Drug & supplement interaction

Lactobacillus Gasseri + Alosetron

Alosetron brand name: Lotronex.

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 Gasseri and Alosetron 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Lactobacillus Gasseri and Alosetron

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 Alosetron 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 Alosetron and Lactobacillus Gasseri? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Alosetron

Interactions in our licensed database are recorded against drug classes, not just single drug names. Alosetron is filed under 3 classifications — serotonergic drugs, serotonergic drugs, oral drugs. Lactobacillus Gasseri has documented interactions with 1 drug class — the most serious being antibiotic drugs (moderate) — and none of Alosetron’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 — Alosetron 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. Alosetron)
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

No Interaction Found — But Data Suggests Lactobacillus Gasseri and Alosetron May Share a Side Effect

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • A higher chance of infection Worth acting on Additional detail

    Lactobacillus Gasseri

    “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
    1. 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
    2. 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
    3. 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
    4. 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
    5. 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.
    6. 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

    Alosetron

    Listed in the ADVERSE REACTIONS section of the FDA label for Alosetron. Read the label on DailyMed ›

Effects for Alosetron come from the ADVERSE REACTIONS section of its FDA label; effects for Lactobacillus Gasseri come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Overlapping uses

What Alosetron 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. Alosetron 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.

Alosetron is prescribed for: Alosetron tablets — available as Alosetron, Alosetron Hydrochloride, and Lotronex — are approved only for women with severe diarrhea-predominant irritable bowel syndrome (IBS) whose symptoms have lasted 6 months or longer and who have not gotten adequate relief from conventional therapy. Other causes of GI symptoms must be ruled out first. To qualify as severe, diarrhea-predominant IBS must include diarrhea plus at least one of the following: frequent and severe abdominal pain or discomfort, frequent bowel urgency or fecal incontinence (accidental stool leakage), or significant disruption to daily activities. Clinical studies have not confirmed the same benefit in men.

Lactobacillus Gasseri has been studied for:

  • Diarrhea 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 diarrhea

    Oral Lactobacillus gasseri has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

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 Alosetron 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.

From our Q&A

Questions About Lactobacillus Gasseri or Alosetron

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Lactobacillus Gasseri or Alosetron, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Alosetron

This page covers Lactobacillus Gasseri only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Alosetron page lists 38 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Lithium (major), 5-htp (moderate), Acetyl-l-carnitine (moderate) and Ayahuasca (moderate).

By severity: 2 major · 25 moderate · 11 minor.

From our pharmacist’s overview on the Alosetron page

“Alosetron (Lotronex) treats severe diarrhea-predominant IBS by acting on serotonin receptors in the gut, and that is where most of its 38 supplement interactions come from. Twenty of the ingredients, 5-HTP among them, raise serotonin on their own, and stacking them on a serotonin-acting drug is a combination I want you to treat with re…”

Reviewed by 2 · Jul 18, 2026

Open the Alosetron 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 Alosetron, 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 Alosetron 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%

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

29 days ago today
Medication Alosetron
Steady interest

#1,755 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 Alosetron 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 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 Alosetron

What Is Alosetron Used For?

Brand name: Lotronex

Alosetron tablets — available as Alosetron, Alosetron Hydrochloride, and Lotronex — are approved only for women with severe diarrhea-predominant irritable bowel syndrome (IBS) whose symptoms have lasted 6 months or longer and who have not gotten adequate relief from conventional therapy. Other causes of GI symptoms must be ruled out first.

To qualify as severe, diarrhea-predominant IBS must include diarrhea plus at least one of the following: frequent and severe abdominal pain or discomfort, frequent bowel urgency or fecal incontinence (accidental stool leakage), or significant disruption to daily activities. Clinical studies have not confirmed the same benefit in men.

See full Alosetron 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 Alosetron, 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.

  1. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  2. Ramachandran L, Dontaraju VS, Patel K. Lactobacillus-associated spontaneous bacterial peritonitis in a liver cirrhosis patient on probiotics. Cureus. 2020;12(12):e11896. PubMed
  3. 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
  4. 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
  5. 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
  6. 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
  7. 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.
  8. 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
  9. 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.
  10. Esquibel A, Dababneh AS, Palraj BR. Lactobacillus gasseri causing bilateral empyema. Case Rep Infect Dis 2017;2017:4895619.
  11. 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
  12. 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 Alosetron Together: Common Questions

Is it safe to take Lactobacillus Gasseri with Alosetron?
We do not list a known interaction between Lactobacillus Gasseri and Alosetron. 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.
Do Lactobacillus Gasseri and Alosetron have any of the same side effects?
Yes — our sources link each of them separately to one of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Lactobacillus Gasseri and Alosetron 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 Alosetron is being adjusted to a target.
How was the Lactobacillus Gasseri and Alosetron combination checked?
Interactions in our licensed database are recorded against drug classes. Alosetron is filed under 3 classifications, and Lactobacillus Gasseri has documented interactions with 1 drug class — none of Alosetron'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 — Alosetron 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 Alosetron interact with any supplements?
Yes. Alosetron has documented interactions with 38 supplements in our database — Lactobacillus Gasseri is not one of them. The Alosetron 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 Alosetron drug information The full plain-English guide to this medication Alosetron supplement interactions Every supplement checked against Alosetron, 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 Alosetron and Lactobacillus Gasseri?

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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.