Drug & supplement interaction

Probiotics + Levothyroxine, Liothyronine

Levothyroxine, Liothyronine brand name: Armour Thyroid.

No Known Interaction

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Updated July 2026 · Pair last verified Sep 13, 2026

The bottom line No known interaction

We found no known interaction between Probiotics and Levothyroxine, Liothyronine 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

Probiotics and Levothyroxine, Liothyronine

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 Levothyroxine, Liothyronine and Probiotics 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.

Probiotics safety at a glance

Probiotics overall Use caution Generally well tolerated in healthy people, but those who are seriously ill or immunocompromised should use them only under medical guidance.

Pregnancy Possibly Safe When Lactobacillus acidophilus, Lacticaseibacillus casei, Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, Ligilactobacillus salivarius, Limosilacto... Read the full pregnancy detail

Breastfeeding Possibly Safe When Lacticaseibacillus paracasei, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus, and Bifidobacterium longum are used... Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Levothyroxine, Liothyronine and Probiotics? Ask Dr. Brian Staiger, PharmD, BCPS directly ›

How we checked

Why No Interaction Is Listed for Levothyroxine, Liothyronine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Levothyroxine, Liothyronine is filed under 3 classifications — including thyroid hormone, oral drugs. Probiotics has documented interactions with 2 drug classes — the most serious being antibiotic drugs (moderate) and antifungals (minor) — and none of Levothyroxine, Liothyronine’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

Probiotics Does Interact With Other Medications

Probiotics has 182 moderate, 40 minor known drug interactions in our database — Levothyroxine, Liothyronine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 182 Minor 40 No known interaction 2,608 (incl. Levothyroxine, Liothyronine)

Taking anything else?

Check Another of Your Medications Against Probiotics

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

What to actually watch for

What Probiotics Itself Has Been Linked To

This is not an interaction — nothing below involves Levothyroxine, Liothyronine. It is the side-effect record for Probiotics on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Probiotics, 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 many probiotic preparations contain live and active microorganisms, there is some concern that they might cause pathogenic infection in some patients. Bacteremia and sepsis have been reported in patients with indwelling or central venous catheters or patients who are severely ill and/or immunocompromised, including preterm infants, that were using probiotic products.”

Probiotics · Natural Medicines adverse-effect record, reported in prematurity.
6 sources cited

4380. Saxelin M, Chuang NH, Chassy B, et al. Lactobacilli and bacteremia in southern Finland 1989-1992. Clin Infect Dis 1996;22:564-6. PubMed

8561. MacGregor G, Smith AJ, Thakker B, Kinsella J. Yoghurt biotherapy: contraindicated in immunosuppressed patients? Postgrad Med J 2002;78:366-7. PubMed

13008. Land MH, Rouster-Stevens K, Woods CR, et al. Lactobacillus sepsis associated with probiotic therapy. Pediatrics 2005;115:178-81.

13070. De Groote MA, Frank DN, Dowell E, et al. Lactobacillus rhamnosus GG bacteremia associated with probiotic use in a child with short gut syndrome. Pediatr Infect Dis J 2005;24:278-80. PubMed

90298. Vahabnezhad E, Mochon AB, Wozniak LJ, Ziring DA. Lactobacillus bacteremia associated with probiotic use in a pediatric patient with ulcerative colitis. J Clin Gastroenterol. 2013;47(5):437-9. PubMed

102416. Pruccoli G, Silvestro E, Pace Napoleone C, Aidala E, Garazzino S, Scolfaro C. Are probiotics safe? Bifidobacterium bacteremia in a child with severe heart failure. Infez Med. 2019;27(2):175-178.
Bloating or gas / Stomach upset / Stomach pain / Diarrhea / Vomiting / Nausea Additional detail
“Orally, gastrointestinal adverse effects such as diarrhea, dyspepsia, abdominal pain, nausea, vomiting, bloating, belching, and flatulence have been reported rarely with probiotics (2,3169,16841,90235,90239,90271,90291,95381,107520,110846). See individual topics for details.”

Probiotics · Natural Medicines adverse-effect record, reported in diarrhea.
6 sources cited

2. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.

3169. Phuapradit P, Varavithya W, Vathanophas K, et al. Reduction of rotavirus infection in children receiving bifidobacteria-supplemented formula. J Med Assoc Thai 1999;82:S43-8.

16841. Miele E, Pascarella F, Giannetti E. et al. Effect of a probiotic preparation (VSL#3) on induction and maintenance of remission in children with ulcerative colitis. Am J Gastroenterol 2009;104:437-43. PubMed

90235. Beerepoot MA, ter Riet G, Nys S, van der Wal WM, de Borgie CA, de Reijke TM,Prins JM, Koeijers J, Verbon A, Stobberingh E, Geerlings SE. Lactobacilli vs antibiotics to prevent urinary tract infections: a randomized, double-blind, noninferiority trial in p DOI

90239. Chatterjee S, Kar P, Das T, Ray S, Gangulyt S, Rajendiran C, Mitra M. Randomised placebo-controlled double blind multicentric trial on efficacy and safety of Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 for prevention of antibiotic-associated

90271. Krag A, Munkholm P, Israelsen H, von Ryberg B, Andersen KK, Bendtsen F. Profermin is efficacious in patients with active ulcerative colitis--a randomized controlled trial. Inflamm Bowel Dis. 2013;19(12):2584-92. PubMed
Itching / A skin rash Additional detail
“Orally, probiotics have been reported to cause rare cases of rash, itching and redness, and dermatitis. See individual topics for details.”

Probiotics · Natural Medicines adverse-effect record, reported in dermatitis.
3 sources cited

90236. Begtrup LM, de Muckadell OB, Kjeldsen J, Christensen RD, Jarbøl DE. Long-term treatment with probiotics in primary care patients with irritable bowel syndrome--a randomised, double-blind, placebo controlled trial. Scand J Gastroenterol 2013;48(10):1127-35 PubMed

110848. Hanifi A, Culpepper T, Mai V, et al. Evaluation of Bacillus subtilis R0179 on gastrointestinal viability and general wellness: a randomised, double-blind, placebo-controlled trial in healthy adults. Benef Microbes 2015;6(1):19-27. PubMed

93707. Merenstein DJ, Smith KH, Scriven M, Roberts RF, Sanders ME, Petterson S. The study to investigate the potential benefits of probiotics in yogurt, a patient-oriented, double-blind, cluster-randomised, placebo-controlled, clinical trial. Eur J Clin Nutr. 20 PubMed

Everything above comes from the Natural Medicines adverse-effect record for Probiotics — expand a row for the licensed statement it rests on. We haven’t matched Levothyroxine, Liothyronine to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Levothyroxine, Liothyronine.

Special populations

Probiotics in Pregnancy & Breastfeeding

Pregnancy Possibly Safe

When Lactobacillus acidophilus, Lacticaseibacillus casei, Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, Ligilactobacillus salivarius, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus, Bifidobacterium bifidum, and Bifidobacterium longum are used orally and appropriately, short-term. See individual topics for details. There is insufficient reliable information available about the safety of other probiotics during pregnancy.

Lactation Possibly Safe

When Lacticaseibacillus paracasei, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus, and Bifidobacterium longum are used orally and appropriately, short-term. See individual topics for details. There is insufficient reliable information available about the safety of other probiotics during lactation.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Probiotics or Levothyroxine, Liothyronine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Probiotics or Levothyroxine, Liothyronine, 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 Levothyroxine, Liothyronine

This page covers Probiotics only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Levothyroxine, Liothyronine page lists 50 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Tiratricol (major), Acetyl-l-carnitine (moderate), Alpha-lipoic Acid (moderate) and Ascophyllum Nodosum (moderate).

By severity: 2 major · 39 moderate · 9 minor.

From our pharmacist’s overview on the Levothyroxine, Liothyronine page

“For anyone taking levothyroxine or liothyronine (Armour Thyroid), this list earns real caution, not just a passing glance. Most of these 50 ingredients pull in one of two directions.”

Reviewed by 2 · Jul 18, 2026

Open the Levothyroxine, Liothyronine interaction page

One more smart check

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

We hold 15 real supplement products containing Probiotics, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Probiotics. Even though Probiotics itself has no known interaction with Levothyroxine, Liothyronine, 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 Probiotics and Levothyroxine, Liothyronine 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 Probiotics

Top 25%

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

29 days ago today

Medication Levothyroxine, Liothyronine

Top 5%

#61 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 Probiotics reference on this page ↓
Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Probiotics and Levothyroxine, Liothyronine records this page draws on were last updated July 11, 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 Probiotics

What is Probiotics?

Digestive health and regularity
Antibiotic-associated diarrhea
Irritable bowel syndrome (IBS)
Vaginal and urinary health
Immune support
General gut microbiome balance

Probiotics are live 'friendly' microbes that may help certain digestive conditions, such as antibiotic-associated diarrhea and some cases of IBS, though benefits depend heavily on the specific strain and dose. They are generally well tolerated for healthy people but should be used with caution by those with serious illness or weakened immune systems. Talk with your pharmacist or doctor to pick a product that matches your goal.

Live microorganisms (bacteria and yeasts) · Capsules, tablets, powders, chewables, gummies, drops, and fermented foods (yogurt, kefir, kombucha, sauerkraut)

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

Probiotics: dosing

There is no single standardized dose for probiotics, because the right amount depends on the specific strain and the reason for use. Doses are often listed in colony-forming units (CFU), and products can range widely.The best approach is to follow the directions on the product label and choose a product whose strain has been studied for your specific goal. A pharmacist can help you match a product to your needs and check that it is appropriate for you. Store probiotics as directed—some require refrigeration to keep the organisms alive.

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

Read the full Probiotics monograph & all interactions

Medication

About Levothyroxine, Liothyronine

Most-Reported Side Effects for Levothyroxine, Liothyronine

From FAERS, the FDA’s public side-effect reporting system (15 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 4 reports

Asthenia 3 reports

Dizziness 3 reports

Arthralgia 2 reports

Disorientation 2 reports

Keep checking

Other Drugs & Probiotics

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

0Major

182Moderate

40Minor

2,607No known interaction

182 Moderate 40 Minor 2,607 No interaction

Moderate

182 interactions

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

Minor

40 interactions

No interaction 2,607 drugs checked — show the list

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

Showing the 60 most looked-up of 2,607 medications checked with no known interaction — see the full Probiotics list.

See the full Probiotics interactions page

See every supplement checked against Levothyroxine, Liothyronine, ranked by severity

Evidence & sources

Probiotics References

The 77 references that drive our Probiotics 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.

Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
Niault M, Thomas F, Prost J, et al. Fungemia due to Saccharomyces species in a patient treated with enteral Saccharomyces boulardii. Clin Infect Dis 1999;28:930.
Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
Phuapradit P, Varavithya W, Vathanophas K, et al. Reduction of rotavirus infection in children receiving bifidobacteria-supplemented formula. J Med Assoc Thai 1999;82:S43-8.
Pletinex M, Legein J, Vandenplas Y. Fungemia with Saccharomyces boulardii in a 1-year-old girl with protracted diarrhea. J Pediatr Gastroenterol Nutr 1995;21:113-5. DOI
Fredenucci I, Chomarat M, Boucaud C, et al. Saccharomyces boulardii fungemia in a patient receiving ultra-levure therapy. Clin Infect Dis 1998;27:222-3.
Elmer GW, McFarland LV, Surawicz CM, et al. Behaviour of Saccharomyces boulardii in recurrent Clostridium difficile disease patients. Aliment Pharmacol Ther 1999;13:1663-8.
Lewis SJ, Freedman AR. Review article: the use of biotherapeutic agents in the prevention and treatment of gastrointestinal disease. Aliment Pharmacol Ther 1998;12:807-22. PubMed
Saxelin M, Chuang NH, Chassy B, et al. Lactobacilli and bacteremia in southern Finland 1989-1992. Clin Infect Dis 1996;22:564-6. PubMed
Tynkkynen S, Singh KV, Varmanen P. Vancomycin resistance factor of Lactobacillus rhamnosus GG in relation to enterococcal vancomycin resistance (van) genes. Int J Food Microbiol 1998;41:195-204. PubMed
Klein G, Zill E, Schindler R, et al. Peritonitis associated with vancomycin-resistant Lactobacillus rhamnosus in a continuous ambulatory peritoneal dialysis patient; organism identification, antibiotic therapy, and case report. J Clin Microbiol 1998;36:
Kalima P, Masterton RG, Roddie PH, et al. Lactobacillus rhamnosus infection in a child following bone marrow transplant. J Infect 1996;32:165-7. PubMed
Goldin BR. Health Benefits of probiotics. Br J Nutr 1998;80:S203-7. DOI
Rautio M, Jousimies-Somer H, Kauma H, et al. Liver abscess due to Lactobacillus rhamnosus strain indistinguishable from L. rhamnosus strain GG. Clin Infect Dis 1999;28:1159-60.
Cesaro S, Chinello P, Rossi L, Zanesco L. Saccharomyces cerevisiae fungemia in a neutropenic patient treated with Saccharomyces boulardii. Support Care Cancer 2000;8:504-5. PubMed
MacGregor G, Smith AJ, Thakker B, Kinsella J. Yoghurt biotherapy: contraindicated in immunosuppressed patients? Postgrad Med J 2002;78:366-7. PubMed
Borriello SP, Hammes WP, Holzapfel W, et al. Safety of probiotics that contain lactobacilli or bifidobacteria. Clin Infect Dis 2003;36:775-80. PubMed
Marteau P, Seksik P. Tolerance of probiotics and prebiotics. J Clin Gastroenterol 2004;38:S67-9. PubMed
Land MH, Rouster-Stevens K, Woods CR, et al. Lactobacillus sepsis associated with probiotic therapy. Pediatrics 2005;115:178-81.
De Groote MA, Frank DN, Dowell E, et al. Lactobacillus rhamnosus GG bacteremia associated with probiotic use in a child with short gut syndrome. Pediatr Infect Dis J 2005;24:278-80. PubMed
Munoz P, Bouza E, Cuenca-Estrella M, et al. Saccharomyces cerevisiae fungemia: an emerging infectious disease. Clin Infect Dis 2005;40:1625-34. PubMed
Miele E, Pascarella F, Giannetti E. et al. Effect of a probiotic preparation (VSL#3) on induction and maintenance of remission in children with ulcerative colitis. Am J Gastroenterol 2009;104:437-43. PubMed
Xiao JZ, Takahashi S, Odamaki T, et al. Antibiotic susceptibility of bifidobacterial strains distributed in the Japanese market. Biosci Biotechnol Biochem. 2010;74(2):336-42. PubMed
Lherm, T., Monet, C., Nougiere, B., Soulier, M., Larbi, D., Le Gall, C., Caen, D., and Malbrunot, C. Seven cases of fungemia with Saccharomyces boulardii in critically ill patients. Intensive Care Med 2002;28(6):797-801. PubMed
Riquelme, A. J., Calvo, M. A., Guzman, A. M., Depix, M. S., Garcia, P., Perez, C., Arrese, M., and Labarca, J. A. Saccharomyces cerevisiae fungemia after Saccharomyces boulardii treatment in immunocompromised patients. J Clin.Gastroenterol. 2003;36(1):41- PubMed
Cherifi, S., Robberecht, J., and Miendje, Y. Saccharomyces cerevisiae fungemia in an elderly patient with Clostridium difficile colitis. Acta Clin Belg. 2004;59(4):223-224. PubMed
Beerepoot MA, ter Riet G, Nys S, van der Wal WM, de Borgie CA, de Reijke TM,Prins JM, Koeijers J, Verbon A, Stobberingh E, Geerlings SE. Lactobacilli vs antibiotics to prevent urinary tract infections: a randomized, double-blind, noninferiority trial in p DOI
Begtrup LM, de Muckadell OB, Kjeldsen J, Christensen RD, Jarbøl DE. Long-term treatment with probiotics in primary care patients with irritable bowel syndrome--a randomised, double-blind, placebo controlled trial. Scand J Gastroenterol 2013;48(10):1127-35 PubMed
Chatterjee S, Kar P, Das T, Ray S, Gangulyt S, Rajendiran C, Mitra M. Randomised placebo-controlled double blind multicentric trial on efficacy and safety of Lactobacillus acidophilus LA-5 and Bifidobacterium BB-12 for prevention of antibiotic-associated
Krag A, Munkholm P, Israelsen H, von Ryberg B, Andersen KK, Bendtsen F. Profermin is efficacious in patients with active ulcerative colitis--a randomized controlled trial. Inflamm Bowel Dis. 2013;19(12):2584-92. PubMed
Shavakhi A, Tabesh E, Yaghoutkar A, Hashemi H, Tabesh F, Khodadoostan M,Minakari M, Shavakhi S, Gholamrezaei A. The effects of multistrain probiotic compound on bismuth-containing quadruple therapy for Helicobacter pylori infection: a randomized placebo-c
Vahabnezhad E, Mochon AB, Wozniak LJ, Ziring DA. Lactobacillus bacteremia associated with probiotic use in a pediatric patient with ulcerative colitis. J Clin Gastroenterol. 2013;47(5):437-9. PubMed
Ellouze O, Berthoud V, Mervant M, Parthiot JP, Girard C. Septic shock due to Sacccaromyces boulardii. Med Mal Infect. 2016;46(2):104-105.
Merenstein DJ, Smith KH, Scriven M, Roberts RF, Sanders ME, Petterson S. The study to investigate the potential benefits of probiotics in yogurt, a patient-oriented, double-blind, cluster-randomised, placebo-controlled, clinical trial. Eur J Clin Nutr. 20 PubMed
Appel-da-Silva MC, Narvaez GA, Perez LRR, Drehmer L, Lewgoy J. Saccharomyces cerevisiae var. boulardii fungemia following probiotic treatment. Med Mycol Case Rep. 2017;18:15-7. PubMed
Atici S, Soysal A, Karadeniz Cerit K, et al. Catheter-related Saccharomyces cerevisiae Fungemia Following Saccharomyces boulardii Probiotic Treatment: In a child in intensive care unit and review of the literature. Med Mycol Case Rep. 2017;15:33-35. PubMed
Martin IW, Tonner R, Trivedi J, et al. Saccharomyces boulardii probiotic-associated fungemia: questioning the safety of this preventive probiotic's use. Diagn Microbiol Infect Dis. 2017;87(3):286-8. PubMed
Romanio MR, Coraine LA, Maielo VP, Abramczyc ML, Souza RL, Oliveira NF. Saccharomyces cerevisiae fungemia in a pediatric patient after treatment with probiotics. Rev Paul Pediatr 2017;35(3):361-4.
Roy U, Jessani LG, Rudramurthy SM, et al. Seven cases of Saccharomyces fungaemia related to use of probiotics. Mycoses 2017;60(6):375-380.
Taipale TJ, Pienihäkkinen K, Isolauri E, Jokela JT, Söderling EM. Bifidobacterium animalis subsp. lactis BB-12 in reducing the risk of infections in early childhood. Pediatr Res. 2016;79(1-1):65-9. PubMed
Pruccoli G, Silvestro E, Pace Napoleone C, Aidala E, Garazzino S, Scolfaro C. Are probiotics safe? Bifidobacterium bacteremia in a child with severe heart failure. Infez Med. 2019;27(2):175-178.
Sendil S, Shrimanker I, Mansoora Q, Goldman J, Nookala VK. Lactobacillus rhamnosus bacteremia in an immunocompromised renal transplant patient. Cureus. 2020;12(2):e6887. PubMed
Albarillo FS, Shah U, Joyce C, Slade D. Lactobacillus rhamnosus Infection: A single-center 4-year descriptive analysis. J Glob Infect Dis. 2020;12(3):119-123. PubMed
Pasala S, Singer L, Arshad T, Roach K. Lactobacillus endocarditis in a healthy patient with probiotic use. IDCases. 2020;22:e00915. PubMed
Agrawal S, Tuchman ES, Bruce MJ, Theodorou ME. Fatal Lactobacillus endocarditis in a patient with transcatheter aortic valve replacement. BMJ Case Rep. 2020;13(11):e236835.
Antoun M, Hattab Y, Akhrass FA, Hamilton LD. Uncommon pathogen, Lactobacillus, causing infective endocarditis: Case report and review. Case Rep Infect Dis. 2020;2020:8833948. PubMed
Ventoulis I, Sarmourli T, Amoiridou P, et al. Bloodstream infection by Saccharomyces cerevisiae in two COVID-19 patients after receiving supplementation of Saccharomyces in the ICU. J Fungi (Basel). 2020;6(3):98. PubMed
Shahriari A, Karimi E, Shahriari M, Aslani N, Khooshideh M, Arab A. The effect of probiotic supplementation on the risk of gestational diabetes mellitus among high-risk pregnant women: A parallel double-blind, randomized, placebo-controlled clinical trial 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
Franko B, Vaillant M, Recule C, Vautrin E, et al. Lactobacillus paracasei endocarditis in a consumer of probiotics. Med Mal Infect. 2013;43(4):171-3. PubMed
Campbell RE, Miller A, Afroze A. Native valve endocarditis secondary to Lactobacillus paracasei bacteremia. Consultant. 2020;60(9):27-8. DOI
Kato K, Funabashi N, Takaoka H, et al. Lactobacillus paracasei endocarditis in a consumer of probiotics with advanced and severe bicuspid aortic valve stenosis complicated with diffuse left ventricular mid-layer fibrosis. Int J Cardiol. 2016;224:157-161. PubMed
Sakurai Y, Watanabe T, Miura Y, et al. Clinical and bacteriologic characteristics of six cases of Bifidobacterium breve bacteremia due to probiotic administration in the neonatal intensive care unit. Pediatr Infect Dis J 2022;41(1):62-65. PubMed
Esaiassen E, Hjerde E, Cavanagh JP, Simonsen GS, Klingenberg C; Norwegian Study Group on Invasive Bifidobacterial Infections. Bifidobacterium bacteremia: Clinical characteristics and a genomic approach to assess pathogenicity. J Clin Microbiol. 2017;55(7) PubMed
Freedman KE, Hill JL, Wei Y, et al. Examining the gastrointestinal and immunomodulatory effects of the novel probiotic Bacillus subtilis DE111. Int J Mol Sci 2021;22(5):2453. PubMed
Hanifi A, Culpepper T, Mai V, et al. Evaluation of Bacillus subtilis R0179 on gastrointestinal viability and general wellness: a randomised, double-blind, placebo-controlled trial in healthy adults. Benef Microbes 2015;6(1):19-27. PubMed
Luo C, Peng S, Li M, Ao X, Liu Z. The efficacy and safety of probiotics for allergic rhinitis: A systematic review and meta-analysis. Front Immunol 2022;13:848279. PubMed
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
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
Tasli L, Mat C, De Simone C, Yazici H. Lactobacilli lozenges in the management of oral ulcers of Behçet's syndrome. Clin Exp Rheumatol. 2006;24(5 Suppl 42):S83-6.
Silva NLNV, Della Bona A, Cardoso M, et al. Lactobacillus brevis CD2 attenuates traumatic oral lesions induced by fixed orthodontic appliance: A randomized phase 2 trial. Orthod Craniofac Res. 2021;24(3):379-385.
Mäkelä SM, Forssten SD, Kailajärvi M, et al. Effects of Bifidobacterium animalis ssp. lactis 420 on gastrointestinal inflammation induced by a nonsteroidal anti-inflammatory drug: A randomized, placebo-controlled, double-blind clinical trial. Br J Clin Ph
Wildt S, Munck LK, Vinter-Jensen L, et al. Probiotic treatment of collagenous colitis: a randomized, double-blind, placebo-controlled trial with Lactobacillus acidophilus and Bifidobacterium animalis subsp. Lactis. Inflamm Bowel Dis 2006;12(5):395-401. PubMed
US Food and Drug Administration (FDA). Dear Healthcare Provider Letter: Warning Regarding Use of Probiotics in Preterm Infants. September 2023. Available at: https://www.fda.gov/media/172606/download?attachment. Accessed November 1, 2023.
Pillai A, Tan J, Paquette V, Panczuk J. Does probiotic bacteremia in premature infants impact clinically relevant outcomes? A case report and updated review of literature. Clin Nutr ESPEN. 2020;39:255-259. PubMed
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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 Probiotics and Levothyroxine, Liothyronine Together: Common Questions

Is it safe to take Probiotics with Levothyroxine, Liothyronine?

We do not list a known interaction between Probiotics and Levothyroxine, Liothyronine. 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 Probiotics and Levothyroxine, Liothyronine combination checked?

Interactions in our licensed database are recorded against drug classes. Levothyroxine, Liothyronine is filed under 3 classifications, and Probiotics has documented interactions with 2 drug classes — none of Levothyroxine, Liothyronine'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 Probiotics interact with any other medications?

Yes. Probiotics has 222 documented drug interactions in our database — Levothyroxine, Liothyronine 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 Levothyroxine, Liothyronine interact with any supplements?

Yes. Levothyroxine, Liothyronine has documented interactions with 50 supplements in our database — Probiotics is not one of them. The Levothyroxine, Liothyronine interaction page linked on this page lists every one, ranked by severity.

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.