczuk J. Does probiotic bacteremia in premature infants impact clinically relevant outcomes? A case report and updated review of literature. Clin Nutr ESPEN. 2020;39:255-259. PubMed
  13. Sabaté JM, Iglicki F. Effect of Bifidobacterium longum 35624 on disease severity and quality of life in patients with irritable bowel syndrome. World J Gastroenterol 2022;28(7):732-744.
  14. Malaguarnera M, Greco F, Barone G, Gargante MP, Malaguarnera M, Toscano MA. Bifidobacterium longum with fructo-oligosaccharide (FOS) treatment in minimal hepatic encephalopathy: a randomized, double-blind, placebo-controlled study. Dig Dis Sci 2007;52(11) PubMed
  15. Zbinden A, Zbinden R, Berger C, Arlettaz R. Case series of Bifidobacterium longum bacteremia in three preterm infants on probiotic therapy. Neonatology 2015;107(1):56-9.
  16. Tamaki H, Nakase H, Inoue S, et al. Efficacy of probiotic treatment with Bifidobacterium longum 536 for induction of remission in active ulcerative colitis: A randomized, double-blinded, placebo-controlled multicenter trial. Dig Endosc 2016;28(1):67-74.
  17. Bertelli C, Pillonel T, Torregrossa A, et al. Bifidobacterium longum bacteremia in preterm infants receiving probiotics. Clin Infect Dis 2015;60(6):924-7. PubMed
  18. Esaiassen E, Cavanagh P, Hjerde E, Simonsen GS, Støen R, Klingenberg C. Bifidobacterium longum subspecies infantis bacteremia in 3 extremely preterm infants receiving probiotics. Emerg Infect Dis 2016;22(9):1664-6.
  19. Tena D, Losa C, Medina MJ, Sáez-Nieto JA. Peritonitis caused by Bifidobacterium longum: case report and literature review. Anaerobe 2014;27:27-30. PubMed
  20. Sangkanjanavanich S, Pradubpongsa P, Mitthamsiri W, Sangasapaviliya A, Boonpiyathad T. Bifidobacterium infantis 35624 efficacy in patients with uncontrolled asthma: A randomized placebo-controlled trial. Ann Allergy Asthma Immunol 2022;129(6):790-792. PubMed
  21. Wilson HL, Ong CW. Bifidobacterium longum vertebrodiscitis in a patient with cirrhosis and prostate cancer. Anaerobe 2017;47:47-50. PubMed

See these in context on the Bifidobacterium Longum 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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