Everything you need to know about garlic & SIBO

Judging by posts in the SIBO SOS® Facebook Community, many of us who struggle with Small Intestine Bacterial Overgrowth  are VERY confused about garlic!

Here are some screenshots of posts we’ve had in the group:

Let me start by saying – I totally understand the confusion! I used to be confused myself.

You may have heard that you shouldn’t eat garlic if you have SIBO… but that garlic is also a popular treatment…. How can that be? 

But it’s actually simple once someone explains it to you. I was lucky enough to have Dr. Allison Siebecker explain the difference to me, and today I want to pass that knowledge on to you!

Is Garlic a “Forbidden Food” For SIBO Patients?

This is where all the confusion begins! 

Garlic is a high-FODMAP food. FODMAP stands for fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. These are short chain carbohydrates and for people with issues like SIBO or IBS (irritable bowel syndrome), foods that are high in FODMAPs can increase symptoms like bloating and discomfort. 

Many diets for SIBO and IBS recommend limiting high-FODMAP foods and sticking to a low-FODMAP diet. 

But defining what foods are “high” and “low” in FODMAPs is a little tricky. There’s no universal standard for high and low, and quantity matters a lot, as well. Even a food that is very high in FODMAPs might be well-tolerated by people with IBS and SIBO in smaller quantities. 

To make it even MORE confusing, not all people with SIBO or IBS react to all high-FODMAP foods. Some people might only struggle with oligosaccharides and be fine with polyols, for example. And some people might be able to tolerate one food that is high in monosaccharides but not another.

That means that there is no such thing as forbidden foods for SIBO and IBS. The best diets for SIBO and IBS are “frameworks” for finding the foods that work for you – not black and white guidelines. 

The only way to know what foods you can and can’t tolerate is to test them! (To learn more about this, I recommend Dr. Siebecker’s Diet Masterclass).

Garlic is a high-FODMAP food that contains fructo-oligosaccharides that some people with SIBO don’t tolerate – but for others, it is just fine (or maybe only tolerated in small quantities). 

What About Garlic Infused Foods?

Some people who develop symptoms after eating whole garlic (like a clove of garlic in tomato sauce) are able to tolerate garlic infused foods (like olive oil). 

That’s simply because the short chain carbohydrates that can cause a problem are in the fiber of the garlic. 

That being said, some people say that even low-FODMAP garlic infused items cause symptoms for them.

But remember: for all foods, the “dose makes the poison” when it comes to FODMAPs. You might be fine with a hint of garlic but can’t handle a lot. Or perhaps you’re very sensitive to garlic and have to temporarily avoid it altogether. 

Or maybe you don’t react to garlic at all… but find you can’t tolerate apples or oatmeal or some other food. We’re all unique and there’s no one-size-fits-all protocol.

But one last thing: just because a food is high-FODMAP or causes symptoms for you doesn’t mean that the food is bad, unhealthy, or has to be avoided for life.

Comparison isn’t helpful in SIBO – just because one person can tolerate garlic and you can’t doesn’t mean you’ll never eat Italian again or are doing something wrong! 

Using Garlic To Treat SIBO

Garlic isn’t just a sometimes-problematic food… it’s also one of the most effective natural treatment options for SIBO.

But if many people with SIBO don’t tolerate garlic, how can that be? 

According to Dr. Siebecker, garlic is one of the 4 main herbs used to treat SIBO – but it’s not just regular garlic cloves you can buy at the grocery store. 

Instead, it’s an extract of garlic called allicin.

“The four main herbs that we use typically to treat SIBO are berberine containing herbs, which are things like goldenseal root, Oregon grape, barberry Coptis. Neem is a traditional ayurvedic and a microbial. We use oregano, like the kitchen herb spice, oregano oil. And then lastly is an extract that comes from garlic called allicin, like my name but it’s spelled different. 

And in that one we like to use stabilized allicin extract because garlic is a very fermentable food and triggers a lot of people’s SIBO symptoms. We don’t want to use whole garlic per se like the actual clove taking it down, unless somebody did tolerate that, but it’s pretty common for SIBO people not to. And we don’t want to use like garlic crushed or garlic oil. We prefer the antibacterial extract allicin that’s been extracted out.”

Even if you can’t tolerate garlic whatsoever, you will likely be able to tolerate allicin extract as part of a SIBO treatment because it doesn’t contain the problematic fructo-oligosaccharides. 

Why Garlic Is A Key Player In Treating SIBO

There are three main types of SIBO: hydrogen dominant, methane dominant, and hydrogen sulfide.

(Although as research continues to advance, more types and more specifications within each type are likely to be discovered!)

According to Dr. Siebecker, “The special thing about allicin is that this is what treats the methane, methanogenic archaea (which, for ease, we’ll just say bacteria). They are tough to kill. And they need different antimicrobials to kill them. And the extract from garlic does it, allicin. It works against them. We see it clinically. We see it with our before and after breath tests. It’s for real.”

If you have methane, garlic is a must-have for herbal antibiotic treatments. 

The Garlic Dr. Siebecker Recommends 

If you’re considering taking garlic as part of an herbal protocol for SIBO, here’s what Dr. Siebecker has shared with me in the past:

“Berberine and Allimed is my go-to combination. I think of berberine kind of like Rifaximin, and Allimed like the neomycin or metronidazole, because this is what works on the methane, this is what works on the hydrogen—and you need to do them both.”

Here’s why a two-part treatment is so important:

“The reason you need to do them both is because methane archaea turn hydrogen into methane. So there are already bacteria making hydrogen there, and then there are other bacteria that are turning that hydrogen into methane. You have both there, so you need to address them both.”

And what about choosing the right allicin supplement?

“My go-to is Allimed. And we use the “-med” because it just gives the strongest potency in the least amount of pills. And the dose on this is six a day. And usually, when you’re taking a bunch of pills, we split that into three doses. You can do it as two, three times a day, or you can do it as three, two times a day.”

Help! I’ve Already Tried Allimed (Without Results)

Remember that SIBO is a tricky condition to treat – and typically requires trial and error (if you’re one of the lucky ones who’s very first treatment eradicate SIBO – good for you!).

Dr. Siebecker recommend trying Allimed paired with another herb – if you tried Allimed and berberine, for instance, try Allimed and neem next.

How often can you keep repeating this? 

“Keep going until we don’t think it’s working anymore or we see on the test it’s not working anymore,” said Dr. Siebecker. 

My Allimed Experience

As a person with methane SIBO, I’ve used Allimed several times. 

I have a very fond feeling toward it, as it definitely made a huge improvement in my symptoms!

My pro tip? Keep it in the fridge or freezer. It does have a noticeable “garlic-y” smell and keeping it frozen helps reduce the odor!

Want to try it yourself?

I know how expensive trying different treatments can be – so I’m excited to be able to share a special discount with you today!

Use this link sibosos.com/allimax to get 20% off AlliMax.

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36 thoughts on “Everything you need to know about garlic & SIBO”

  1. Hi. Just for clarification, do we take 6 capsules of Allimed (Allicin) 180mg, per day? So a total of 1080mg??

    1. SIBO SOS® Support

      Hi Shelina,
      We are legally prohibited from making any direct recommendation on one’s medical condition or from making any direct referrals. You may check Dr. Allison Siebecker’s website. She has a slew of information on there, including a dedicated page about Herbal Antibiotics.

  2. Aiming to treat methane-do SIBO but on a very low budget – I can only invest in one product at the moment, so I wondered if using Allicin on it’s own would improve my gut health or does it have to be combined with herbals to make a difference?
    thanks for all the great work and info you share.

    1. Cyndi Athmanathan

      Be sure to use Dr. Siebecker’s professional discount so you save a little each time you do invest in a product. visit sibosos.com/shop and click on FullScript which offers AlliMax and Allimax Pro.

  3. Does Kyolic Aged Garlic Extract contain allicin? I take it for heart related issues (2 g/day). I have methane sibo.


  4. Whitney Wood Bailey

    Hi! I have hydrogen dominant SIBO and am taking oil or oregano, neem, and berberine. Can I add Allimed to the mix? Does it help with STUBBORN cases of hydrogen dominant SIBO?

    1. Hi Whitney,

      I’m sorry to hear you have STUBBORN hydrogen… that’s a quality heard more with methane, so that’s interesting!

      If you can find the time, Dr. Siebecker will be back temporarily from her hiatus to do a webinar with us. I think that would be the perfect opportunity to ask her if she feels adding allicin might help budge that stubborn hydrogen. Register for Dr. Siebecker’s webinar here… we’ll send you the Zoom link via email!

      I hope you can carve out the time to join us! Looking forward to maybe having you 🙂


      1. Dear Clarissa,

        I have stubburn constipation :(,and my health practicioner recommended me Atrantil (it made of : horse chestnut extract aescins, peppermint leaf, and quebracho) that I started yesterday.
        Reading your articles I consider start take Allimed next to Atrantil (killing methan producer bugs in my gut)
        What do You think, can be good idea allicin to complete Atrantil (can I take them together?
        Thanks for you answer,
        Best regards,

        1. SIBO SOS® Support

          Hi Zsofia,

          Of course we can’t give medical advice, so you’ll have to ask your practitioner. But I do know Dr. Siebecker likes to combine Atrantil with either berberine, neem or oregano for methane. That’s not to say she hasn’t done Atrantil next to Allimed… I’m just stating that I don’t know if she does that combo in particular.

          I know she’s also recommended Allimed with berberine, neem or oregano too. But if your practitioner already has you on Atrantil, then I don’t recommend digressing from her recommendation. Just ask him/her what he thinks about adding either berberine/neem/oregano to the mix 🙂

          I hope that helps! Good luck!


    1. Hi Jared,
      That is so very interesting! I haven’t heard of that personally. But if you’re available over this weekend, Shivan will be hosting a lecture with Dr. Allison Siebecker. And there’s going to be a quick Q&A at the end so you can ask Dr. A herself!

      We’d love to have you. I’ll leave the registration link below. We’ll send you the zoom link as we get closer to live event:
      Webinar Signup

    2. Hi, my grandma has just been told that he has more than likley got SIBO and we’re awaiting the breath test results. We have been told to start on Allitrin but she has been feeling nausea after taking it. Is this a common side affect?
      Thanks in advance!

      1. SIBO SOS® Support

        Hi Avnish,

        Is that a typo? Did you mean to say allicin (which is the garlic extract) or did you mean to say Allitron (which is more of a fungicide)?

      1. SIBO SOS® Support

        Hi Fabio,
        Universally speaking, you could react to anything in any possible way…. and that’s also true for allicin! I haven’t had the chance to Dr. Siebecker how common excessive gas is from taking allicin, but it certainly could happen!
        Allicin is definitely a sulfur donor. So if you have a problem with sulfates, you might want to ask your practitioner if allicin is a good match for you.
        Good luck!

  5. I have Allimax pro 450mg capsules. How many of those should I take per day? On the container it says just one. Thank you.

    1. Hi Scott,

      I don’t have a direct answer to that… but I know that in Dr. Allison Siebecker’s Treatment & Prevention Masterclass, she does mention that she tends to use 2700 mg. a day split into two or three doses – usually three. That’s about six Allimeds a day. I haven’t recently checked on the less potent Allimax though to know for sure how much that translates to.

      That’s no advice! Do check with your practitioner please? I know you must be tired of hearing that, but it’s critical that you do!!

  6. So I gather that people with hydrogen sulfide SIBO, like me, need not bother using Allimed. It sounds like this supplement is only appropriate for those with methane SIBO. The practitioner who diagnosed me with HS SIBO had me on a Allimed and berberine. I noticed no improvement in any of my symptoms. I also did a round of ADP and Néem. That didn’t help either. What made a huge difference with one symptom (mental fatigue) was Rifaximin.

  7. Hi, Shivan. I just want to THANK you and your staff for sharing so much wonderful information. My head is spinning with all the info but I am doing my best. One thing that hasn’t been discussed, I don’t think, is taking all these herbs, supplements, etc. when we are on quite a number of prescription pills for other things. I have some major heart issues and much of my medicine must not have “other things” taken 2 hrs before or 2 hrs after the meds. Thus I have a small window for taking a lot of other helpful things. When I try to discuss this with a doctor, unfortunately they think I’m trying to tell they their job or that I’m just crazy. I have checked and my insurance does not list ANY naturopaths or alternative/complimentary doctors. If it were not for you and the information you so graciously post on line it would be impossible for me to get any kind of help at all. I just turned 80 and have had stomach issues since in my 20s (fortunately not nearly as badly as many people), but am excited about the prospect of getting better and better. I am being very dedicated about this as much as I am able and just want to say very sincerely: THANK YOU!

    1. Hi Judy, thanks so much for reaching out with your kind words! I’m sorry to hear you’re struggling and I know it is very frustrating to have doctors give you “that look!” You might see if your insurance covers any DOs (doctor of Osteopathic medicine) or any MDs who specialize in internal medicine as they might have more knowledge about supplementing. Try talking with your pharmacist, as well – he might have some good suggestions for you.

  8. Thank you for your help Shivan. I didn’t realise garlic and Berberine could be used together.
    I tried ADP but couldn’t take it but Berberine I’m fine with.

  9. hi. i considered allimed but it contains maltodextrine which is corn and i am glutn intolerant cross reactive to all grains especially corn. ur thoughts plz. thx

    1. Hi Merrianne! We reached out to the team at Allimed and they said that to their knowledge, the maltodextrin hasn’t caused issues – but they also let us know that the liquid version is maltodextrin free and 8 drops is equivalent to one capsule. Hope that helps!

        1. Hi Charley, Dr. Allison Siebecker recommends 900 mg. a day 3x a day in combination with your preferred antimicrobial for methane SIBO. Take the dose to your practitioner please and see what they say! Hope that helped though 🙂

  10. Hi!! I had the pleasure of working with Dr. Melanie Keller via Skype a few years back. She recommended this protocol. I couldn’t tolerate that high of doses, but I did really well on smaller doses of allicin. I self-created and got major improvement. Because I live in New York State there are laws in regards to doing these home testing lists and that was an unfortunate hindrance because it can be a lot of jumping through hoops to get the proper testing in New York state, unless you are working with a practitioner that is easy to travel to. Hopefully, the laws will or maybe already have changed!! I also was dealing with histamine issues, salicylate issues and oxylate issues and lectin issues. Everything in moderation seems to help, and low FODMAP helps too!! Omega3’s and mi erals (mostly liquid magnesium) were, and still are, life-savers for me. Just Thrive spore based probiotics helped too!

  11. I was put on the Allimed (allicin) and Berberine and iberogast protocal 3 years ago for about 6 months…it helped somewhat with gas, digestion and motility, settling my gut, but it did not improve my ability to eat anything but very low FODMAP foods. I was diagnosed with high methane SIBO. I also learned I’m actually allergic to garlic. I developed very problematic acne, (I’m 67 yr.s old) and once the allimed was discontinued, it completely cleared up. It was then I realized that all my break-out skin issues from the time I was a teenager was exasperated by garlic, and probably onions as well. Garlic infused oil has the same effect. There are likely more foods, but those two in particular were very easy to discover. Since then I have been taking Atrantil (has proven helpful) and continued with Iberogast. I have also found the Fast Tract Diet helpful in allowing me a few more food choices, but I am still very limited, and my motility is very, very slow, even when I take magnesium (CALM) at night. Question…1. is there an alternative to allimed that has proven to be effective? Question 2. I’ve learned that short chain fatty acids are extremely important for the health of the gut microbiome…..foods I can’t digest. Is there a way to bring those into my diet without producing the very painful methane symptoms? Thanks so much, Shivan, for all your time and hard work for us all. Liz

  12. Can a person successfully use the Allimed liquid in place of the capsules and if so, what would the dosage be? Taking too many herbal pills to treat my SIBO has made me really sick to my stomach in the past. Thanks.

    1. Hi Margot – the team at Allimed let us know that 8 drops of the liquid is equivalent to 1 capsule and they can be used interchangeably!

          1. Cyndi Athmanathan

            We just discussed this during our Q&A session which is included in the SIBO Recovery Roadmap course along with the treatment chart that would give you several options for you to try or discuss with your doctor. Berberine and Allimed alone may not get the results you want – to get your life back. Your tolerance and breath test results are one of many factors. For methane SIBO what has been found effective is Allimed or AlliMax Pro, it’s six a day dose. And assumably you’ve done six a day of Atrantil with a treatment round for four to six weeks to get the methane down. As you know SIBO is not a one and done the combination is important.

  13. As usual, you have helped greatly with the confusion about garlic .
    Thanks again for all you do and for caring about this many leveled
    Issue that destroys our health.

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