Drug & supplement interaction

Lactobacillus Gasseri + Omalizumab

Omalizumab brand name: Xolair.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 20, 2026

The bottom line No known interaction

We found no known interaction between Lactobacillus Gasseri 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.

Know someone taking this? Share

Facebook Post Reddit Email

On this page

Interaction report

Lactobacillus Gasseri 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 Gasseri 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 Gasseri safety at a glance

Lactobacillus Gass... overall Use caution Generally well tolerated in healthy adults, but evidence is limited and some people should avoid it.

Pregnancy Use caution Not enough reliable safety data; use only with a doctor's guidance.

Breastfeeding Use caution Limited safety information, so check with your doctor before using.

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

Still wondering about combining Omalizumab and Lactobacillus Gasseri? 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 Gasseri 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 Gasseri Does Interact With Other Medications

Lactobacillus Gasseri 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 Gasseri

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

What to actually watch for

What Lactobacillus Gasseri Itself Has Been Linked To

This is not an interaction — nothing below involves Omalizumab. It is the side-effect record for Lactobacillus Gasseri on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Lactobacillus Gasseri, 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
“Since Lactobacillus gasseri preparations contain live and active microorganisms, there is some concern that they might cause pathogenic infection in some patients. Some lactobacilli species have been isolated in cases of bacteremia, sepsis, splenic abscess, endocarditis, necrotizing fasciitis, pancreatic necrosis, and meningoencephalitis.”

Lactobacillus Gasseri · Natural Medicines adverse-effect record, reported in cirrhosis.
6 sources cited

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

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

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

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

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.

112579. Ramos-Coria D, Canto-Losa J, Carrillo-Vázquez D, Carbajal-Morelos L, Estrada-León R, Corona-Rodarte E. Lactobacillus gasseri liver abscess and bacteremia: a case report. BMC Infect Dis 2021;21(1):518. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Lactobacillus Gasseri — 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.

Overlapping uses

What Omalizumab Is Prescribed For, and What Lactobacillus Gasseri Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Omalizumab is a prescription medicine with approved uses on its FDA label. Lactobacillus Gasseri is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Omalizumab is prescribed for: 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.

Read the rest of what Omalizumab is prescribed for

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.

Lactobacillus Gasseri has been studied for:

Asthma studied, not established Lactobacillus Gasseri has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

Lactobacillus Gasseri for asthma

It is unclear if oral Lactobacillus gasseri is beneficial for asthma.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Omalizumab on your own; if you are taking Lactobacillus Gasseri for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Omalizumab

This page covers Lactobacillus Gasseri 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 Gasseri as Part of a Dietary Supplement Product? Check It for Interactions

We hold 852 real supplement products containing Lactobacillus Gasseri, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lactobacillus Gasseri. Even though Lactobacillus Gasseri 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 Gasseri 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 Gasseri

Top 25%

#317 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 Gasseri reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Lactobacillus Gasseri 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 Dr. Brian Staiger, PharmD, BCPS.

Supplement

About Lactobacillus Gasseri

What is Lactobacillus Gasseri?

Digestive health
Weight and belly fat management
Vaginal and urinary health
Bloating and gut discomfort
General immune support

Lactobacillus gasseri is a 'friendly' probiotic bacterium found naturally in the human gut, mouth, and vaginal tract, and in some fermented foods. Early research suggests it may help with digestion, weight management, and vaginal health, but the evidence is limited and far from conclusive. It is generally well tolerated in healthy people, but anyone who is pregnant, breastfeeding, or has a weakened immune system should talk to a pharmacist or doctor first.

Lactobacillus gasseri · Lactobacillaceae · Live bacterial cells (probiotic strain) · Capsules, tablets, powders, fermented dairy products, and combination probiotic supplements

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

Lactobacillus Gasseri: dosing

There is no official standardized dose of L. gasseri. Probiotic amounts are usually measured in colony-forming units (CFUs), and products vary widely.The best approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Lactobacillus Gasseri 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 Gasseri

Browse every other medication we’ve checked against Lactobacillus Gasseri — 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 Gasseri page.

No interaction 2,647 drugs checked — show the list

We also checked Lactobacillus Gasseri 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 Gasseri list.

See the full Lactobacillus Gasseri interactions page

See every supplement checked against Omalizumab, ranked by severity

Evidence & sources

Lactobacillus Gasseri References

The 12 references that drive our Lactobacillus Gasseri 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.

Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
Ramachandran L, Dontaraju VS, Patel K. Lactobacillus-associated spontaneous bacterial peritonitis in a liver cirrhosis patient on probiotics. Cureus. 2020;12(12):e11896. PubMed
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
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
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
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
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.
Ramos-Coria D, Canto-Losa J, Carrillo-Vázquez D, Carbajal-Morelos L, Estrada-León R, Corona-Rodarte E. Lactobacillus gasseri liver abscess and bacteremia: a case report. BMC Infect Dis 2021;21(1):518. PubMed
Elikowski W, Malek-Elikowska M, Lisiecka M, Bodora A, Wisniewska K, Oko-Sarnowska Z. Lactobacillus gasseri endocarditis on the aortic valve bioprosthesis - a case report. Pol Merkur Lekarski 2017;43(257):220-223.
Esquibel A, Dababneh AS, Palraj BR. Lactobacillus gasseri causing bilateral empyema. Case Rep Infect Dis 2017;2017:4895619.
Tleyjeh IM, Routh J, Qutub MO, Lischer G, Liang KV, Baddour LM. Lactobacillus gasseri causing Fournier's gangrene. Scand J Infect Dis 2004;36(6-7):501-3. PubMed
Dickgiesser U, Weiss N, Fritsche D. Lactobacillus gasseri as the cause of septic urinary infection. Infection 1984;12(1):14-6. 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 Gasseri and Omalizumab Together: Common Questions

Is it safe to take Lactobacillus Gasseri with Omalizumab?

We do not list a known interaction between Lactobacillus Gasseri 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.

Are Lactobacillus Gasseri and Omalizumab used for the same thing?

They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Lactobacillus Gasseri in each. That is a conversation for your prescriber, especially if Omalizumab is being adjusted to a target.

How was the Lactobacillus Gasseri and Omalizumab combination checked?

Interactions in our licensed database are recorded against drug classes. Omalizumab is filed under 1 classification, and Lactobacillus Gasseri 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 Gasseri interact with any other medications?

Yes. Lactobacillus Gasseri 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 Gasseri 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 Gasseri 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 12 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Omalizumab and Lactobacillus Gasseri?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.