Drug & supplement interaction

Lactobacillus Delbrueckii + Colistimethate

Colistimethate brand name: Coly-Mycin M.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Lactobacillus Delbrueckii has a moderate interaction with Colistimethate. Theoretically, taking Lactobacillus delbrueckii 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

Lactobacillus Delbrueckii and Colistimethate

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

Moderate

ANTIBIOTIC DRUGS

Why this applies to Colistimethate

Colistimethate falls under ANTIBIOTIC DRUGS — the group Lactobacillus Delbrueckii interacts with.

Theoretically, taking Lactobacillus delbrueckii with antibiotic drugs might decrease the effectiveness of L. delbrueckii.
Lactobacillus delbrueckii 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. delbrueckii 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 simple version: colistimethate is a strong antibiotic, and antibiotics don't know the difference between 'bad' bacteria and the 'friendly' bacteria in a probiotic like Lactobacillus delbrueckii. If the antibiotic is around when you take the probiotic, it can kill off a good chunk of those live organisms, so you may not get the benefit you were hoping for from the supplement.

Good news: this works against the probiotic, not against your treatment. Your colistimethate keeps doing its job, and it isn't 'activated' by these bacteria, so the antibiotic's effects and side effects shouldn't change. This concern is mostly based on how things work in theory. A common, easy fix is to separate them by at least two hours. Since colistimethate is given as an injection, check the timing with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
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

Lactobacillus Delbrueckii Also Interacts With Other Medications

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

Moderate 181 No known interaction 2,649 (incl. Colistimethate)
Taking anything else?

Check Another of Your Medications Against Lactobacillus Delbrueckii

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

Everything else you take

See Every Supplement That Interacts With Colistimethate

This page covers Lactobacillus Delbrueckii only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Colistimethate page lists 27 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Bacillus Coagulans (moderate), Bacillus Subtilis (moderate), Bifidobacterium Animalis Subsp. Lactis (moderate), Bifidobacterium Bifidum (moderate) and Bifidobacterium Breve (moderate).

By severity: 26 moderate · 1 minor.

Open the Colistimethate interaction page

One more smart check

Taking Lactobacillus Delbrueckii as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,200 real supplement products containing Lactobacillus Delbrueckii, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lactobacillus Delbrueckii. Your product may carry other ingredients that interact with Colistimethate too, on top of Lactobacillus Delbrueckii — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Lactobacillus Delbrueckii and Colistimethate 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 Lactobacillus Delbrueckii
Top 25%

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

29 days ago today
Medication Colistimethate
Steady interest

#2,409 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 Lactobacillus Delbrueckii

What is Lactobacillus Delbrueckii?

  • Digestive health
  • Lactose digestion support
  • Diarrhea
  • Gut microbiome balance
  • Immune support

Lactobacillus delbrueckii is a 'friendly' bacterium used in food fermentation and sold as a probiotic, often as part of multi-strain products. It is generally considered safe for healthy people, but solid human evidence for most specific health claims is limited. Talk to a pharmacist or doctor before using it, especially if you have a weakened immune system or serious illness.

Read the full Lactobacillus Delbrueckii monograph & all interactions
Medication

About Colistimethate Injection

What Is Colistimethate Injection Used For?

Brand name: Coly-Mycin M

Colistimethate for Injection is used to treat acute (sudden) or chronic (long-lasting) infections caused by specific gram-negative bacteria. It is particularly effective against Pseudomonas aeruginosa and is also used for infections caused by Escherichia coli, Klebsiella pneumoniae, and Enterobacter aerogenes.

It may be used to start treatment when a serious infection is suspected to be caused by gram-negative bacteria, even before lab results are back. It is not used for infections caused by Proteus or Neisseria bacteria.

See full Colistimethate Injection drug information
Keep checking

Other Drugs & Lactobacillus Delbrueckii

Browse every other medication we’ve checked against Lactobacillus Delbrueckii — 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
181 Moderate 2,648 No interaction
Moderate

181 interactions

Showing 60 of 181 moderate interactions — see all 181 on the Lactobacillus Delbrueckii page.

No interaction 2,648 drugs checked — show the list

We also checked Lactobacillus Delbrueckii against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,648 medications checked with no known interaction — see the full Lactobacillus Delbrueckii list.

See the full Lactobacillus Delbrueckii interactions page
See every supplement checked against Colistimethate, ranked by severity
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

Keep exploring
Lactobacillus Delbrueckii monograph › Uses, safety, and every drug interaction in one place Colistimethate supplement interactions › Every supplement checked against Colistimethate, ranked by severity Colistimethate Injection drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Lactobacillus Delbrueckii and Colistimethate Together: Common Questions

Can you take Lactobacillus Delbrueckii with Colistimethate?
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 Lactobacillus Delbrueckii and Colistimethate 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

Still Have a Question About Colistimethate and Lactobacillus Delbrueckii?

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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.