Drug & supplement interaction

Lactobacillus Crispatus + Omalizumab

Omalizumab brand name: Xolair.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Lactobacillus Crispatus and Omalizumab in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Lactobacillus Crispatus and Omalizumab

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Omalizumab and Lactobacillus Crispatus in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Lactobacillus Crispatus safety at a glance

Lactobacillus Cris... overall Use caution Generally considered safe for healthy people, but quality and evidence vary by product.
Pregnancy Use caution Limited safety data; use only under the guidance of your doctor.
Breastfeeding Use caution Not well studied during breastfeeding; check with your doctor first.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Omalizumab and Lactobacillus Crispatus? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Omalizumab

Interactions in our licensed database are recorded against drug classes, not just single drug names. Omalizumab is filed under a single classification — immunosuppressants. Lactobacillus Crispatus has documented interactions with 1 drug class — the most serious being antibiotic drugs (moderate) — and none of Omalizumab’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Lactobacillus Crispatus Does Interact With Other Medications

Lactobacillus Crispatus has 182 moderate known drug interactions in our database — Omalizumab isn’t one of them. If you take anything else, check it against the full list below.

Moderate 182 No known interaction 2,648 (incl. Omalizumab)
Taking anything else?

Check Another of Your Medications Against Lactobacillus Crispatus

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

What to actually watch for

What Lactobacillus Crispatus Itself Has Been Linked To

This is not an interaction — nothing below involves Omalizumab. It is the side-effect record for Lactobacillus Crispatus on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Lactobacillus Crispatus, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • A higher chance of infection Worth acting on Additional detail

    “Orally, taking Lactobacillus crispatus has rarely caused a swollen tongue and epiglottis.

    Since Lactobacillus crispatus preparations contain live and active microorganisms, there is some concern that they might cause pathogenic infection in some patients.”

    Lactobacillus Crispatus · Natural Medicines adverse-effect record, reported in sepsis.

    6 sources cited
    1. 110945. DE Leo V, Lazzeri E, Governini L, et al. Vaginal colonization of women after oral administration of Lactobacillus crispatus strain NTCVAG04 from the human microbiota. Minerva Obstet Gynecol 2022. PubMed
    2. 107543. 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
    3. 110917. Ranchal P, Gupta R, Goldberg R, A Lobo S, Pascual A, El Khoury MY. Penicillin-sensitive Lactobacillus jensenii bacteremia. Am J Ther 2021;28(2):e250-e252. PubMed
    4. 110918. Grazioli-Gauthier L, Rigamonti E, Leo LA, Martinetti Lucchini G, Lo Priore E, Bernasconi E. Lactobacillus jensenii mitral valve endocarditis: Case report, literature review and new perspectives. IDCases 2022;27:e01401. PubMed
    5. 110920. Toprak NU, Bozan T, Yilmaz S, Buyukbayrak EE, Tigen ET. Polymicrobial bacteremia due to Lactobacillus jensenii and Veillonella montpellierensis in a pregnant patient; case report and review of literature. Anaerobe 2022;75:102576. PubMed
    6. 110921. Chazan B, Raz R, Shental Y, Sprecher H, Colodner R. Bacteremia and pyelonephritis caused by Lactobacillus jensenii in a patient with urolithiasis. Isr Med Assoc J 2008;10(2):164-5.
  • Bloating or gas / Nausea Additional detail

    “Orally, taking Lactobacillus crispatus has rarely caused nausea, gas, and flatulence in clinical research.”

    Lactobacillus Crispatus · Natural Medicines adverse-effect record, reported in flatulence.

    2 sources cited
    1. 110942. DI Pierro F, Criscuolo AA, Dei Giudici A, et al. Oral administration of Lactobacillus crispatus M247 to papillomavirus-infected women: results of a preliminary, uncontrolled, open trial. Minerva Obstet Gynecol 2021;73(5):621-631. PubMed
    2. 110946. Dellino M, Cascardi E, Laganà AS, et al. Lactobacillus crispatus M247 oral administration: Is it really an effective strategy in the management of papillomavirus-infected women?. Infect Agent Cancer 2022;17(1):53. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Lactobacillus Crispatus — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Omalizumab’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Omalizumab column appears here.

Everything else you take

See Every Supplement That Interacts With Omalizumab

This page covers Lactobacillus Crispatus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Omalizumab page lists 53 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Active Hexose Correlated Compound (ahcc) (moderate), Alfalfa (moderate), American Ginseng (moderate), Andrographis (moderate) and Ashwagandha (moderate).

By severity: 52 moderate · 1 minor.

From our pharmacist’s overview on the Omalizumab page

“None of the 53 supplements on file for omalizumab (Xolair) carries a major rating, so this is a list to read with steady attention rather than alarm. Xolair treats allergic asthma and chronic hives by calming part of the immune system, and every entry here pulls the other way: these are immune-stimulating products, echinacea and astrag…”

Reviewed by 2 · Jul 18, 2026

Open the Omalizumab interaction page

One more smart check

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

We hold 48 real supplement products containing Lactobacillus Crispatus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lactobacillus Crispatus. Even though Lactobacillus Crispatus itself has no known interaction with Omalizumab, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Lactobacillus Crispatus and Omalizumab 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 Crispatus
Top half

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

29 days ago today
Medication Omalizumab
Steady interest

#1,463 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Lactobacillus Crispatus reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Lactobacillus Crispatus and Omalizumab records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Lactobacillus Crispatus

What is Lactobacillus Crispatus?

  • Vaginal health support
  • Preventing recurrent bacterial vaginosis
  • Reducing recurrent urinary tract infections
  • Yeast infection support
  • General microbiome balance

Lactobacillus crispatus is a 'good' bacterium that naturally dominates a healthy vaginal microbiome and is sold as a probiotic, mainly for vaginal and urinary health. Early research is promising for preventing recurrent bacterial vaginosis and urinary tract infections, but evidence is still limited and product quality varies. Talk with your pharmacist or doctor before using it, especially if you are pregnant or have a weakened immune system.

Lactobacillus crispatus · Lactobacillaceae · Live bacterial cells (probiotic strain) · Oral capsules, vaginal capsules or suppositories, powders, some yogurts and fermented foods

An interaction check asks whether these two react with each other — it does not ask whether Lactobacillus Crispatus is a good idea for someone in your situation. Here is what our Lactobacillus Crispatus record says about it on its own.

Lactobacillus Crispatus: dosing

There is no single standardized dose of Lactobacillus crispatus. Probiotic doses are usually measured in colony-forming units (CFU), and the right amount can vary by product and by why you are using it.The best approach is to follow the directions on the product label for the specific oral or vaginal product you have chosen.

From our Lactobacillus Crispatus monograph — the full record covers uses, side effects and every documented interaction.

Read the full Lactobacillus Crispatus monograph & all interactions
Medication

About Omalizumab Injection

What Is Omalizumab Injection Used For?

Brand name: Xolair

Xolair is used for several allergy-driven conditions. It treats moderate to severe persistent asthma in adults and children 6 and older whose symptoms aren't controlled by inhaled steroids alone and who test positive for a year-round airborne allergen. It is also used as an add-on maintenance treatment for chronic rhinosinusitis with nasal polyps (ongoing sinus inflammation with polyp growths) in adults 18 and older who haven't responded well to nasal corticosteroids.

Xolair is also approved to reduce allergic reactions — including anaphylaxis — from accidental food exposure in adults and children aged 1 and older with IgE-mediated food allergy. It must be used alongside strict food avoidance, and it is not a substitute for emergency treatment like epinephrine. Finally, Xolair treats chronic spontaneous urticaria (persistent hives with no identified trigger) in adults and adolescents 12 and older who still have symptoms despite antihistamine treatment.

See full Omalizumab Injection drug information
Keep checking

Other Drugs & Lactobacillus Crispatus

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

0Major
182Moderate
0Minor
2,647No known interaction
182 Moderate 2,647 No interaction
Moderate

182 interactions

Showing 60 of 182 moderate interactions — see all 182 on the Lactobacillus Crispatus page.

No interaction 2,647 drugs checked — show the list

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

Showing the 60 most looked-up of 2,647 medications checked with no known interaction — see the full Lactobacillus Crispatus list.

See the full Lactobacillus Crispatus interactions page
See every supplement checked against Omalizumab, ranked by severity
Evidence & sources

Lactobacillus Crispatus References

The 9 references that drive our Lactobacillus Crispatus 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. 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
  3. Ranchal P, Gupta R, Goldberg R, A Lobo S, Pascual A, El Khoury MY. Penicillin-sensitive Lactobacillus jensenii bacteremia. Am J Ther 2021;28(2):e250-e252. PubMed
  4. Grazioli-Gauthier L, Rigamonti E, Leo LA, Martinetti Lucchini G, Lo Priore E, Bernasconi E. Lactobacillus jensenii mitral valve endocarditis: Case report, literature review and new perspectives. IDCases 2022;27:e01401. PubMed
  5. Toprak NU, Bozan T, Yilmaz S, Buyukbayrak EE, Tigen ET. Polymicrobial bacteremia due to Lactobacillus jensenii and Veillonella montpellierensis in a pregnant patient; case report and review of literature. Anaerobe 2022;75:102576. PubMed
  6. Chazan B, Raz R, Shental Y, Sprecher H, Colodner R. Bacteremia and pyelonephritis caused by Lactobacillus jensenii in a patient with urolithiasis. Isr Med Assoc J 2008;10(2):164-5.
  7. DI Pierro F, Criscuolo AA, Dei Giudici A, et al. Oral administration of Lactobacillus crispatus M247 to papillomavirus-infected women: results of a preliminary, uncontrolled, open trial. Minerva Obstet Gynecol 2021;73(5):621-631. PubMed
  8. DE Leo V, Lazzeri E, Governini L, et al. Vaginal colonization of women after oral administration of Lactobacillus crispatus strain NTCVAG04 from the human microbiota. Minerva Obstet Gynecol 2022. PubMed
  9. Dellino M, Cascardi E, Laganà AS, et al. Lactobacillus crispatus M247 oral administration: Is it really an effective strategy in the management of papillomavirus-infected women?. Infect Agent Cancer 2022;17(1):53. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Lactobacillus Crispatus and Omalizumab Together: Common Questions

Is it safe to take Lactobacillus Crispatus with Omalizumab?
We do not list a known interaction between Lactobacillus Crispatus and Omalizumab. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
How was the Lactobacillus Crispatus and Omalizumab combination checked?
Interactions in our licensed database are recorded against drug classes. Omalizumab is filed under 1 classification, and Lactobacillus Crispatus has documented interactions with 1 drug class — none of Omalizumab's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Lactobacillus Crispatus interact with any other medications?
Yes. Lactobacillus Crispatus has 182 documented drug interactions in our database — Omalizumab is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Omalizumab interact with any supplements?
Yes. Omalizumab has documented interactions with 53 supplements in our database — Lactobacillus Crispatus is not one of them. The Omalizumab interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Lactobacillus Crispatus monograph Uses, safety profile, and every drug interaction in one place Omalizumab Injection drug information The full plain-English guide to this medication Omalizumab supplement interactions Every supplement checked against Omalizumab, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 9 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Omalizumab and Lactobacillus Crispatus?

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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.