does garlic kill probiotics

Does Garlic Kill Probiotics? (how long it takes to kill bacteria)

For this article, I have overviewed all the scientific material I could access to find out the relationship between garlic and probiotics and if you can consume the two together or not.

Before everything, here is a hint that may lead you to your answer, –  Garlic-probiotic fusion isn’t prohibited completely, and the Turkish garlic and yogurt sauce is one example.

In this article, you will find out how garlic affects probiotics and gut health and how you can prevent your probiotic dose from getting lost because of it.

Key Highlights
  • The bactericidal compounds in garlic may kill some probiotics like the Bifidobacterium species while others, like the Lactobacillus species, mostly escape them.
  • Garlic’s antimicrobial activity affects probiotic bacteria, but it also has prebiotic components like fiber that nourish the gut microbiome.
  • Garlic may prevent gut dysbiosis if consumed in moderation because it helps get rid of harmful gut bacteria and feeds the beneficial ones.

Does Garlic Affect Probiotics? Here’s How!

Yes, multiple in-vitro (in an artificial system) studies suggest that garlic’s antimicrobial activity affects probiotic bacteria.

But the response depends on the quantity and concentration of garlic usage and the resistance potential of the species. 


Where on the one hand, the probiotic Bifidobacterium species is more susceptible to garlic extract. On the other, studies suggest that it is ineffective against the probiotic Lactobacillus species when used in quantities as low as 10 µL; however, it may kill them at a high volume of 100 µL. 

Similarly, fresh garlic juice has a greater antimicrobial potential than ground garlic.

Apart from this, studies also demonstrated that garlic fructan might act as an effective prebiotic and selectively promote the proliferation of beneficial gut bacteria such as L. casei or Bifidobacterium species.

But for this purpose, garlic should be used below the concentration at which it shows sufficient antimicrobial activity.

Now read further to know the scientific justification behind this script.

How Does Garlic Kill Bacteria?

Garlic has certain antimicrobial compounds that kill bacteria.

You can further understand this through research that was designed to evaluate the antimicrobial activity of garlic clove extract against the probiotic bacteria Bifidobacterium.

The result of this study elucidated that crushing garlic cloves releases ‘allicin’, which may reduce the viability of Bifidobacterium species (B. lactis, B. bifidum, and B. longum).


Here, allicin is a highly volatile antimicrobial compound that also gives garlic its characteristic smell. This compound targets the Bifidobacterium cells by damaging the cell membrane (cell’s outer covering) and the nucleic acids (DNA/RNA) inside the cell.

Besides this, among the Bifidobacterium species, B. longum was found to be most susceptible to garlic, whereas B. lactis was the most resistant.

How Long Does It Take For Garlic To Kill Bacteria?

The antimicrobial compounds in garlic start killing bacteria as soon as they come in contact, but it may take around 24 hours to up to two weeks to clear up infections.

When garlic extract is applied to a bacterial lawn in labs, you can visualize clear zones within 24 hours.

Likewise, an article in midwifery today states that a garlic clove may clear up vaginal infections in a single night or, at most, two days. 

Nevertheless, most studies usually evaluate the potential of a 2–3-week garlic course for treating infections.

Can You Take Garlic And Probiotics Together?

Yes, but not all of them, and other terms and conditions also apply if you want to consume this combination.  

It is not like garlic and probiotics can’t exist together; pickled garlic is the biggest example to prove this.

However, I just mentioned above that garlic contains ‘allicin,’ and too much of it may wipe out the probiotic strains. So, as a key, Lactobacillus probiotics and a low concentration and quantity of garlic might work well together.

And Gladly, according to, the research couldn’t conclude any interactions between garlic and probiotic formulations as well.

Even so, this doesn’t completely rule out the possibility, so it is better to consult a doctor. Despite that, here are some paths you can take around your probiotic and garlic intake.

You Might Get To Relish The Two Together If You Pair Them Wisely

A recent 2022 in-vitro research checked the effectiveness of pairing different concentrations of garlic extract that ranged between 3.13% to 75% with 5 different Lactobacillus strains.

Surprisingly, the results revealed that 12.5% garlic extract could work synergistically with probiotic strains belonging to L. plantarum and Lactobacillus paracasei species to kill Salmonella species.

The reason behind this is that although the antimicrobial activity of garlic is effective against the pathogenic Salmonella strains, it does not hinder the survival of the Lactobacillus species.

Not All But Some Of Your Favorite Probiotics Might Last The Garlic Attack

In 2019, researchers checked the survival of some selected probiotic strains in the presence of ground garlic solution or fresh garlic juice.

The chosen bacteria included two yogurt starter cultures, namely Lactobacillus bulgaricus and Streptococcus thermophilus, and three commercial probiotic strains belonging to the L. acidophilus, L. rhamnosus, and Bifidobacterium longum species.

At the concentrations used in the study, B. longum was found to be the most susceptible, while L. acidophilus was not inhibited at all.

To simplify the results for you, here is the susceptibility trend from more to less for the studied strains:

B. longum> S. thermophilus> L. rhamnosus> L. bulgaricus> L. acidophilus

Is Garlic Bad For Gut Bacteria?

No, garlic is not bad for gut bacteria. Instead, it may prevent gut dysbiosis if you consume it in moderation.  For a fact, garlic is a great source of fiber and organosulfur components. This stuff imparts prebiotic and anti-bacterial properties to the garlic; therefore, it not only nourishes the gut commensals but also helps get rid of harmful bacteria.

Here is how garlic may help the gut and its inhabitants:

Garlic Helps Get Rid Of The Harmful Gut Bacteria

Garlic has abundant organo-sulfur compounds such as allicin and ajoene that have an anti-bacterial action and are now being pursued as potential candidates for novel antibiotics.

For instance, a 2021 review compiled evidence that suggested that these compounds can kill bacteria, prevent their biofilm formation, repel their toxins, and interrupt the transfer of multi-drug resistant (MDR) genes between bacteria.

Furthermore, multiple studies report that garlic is effective against so many pathogenic bacteria such as E. coli, Clostridium difficile, H. Pylori, etc. 

And that is not all; it also wards off protozoans such as Giardia and Cryptosporidium.

Therefore, by consuming garlic, you may prevent the nasty gastrointestinal symptoms associated with these pathogens, such as Diarrhea, vomiting, stomach cramps, bloating, etc.

Garlic Feeds The Beneficial Gut Bacteria

Garlic is a rich source of fructans, a soluble fiber that contains inulin and oligo-fructans/fructooligosaccharides (FOS).

Both these fructan components diversify the gut microbiome, which ultimately prevents diseases and promotes gut health.

For instance, a 2020 meta-analysis compiled evidence from human studies to show that inulin helps the Bifidobacterium and Lactobacillus species thrive in the gut but decreases the relative abundance of Bacteroides species (an opportunistic pathogen).

Relative to this, a 2019 study found that the lowest garlic concentration of 4% can enhance the growth of L. acidophilus because of its high FOS content.

Furthermore, a clinical trial found that purified garlic fructan serves as a carbon source for the Bifidobacterium specie in the gut and increases its number.

Here you can see how the fructan content of garlic is helping to stabilize the gut microbiome.


Does Garlic Kill Lactobacillus?

Yes, but it basically depends on the Lactobacillus strain and the strength of the garlic that you are using. As mentioned above as well, research shows that more than 100µl of garlic extract may have greater antimicrobial activity against Lactobacillus species. On top of that, garlic is more likely to kill L. rhamnosus and L. bulgaricus species instead of L. acidophilus specie.

Does Allicin Kill Good Bacteria?

Yes, as I explained in the above sections, allicin may kill good bacteria such as Bifidobacterium.

Does Raw Garlic Kill Probiotics?

Yes, raw garlic basically releases allicin when it is crushed, which may kill probiotics. But how this extract is derived from raw garlic also determines its anti-probiotic potential. This can be justified by student research that concluded that fresh garlic clove extract has a more potent anti-bifidobacterial activity as compared to garlic paste extract. 

Does Eating Garlic Kill Probiotics?

Yes, but it depends on the degree of resistance of each probiotic bacteria and how much garlic you consume.

Does Garlic Kill H Pylori?

Yes, garlic may kill H. pylori. This claim can be supported by the outcome of a clinical trial on 15 patients in which routine administration of garlic led to significant improvement in their H. Pylori infection.

Wrap-up – Will Garlic Kill Good Bacteria?

Garlic has antimicrobial compounds that can threaten the survival of probiotics as well. Nonetheless, the survival of the probiotics is greatly dependent on their resistance capacity. For instance, according to a study I referenced before, L. acidophilus outlived the pathogenic Salmonella species when garlic was applied to them.

What you can do to attain optimal probiotic benefits is opt for Lactobacillus species and reduce the consumption of garlic while you are at it. However, taking Bifidobacterium probiotics might not be a good idea because garlic greatly compromises its efficacy.

Ending with the note that you should always consult your healthcare provider for professional advice as user experience may not always coincide 100% with the scientific findings.

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