Probiotics and medications.
Probiotics is in the Distil supplement database, evidence Grade B. The page below lists every medication we have explicitly assessed it against.
Probiotics support gut microbiome diversity and immune signalling, but the headline rule is that the evidence is strain-specific. A product labelled only "multi-strain" without named strains tells you little. The strongest data sit with particular strains for particular jobs: Lactobacillus plantarum 299v for IBS, Saccharomyces boulardii for antibiotic-associated diarrhoea, and Lactobacillus rhamnosus GG for diarrhoea prevention, and we grade each of these Grade B, the same as general wellness. For IBS the picture is mixed rather than settled: Hungin 2013 rates the symptom-burden evidence highly, but a 2026 meta-analysis of 40 trials rates its own certainty low and says more trials are needed, and the meta-analysis covering multi-strain products specifically, which is the kind of product described here, found no significant effect on abdominal pain. For the diarrhoea claim the difficulty is that the yeast with the reputation is not one in our database, and the paper cited for it is a single-author review article about a different organism. A second Grade B claim is respiratory: a Cochrane review of 23 trials found that people taking probiotics tended to have fewer repeated colds, and were less likely to end up needing treatment for one from their GP, though the trials ran for more than three months and mostly used just one or two named strains. One claim our records do not support is mood. The psychobiotic idea rests on a review article and on a 22-person study of one specific strain, Bifidobacterium longum 1714, which we grade separately and more cautiously, so a general multi-strain capsule is not something we recommend for mood. Doses run from 10 to 50 billion CFU across at least five named species. The interactions are simple but important. Keep probiotics at least two hours apart from antibiotics, since taken together the antibiotic kills the live organisms. Prebiotic fibre such as inulin, FOS or psyllium feeds and sustains the colonisation. Some bloating on starting is normal and usually settles within a week or two.
Below are the 16 documented pairs we have explicitly assessed for Probiotics: 6 caution and 10 good to know. The pairs cluster around 2 mechanisms: Immunosuppression caution and Probiotic timing with antibiotics. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication into our next curation pass.
Documented interactions
Last reviewed 15 June 2026. Each interaction below lists the evidence its assessment drew on: some rest on studies of the exact pair, others on mechanism evidence, where a citation may support one part of the reasoning rather than the exact combination. The evidence line on each entry says which.
Immunosuppression caution
Caution Does Probiotics interact with Azathioprine?
If you take azathioprine, it is sensible to check with your specialist before starting a probiotic: azathioprine dampens the immune system, often for an autoimmune condition or after a transplant, and in people whose defences are significantly weakened there have been rare cases of the probiotic organism getting into the bloodstream and causing an infection. If you do take one, choose a bacterial probiotic rather than a yeast-based one such as Saccharomyces boulardii, which European medicine labels rule out when the immune system is weakened. If you are seriously unwell in hospital or have a central line (a long-term drip line into a large vein, such as a PICC), start a probiotic only if the team caring for you agrees. Probiotics are live bacteria or yeast, and the evidence that they are safe for most people comes from studies of people who were not significantly immunosuppressed, so on azathioprine let your specialist's advice decide.
Evidence: Supported by human study data.
Caution Does Probiotics interact with Ciclosporin?
If you take ciclosporin, check with your specialist team before starting a probiotic: ciclosporin strongly dampens the immune system, usually after a transplant or for a serious autoimmune condition, and in people whose defences are this weakened there have been rare cases of the probiotic organism getting into the bloodstream and causing an infection. If you do take one, choose a bacterial probiotic rather than a yeast-based one such as Saccharomyces boulardii, which European medicine labels rule out when the immune system is weakened. If you are seriously unwell in hospital or have a central line (a long-term drip line into a large vein, such as a PICC), start a probiotic only if the team caring for you agrees. Probiotics are live bacteria or yeast, and the evidence that they are safe for most people comes from studies of people who were not significantly immunosuppressed, so on ciclosporin let your specialist team's advice decide.
Evidence: Supported by human study data.
Caution Does Probiotics interact with Everolimus?
If you take everolimus, check with your specialist team before starting a probiotic: everolimus strongly dampens the immune system, used after a transplant or in some cancers, and in people whose defences are this weakened there have been rare cases of the probiotic organism getting into the bloodstream and causing an infection. If you do take one, choose a bacterial probiotic rather than a yeast-based one such as Saccharomyces boulardii, which European medicine labels rule out when the immune system is weakened. If you are seriously unwell in hospital or have a central line (a long-term drip line into a large vein, such as a PICC), start a probiotic only if the team caring for you agrees. Probiotics are live bacteria or yeast, and the evidence that they are safe for most people comes from studies of people who were not significantly immunosuppressed, so on everolimus let your specialist team's advice decide.
Evidence: Supported by human study data.
Caution Does Probiotics interact with Methotrexate?
If you take methotrexate, it is sensible to check with your specialist before starting a probiotic: methotrexate dampens the immune system, and in people whose defences are significantly weakened there have been rare cases of the probiotic organism getting into the bloodstream and causing an infection. At the usual low weekly doses for arthritis or psoriasis this risk is small. If you do take one, choose a bacterial probiotic rather than a yeast-based one such as Saccharomyces boulardii, which European medicine labels rule out when the immune system is weakened. If you are seriously unwell in hospital or have a central line (a long-term drip line into a large vein, such as a PICC), start a probiotic only if the team caring for you agrees. Probiotics are live bacteria or yeast, and the evidence that they are safe for most people comes from studies of people who were not significantly immunosuppressed, so on methotrexate let your specialist's advice decide.
Evidence: Supported by human study data.
Caution Does Probiotics interact with Sirolimus?
If you take sirolimus, check with your specialist team before starting a probiotic: sirolimus strongly dampens the immune system, usually after a transplant, and in people whose defences are this weakened there have been rare cases of the probiotic organism getting into the bloodstream and causing an infection. If you do take one, choose a bacterial probiotic rather than a yeast-based one such as Saccharomyces boulardii, which European medicine labels rule out when the immune system is weakened. If you are seriously unwell in hospital or have a central line (a long-term drip line into a large vein, such as a PICC), start a probiotic only if the team caring for you agrees. Probiotics are live bacteria or yeast, and the evidence that they are safe for most people comes from studies of people who were not significantly immunosuppressed, so on sirolimus let your specialist team's advice decide.
Evidence: Supported by human study data.
Caution Does Probiotics interact with Tacrolimus?
If you take tacrolimus, check with your specialist team before starting a probiotic: tacrolimus strongly dampens the immune system, usually after a transplant or for a serious autoimmune condition, and in people whose defences are this weakened there have been rare cases of the probiotic organism getting into the bloodstream and causing an infection. If you do take one, choose a bacterial probiotic rather than a yeast-based one such as Saccharomyces boulardii, which European medicine labels rule out when the immune system is weakened. If you are seriously unwell in hospital or have a central line (a long-term drip line into a large vein, such as a PICC), start a probiotic only if the team caring for you agrees. Probiotics are live bacteria or yeast, and the evidence that they are safe for most people comes from studies of people who were not significantly immunosuppressed, so on tacrolimus let your specialist team's advice decide.
Evidence: Supported by human study data.
Probiotic timing with antibiotics
Good to know Does Probiotics interact with Amoxicillin?
Probiotics and amoxicillin are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your amoxicillin dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics, particularly Saccharomyces boulardii, should be checked with your doctor first.
Evidence: Supported by human study data.
Good to know Does Probiotics interact with Ciprofloxacin?
Probiotics and ciprofloxacin are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your ciprofloxacin dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics, particularly Saccharomyces boulardii, should be checked with your doctor first.
Evidence: Supported by human study data.
Good to know Does Probiotics interact with Clarithromycin?
Probiotics and clarithromycin are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your clarithromycin dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics, particularly Saccharomyces boulardii, should be checked with your doctor first.
Evidence: Supported by human study data.
Good to know Does Probiotics interact with Co-trimoxazole?
Probiotics and co-trimoxazole are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your co-trimoxazole dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics, particularly Saccharomyces boulardii, should be checked with your doctor first.
Evidence: Supported by human study data.
Good to know Does Probiotics interact with Doxycycline?
Probiotics and doxycycline are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your doxycycline dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics, particularly Saccharomyces boulardii, should be checked with your doctor first.
Evidence: Supported by human study data.
Good to know Does Probiotics interact with Erythromycin?
Probiotics and erythromycin are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your erythromycin dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics, particularly Saccharomyces boulardii, should be checked with your doctor first.
Evidence: Supported by human study data.
Good to know Does Probiotics interact with Metronidazole?
Probiotics and metronidazole are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your metronidazole dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics, particularly Saccharomyces boulardii, should be checked with your doctor first.
Evidence: Supported by human study data.
Good to know Does Probiotics interact with Minocycline?
Probiotics and minocycline are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your minocycline dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics should be checked with your doctor first.
Evidence: Supported by human study data.
Good to know Does Probiotics interact with Nitrofurantoin?
Probiotics and nitrofurantoin are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your nitrofurantoin dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics, particularly Saccharomyces boulardii, should be checked with your doctor first.
Evidence: Supported by human study data.
Good to know Does Probiotics interact with Trimethoprim?
Probiotics and trimethoprim are fine to use together, and probiotics may lower the chance of antibiotic-related diarrhoea. If you take a bacterial probiotic (most Lactobacillus or Bifidobacterium products), space it about two hours away from your trimethoprim dose so the antibiotic does not reduce the live bacteria. Saccharomyces boulardii is a yeast rather than a bacterium, so the antibiotic does not affect it and it can be taken at the same time. The main exception is if your immune system is seriously weakened or you are critically ill in hospital, when probiotics, particularly Saccharomyces boulardii, should be checked with your doctor first.
Evidence: Supported by human study data.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.
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How the checker decides
Every result has a source
Each pair we have assessed is cited to a published study (PMID) or the British National Formulary, so you can read the source yourself.
Four kinds of answer
Severe, caution, no known interaction, and not yet assessed. A pair we have not assessed is never shown as clear.
- Severe
- Caution
- No known interaction
- Not yet assessed
Nothing in our data is not a clearance
When nothing in our data records a problem with a pair, the result says no known interaction at typical doses, which is not a clearance: your pharmacist or GP can check the pair against your full medical history.
A full supplement review, built around you, not a generic stack.
The free checker answers one interaction question at a time. A Distil report reviews the bigger picture: your goals, diet, medications, current supplements and any blood results you provide, then shows what appears worth keeping, changing, adding or leaving out.
- what your diet already covers, so you are not adding a capsule for something food is already handling
- which evidence-graded compounds are worth considering for your goals, and which were considered but left out
- what to keep, change or stop from what you already take, plus the order to introduce anything new
- how your medications and complete supplement stack fit together, with daily timing and a clear point for reassessment
The interaction check is one section of the full report. You also get the reasoning behind each recommendation and the evidence references used.
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