Can Spicy Food Kill Good Bacteria?

For people who use spices all the time and can’t imagine cooking without them, learning about a great new benefit of adding them to food is always interesting. Many people should have heard about the benefits of spices, like how they kill bacteria, but the real question here is, can spicy food kill good bacteria?

Yes, spicy foods can kill good bacteria. Researchers, nutritionists, and biologists have studied the antimicrobial and antifungal properties of spices and found that most of them can stop certain bacteria from growing. Spicy foods have been found to kill bacteria because spices give off heat, which kills bacteria in the body.

There is little distinction between pathogens, which are harmful bacteria, and commensals, which are good bacteria. As a result, antibacterial spices may be unable to distinguish which type of bacteria they kill. Continue reading to learn about the spices and the bacteria they inhibit.

How Exactly Do Spices Kill Bacteria?

It has been suggested that the antibacterial properties of spices stem from the protective properties of certain phytochemicals. This means that using these spices can slow or stop the growth of microorganisms before they can make toxins. 

Capsaicin, piperine, allicin, and gingerol are the chemicals responsible for the inherent heat or spiciness in spices.


Capsaicin in chili peppers

Capsaicin is present in plants from the capsicum genus, mainly in chili peppers and also contained in oregano, cilantro, and cinnamon. Capsaicin has been shown to help with pain, inflammation, weight loss, and fighting germs, among other things. It gives the fruits that come from it their characteristic sour taste.

In one study, it was found that capsaicin kills streptococci (bad bacteria) by inhibiting intracellular invasion and hemolytic activity. This keeps infections from spreading to deep tissues and eliminates intracellular reservoirs. Another study found that adding capsaicin slowed the growth of Escherichia coli, a good bacteria.

Capsaicin fruits have also been shown to have a staggering amount of vitamin C, which is six times that of oranges. They help to boost the immune system and increase blood circulation.


Piperine is the main alkaloid in black pepper, which gives it its sharp flavor and spicy heat. It is found in both the outer seed and the fruit of black pepper, accounting for 4.6%–9.7% of the total mass. Piperine has medicinal, antimicrobial, and antioxidant properties in addition to its spiciness.

Black pepper extracts have been used in various studies to demonstrate bactericidal actions by altering the permeability of bacterial cell membranes. When the cell wall is altered, electrolytes and metabolites are lost. This results in the cell’s death.

Some bacteria against which black pepper was studied include Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Salmonella sp.


The main antimicrobial compound in fresh garlic is allicin, a diallyl thiosulfate. It gives garlic its distinctive odor when crushed and is produced when enzymes in damaged garlic tissue are catalyzed. It is also found in onions.

Allicin has antimicrobial activity against gram-positive and gram-negative bacteria, including antibiotic-resistant strains, as well as fungi. It reacts with thiol groups, which stops enzymes from working and inhibits DNA-gyrase, an important enzyme in prokaryotes. 


This compound is found in fresh ginger and stimulates taste receptors in the tongue. They have antioxidant, anti-inflammatory, antimicrobial, and antitumor properties when combined with shogaol and paradol.

Ginger has been shown to inhibit the growth of periodontitis-associated oral bacteria. In a study, it also demonstrated antibacterial activity against three gram negative bacteria. 

What Are Good Bacteria, Anyway?

Good bacteria, also known as commensals, are beneficial microorganisms that aid in the proper functioning of the body. They are more numerous than human cells in the body. The following are the most common strains of good or beneficial bacteria:

  • Lactobacillus
  • Bifidobacteria


Lactobacillus is naturally found in the gastrointestinal tract and the urinary tract. They benefit gut health by producing lactic acid and releasing lactase, which aids in the breakdown of lactose. This helps to prevent lactose intolerance symptoms like diarrhea. Lactic acid also ensures that the gut is unfriendly to harmful bacteria by lowering its pH. 


Bifidobacteria are naturally present in the intestines. They are commonly used to treat diarrhea, constipation, and other intestinal bowel disorders (IBDs).

They also help with digestion and absorption by breaking down food. Furthermore, these good bacteria fight off harmful bacteria that endanger the host’s health.

These, like most other commensals, are primarily found in the digestive system and are collectively referred to as gut microbes. Because it contains 70% of the immune system, the gut has been identified as the key to overall health and fitness.

Other examples include; Escherichia coli, Streptococcus thermophilus, Bacillus coagulans, and others.

Antibacterial Spices


Antibacterial spices are those that have the awesome ability to inhibit the growth of bacteria and, in theory, kill them. This ability is what gives them their name. To name a few of these spices:

  • Garlic
  • Onion 
  • Allspice 
  • Oregano
  • Thyme
  • Cinnamon
  • Tarragon
  • Cumin
  • Cloves
  • Bay leaf
  • Capsicums
  • Ginger 
  • Nutmeg 
  • Pepper (black or white), etc. 

Researchers have discovered that garlic, onion, and oregano are the best all-around bacteria killers. Thyme, cinnamon, tarragon, and cumin come in second, killing up to 80% of bacteria.

Capsicums containing spices, such as chilies, cayenne pepper, and other hot peppers, rank in the middle with approximately 75% bacteria-killing ability. White or black peppers, as well as ginger, anise seed, and celery seed, on the other hand, inhibit bacteria by 25%.

SpicesBacteria (in %)
Garlic, onion, and oregano100%
Thyme, cinnamon, tarragon, and cumin80%
Chilies, cayenne, and other hot peppers75%
Ginger, anise seed and celery seed25%

Frequently Asked Questions

Do Spices Cause Stomach Problems? 

They do not, in fact. Spices do not cause ulcers or intestinal bowel diseases, but they can aggravate them in people who already have them.

Is Spicy Food Harmful to Your Immune System?

No, not at all. Spicy foods are high in vitamin C and vitamin A, both of which are powerful antioxidants and anti-inflammatory agents.

Can Spicy Food Replace Antibiotics?

Spicy foods may have antibacterial properties, but they pale in comparison to antibiotics, which reduce bacteria on a microgram level rather than the meager milligram level of spices.

Final Thoughts

We now know that spicy food can indeed kill good bacteria, even if this has always seemed like an old wives’ tale. No longer, because the experts have taken it upon themselves to help us enjoy spices with their benefits in mind. Although it has not been accepted as a standard theory, there is solid evidence that spicy foods have antimicrobial activity.

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Bill Kalkumnerd
Bill Kalkumnerd

I am Bill, I am the Owner of HappySpicyHour, a website devoted to spicy food lovers like me. Ramen and Som-tum (Papaya Salad) are two of my favorite spicy dishes. Spicy food is more than a passion for me - it's my life! For more information about this site Click

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