Drug & supplement interaction

Limosilactobacillus Fermentum + Cefazolin

Cefazolin brand name: Ancef.

Moderate Interaction
The bottom line Moderate

Limosilactobacillus Fermentum has a moderate interaction with Cefazolin. Theoretically, taking Limosilactobacillus fermentum with antibiotic drugs might decrease the effectiveness of L.

Read the full interaction report
SeverityModerate
LikelihoodProbable
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Limosilactobacillus Fermentum and Cefazolin

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTIBIOTIC DRUGS

Why this applies to Cefazolin

Cefazolin falls under ANTIBIOTIC DRUGS — the group Limosilactobacillus Fermentum interacts with.

Theoretically, taking Limosilactobacillus fermentum with antibiotic drugs might decrease the effectiveness of L. fermentum.
Limosilactobacillus fermentum 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. fermentum preparations by at least two hours.
Severity Moderate Likelihood Probable Evidence D

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..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the thing to keep in mind: this interaction runs in one direction. Cefazolin (Ancef) is an antibiotic, and its whole job is to kill bacteria. Limosilactobacillus fermentum is a probiotic made of live, friendly bacteria. So if the two overlap, the cefazolin can knock out a good chunk of the probiotic organisms, making the supplement less effective. It does not reduce how well cefazolin fights your infection, and it doesn't make cefazolin's side effects worse.

This concern is based on pharmacology rather than strong studies, so it's more of a theoretical heads-up. One practical note: cefazolin is given as an injection in clinics or hospitals, while the probiotic is taken by mouth, so spacing them out is easy. If you want to keep the probiotic working, just take it a couple hours apart and ask your pharmacist if timing matters for your situation.

References
  1. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Limosilactobacillus Fermentum Also Interacts With Other Medications

Limosilactobacillus Fermentum has 181 moderate known drug interactions in our database — the Cefazolin one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Limosilactobacillus Fermentum

Covers the 2,830 medications we’ve checked against Limosilactobacillus Fermentum. Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Cefazolin

This page covers Limosilactobacillus Fermentum only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Cefazolin page lists 43 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Asarabacca (major), Siberian Cocklebur (major), African Wild Potato (moderate), Aristolochia (moderate) and Bacillus Coagulans (moderate).

By severity: 2 major · 39 moderate · 2 minor.

From our pharmacist’s overview on the Cefazolin page

“Cefazolin (Ancef), an antibiotic given by injection, usually before surgery or for skin and bloodstream infections, carries 43 supplement interactions on file, and the two rated major are where I would start reading. Siberian cocklebur and asarabacca can each damage the kidneys, the same organ that clears cefazolin, and asarabacca is f…”

Reviewed by 2 · Jul 18, 2026

Open the Cefazolin interaction page

How much people look this up

Where Limosilactobacillus Fermentum and Cefazolin Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Limosilactobacillus Fermentum
Top half

#382 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Cefazolin
Steady interest

#1,666 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Limosilactobacillus Fermentum

What is Limosilactobacillus Fermentum?

  • Digestive health
  • Immune support
  • Vaginal and urinary health
  • Cholesterol support
  • Oral health

Limosilactobacillus fermentum (formerly Lactobacillus fermentum) is a probiotic bacterium found in fermented foods and the human body, used to support gut, immune, and women's health. Early research is promising for some uses but most evidence is preliminary, and effects can differ by strain. It is generally well tolerated in healthy people, but talk to your pharmacist or doctor before starting, especially if your immune system is weak.

Read the full Limosilactobacillus Fermentum monograph & all interactions
Medication

About Cefazolin Injection

What Is Cefazolin Injection Used For?

Brand name: Ancef

Cefazolin Injection is used to treat bacterial infections in adults and children 1 month of age and older, including respiratory tract infections, urinary tract infections, skin and skin structure infections, biliary tract infections, bone and joint infections, genital infections (such as prostatitis and epididymitis), septicemia (a serious bloodstream infection), and endocarditis (infection of the heart's inner lining).

It is also used in adult patients — and in pediatric patients aged 10 to 17 years for the premixed formulation — to help prevent infection around the time of surgery, particularly for procedures that carry a higher risk of postoperative infection.

See full Cefazolin Injection drug information
Keep checking

Other Drugs & Limosilactobacillus Fermentum

Browse every other medication we’ve checked against Limosilactobacillus Fermentum — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
181Moderate
0Minor
2,648No known interaction
Moderate

181 interactions

Showing 60 of 181 moderate interactions — see all 181 on the Limosilactobacillus Fermentum page.

No interaction 2,648 drugs checked — show the list
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

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

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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Pharmacist Counseling Corner

Taking Limosilactobacillus Fermentum and Cefazolin Together: Common Questions

Can you take Limosilactobacillus Fermentum with Cefazolin?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Limosilactobacillus Fermentum and Cefazolin interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

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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.