Probiotic Side Effects

probiotic side effects

You might have heard or have experienced the benefits of probiotics, however, there is “too much of a good thing” when taking probiotics. In this case, this would include probiotic side effects. 

Your body is filled with microorganisms, both good and bad. Probiotics are live, beneficial bacteria and yeasts that not only improve your gut health, but can also offer a number of other health benefits. 

If you have an infection, more bad bacteria enter your system, causing an imbalance. Good bacteria help to replace the bad and restore balance. Probiotic supplements are one way of adding beneficial bacteria to your body.

In this article, we discuss what to expect from probiotics and ways to manage side effects if you experience any.

What Are Probiotics?

Probiotics are living microorganisms that have many health advantages. They carry out functions that aid in the proper functioning of the body. This is what’s called “symbiosis” – a symbiotic relationship as we benefit from their presence and they benefit from ours.

Probiotics can be found in supplements and fermented foods such as yogurt, kimchi, and sauerkraut. The common type of probiotics are bacteria belonging to the genus Bifidobacterium, Lactobacillus, as well as yeast from Saccharomyces boulardii

Probiotics are frequently used to improve gut health. These friendly microbes slow the growth of disease-causing bacteria. They can also enhance nutrient absorption and aid in the digestion of food. 

Probiotics may also help people who have allergies, urinary tract issues, and skin conditions.

Are Probiotics Harmful?

As already mentioned, there are good and bad bacteria in your body. Therefore, consuming probiotic foods or supplements is generally considered safe. However, here are some reasons they can be harmful:

  • It has been noted that some probiotic products can contain bacteria other than those mentioned on the label. Unidentified bacteria in products can pose a health concern
  • It is possible for probiotics to cause infection, produce harmful substances, and transfer antibiotic resistant genes to other microorganisms in the gastrointestinal tract
  • Individuals with impaired immune systems and severe illness have a greater risk of probiotic side effects
  • When considering probiotics for those who are high-risk, such as premature babies or critically ill individuals, the possible side effects of probiotics should be carefully evaluated against the benefits

Bear in mind that taking too many probiotics can also cause uncomfortable digestive symptoms. Consult with your healthcare provider before taking a new supplement. If recommendations are made, make sure to follow the dosage instructions according to the supplement label.

Probiotic Benefits

Probiotics are continuously being studied to determine when they should be consumed and how they can be most beneficial. The following are some benefits of probiotics:

  • Manages ulcerative colitis
  • Decreases diarrhea
  • Assists in the treatment of urinary tract infections
  • Prevents Crohn’s disease from relapsing
  • Helps ease IBS symptoms
  • Decreases the symptoms of allergies and asthma
  • Treats and prevents yeast infections
  • Minimizes inflammation

Possible Probiotic Side Effects

Taking probiotics every day has a number of advantages, but it can also have negative side effects. The following are possible side effects of probiotics:


Some foods rich in probiotics and protein, such as yogurt, sauerkraut, and kimchi, have amines. Amines can be produced during the fermentation process of some food sources. Histamine, tyramine, and tryptamine are the most prevalent amines identified in foods rich in probiotics.

what are the side effects of probiotics

These amines can stimulate the central nervous system, increase or decrease blood flow, and cause headaches in individuals who are sensitive to the substance. According to several studies, low-histamine diets alleviated headaches in 75% of individuals. 

However, some research revealed that dietary amines had no effect on headaches and additional studies need to be done to determine whether amines can cause headaches in some individuals.

Keeping a food journal that includes any headache symptoms you may be experiencing will help you determine whether fermented foods are a concern for you. If foods that contain probiotics aggravate your symptoms, a probiotic supplement may be a better alternative.

Skin Problems

It is rare, but possible for probiotics to cause skin rashes or itching in some cases. This can be temporary, but uncomfortable. Here’s what to do if you develop any skin problems:

  • Stop using the probiotic
  • Check the product labeling for allergens 
  • Consult a qualified healthcare professional
  • Try different probiotic supplements

Risk Of Infection

Probiotics are generally safe for the majority of individuals, however, they may not be the ideal choice for everyone. In rare situations, bacteria or yeasts included in probiotics can enter your circulation and cause illnesses in vulnerable individuals. 

Perscription probiotics tend to contain more targeted strains and are less likely to cause severe interactions.

Those with impaired immune systems, under long-term hospitalizations, or recovering from recent surgery are at the most risk of infection from probiotics.

Nevertheless, the risk of infection is quite low. Approximately one in a million individuals who take probiotics that contain Lactobacilli bacteria become infected. The danger of infection is significantly lower for probiotics that are yeast-based, with just around one in every 5.6 million users becoming affected.

If an infection does occur, taking probiotics with antibiotic or antifungal medication usually works well. Unfortunately, deaths have occurred in a few instances. According to some studies, individuals with severe acute pancreatitis should avoid taking probiotics since they may raise their risk of death.

Small Intestine Bacterial Growth (SIBO)

Bacteria in the small and large intestines are distinct. Small intestinal bacterial overgrowth (SIBO) happens when bacteria from the large intestine colonize the small intestine. 

The large intestine is mostly populated by anaerobic bacteria, which do not require oxygen to survive. Instead, they live on digesting indigestible carbohydrates from plant-based food as they move through the gut.

SIBO symptoms include gas, bloating, and diarrhea, which are similar to IBS symptoms. It can also result in brain fog and short-term memory issues. SIBO doesn’t affect everyone who has IBS, although it is more common in those who have the condition.

It’s also common in older women. When individuals stopped taking probiotics and began taking antibiotics, their symptoms improved. Anyone experiencing SIBO symptoms should seek advice from a qualified healthcare professional.

Uncomfortable Digestive Symptoms

While the majority of people don’t experience side effects, the most typically reported response to probiotic supplements is an increase in gas and bloating for a short period of time. Those who take probiotics made from yeast may experience constipation and increased thirst. It’s unknown why some individuals experience these side effects, but they usually go away after a few weeks of continuous use.

It is typically recommended to start with a low dosage of probiotics and gradually increase to the full dosage over a few weeks to lessen the chance of negative side effects. This can help your body adjust. 

If the bloating, gas, or other side effects persist for more than a few weeks, stop using the probiotic and speak to a qualified healthcare professional.

Antibiotic Resistance

Antibiotic-resistant genes are only found in a small percentage of probiotic bacteria. They can transmit these genes on to other bacteria strains, including the pathogenic types that cause illnesses.

Manufacturers test commercial probiotic strains for the presence of antibiotic resistance on a regular basis. To avoid the risk of ingesting antibiotic-resistant bacteria, only buy probiotics from reliable companies.


side effects of probiotics

Individuals who suffer from allergies or food intolerance should carefully read the labels of probiotic supplements because they may contain ingredients to which they are allergic or intolerant.

While some studies show that most individuals with lactose intolerance can handle up to 400 mg of lactose in medicines or supplements, there were reported cases of probiotics causing severe side effects. 

Since a small proportion of individuals with lactose sensitivity may feel uncomfortable gas and bloating while ingesting probiotics that contain lactose, lactose-free products may be preferable.

Increased Histamine Levels

Some bacterial strains included in probiotic supplements can produce histamines in your digestive tract. Histamine is a substance that your immune system generally produces when it recognizes a threat.

Your arteries dilate to bring more blood to the affected area when histamine levels rise. The vessels become even more penetrable, allowing immune cells to enter the relevant tissue and attack any invaders. 

This process causes redness and swelling in the affected area, as well as allergic response symptoms such as itching, watery eyes, a runny nose, and difficulty breathing.

Histamine is made in the digestive tract and is normally destroyed by an enzyme called diamine oxidase (DAO). This enzyme prevents histamine levels from rising too much to induce symptoms. 

However, some individuals have a histamine intolerance called “food histaminosis” or “enteral histaminosis” and don’t make enough DAO. They also have difficulty adequately breaking down histamine in their bodies.

Extra histamine is subsequently transported through the intestinal lining into the bloodstream, resulting in symptoms similar to those of an allergic reaction. 

Anyone suffering from histamine sensitivity should avoid supplements high in histamine. Streptococcus thermophilus, Lactobacillus buchneri, Lactobacillus helveticus, and Lactobacillus hilgardii are some probiotic strains that produce histamine.

Duration Of The Side Effects

The duration of side effects differs from person to person, but they should only last a few days after you start on a new supplement. 

If the symptoms persist for more than a few days, are severe, or you suspect an underlying health problem, discontinue the use of the probiotic and speak to a qualified healthcare professional.

Keep in mind that probiotics hardly ever have any negative side effects. As a result, rather than assuming that any significant or alarming symptoms are due to the probiotics, consult with a qualified healthcare professional.

Final Thoughts

Probiotics might create unpleasant side effects such as gas, bloating, and headaches, but if you stick with it, the side effects should go away in about two weeks. 

You’ll start to have more energy, improved immune function, less bloating, and regular bowel movements once your gut has adjusted to the probiotics. If you don't feel better after a few weeks, there could be an underlying issue going on that warrants a visit to a qualified healthcare professional.

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**This blog is for information and education purposes only. This information is not intended to substitute professional medical advice, diagnosis, or treatment. Please consult with your physician or another qualified health provider with any questions in regards to a medical condition. A qualified healthcare professional can best assist you in deciding whether a dietary supplement is suitable based on your individual needs.