Do Probiotics Have Side Effects? (With Medical Studies)

Whenever we use a new medication or supplement, we introduce a risk to our health that is an inescapable part of modern medicine. Virtually every medication has side effects of varying severity that could be a minor nuisance or utterly debilitating. The side effects we experience after taking a certain medication or supplement depend on our biological compatibility with the product. 

Sometimes, we can take medication and experience no side effects while someone else taking the same thing ends up with the worst of the listed issues. In layman's terms, side effects are a coin toss, and someone always calls the wrong side. Most products are still highly effective and reliable because their side effects only impact certain people. 

Side effects are not limited to pharmaceutical-grade medications and can occur with natural supplements in some situations. One product many have taken to using is probiotics, which have gained a significant following in modern society. While many people have begun to rely on probiotics for various benefits, there is concern about potential side effects. Despite being natural, probiotic microorganisms still have to interact with our biology and physiology, and not everyone is compatible. 

As a result, more and more people are wondering about what side effects, if any, probiotics can produce. This can be an incredibly important question for people who might be sensitive to certain issues that probiotic side effects might cause.

Do Probiotics Cause Side Effects?

The simple answer to this question is: "yes." Like many medications and supplements, probiotics are not immune to side effects. The good news is that the side effects probiotics cause are usually harmless and fade within a short time. Additionally, probiotic side effects are fairly rare and almost negligible for most people. Probiotics can cause side effects because they are living bacteria that directly interact with your biology. 

Probiotics are primarily used to treat gastrointestinal issues, which cannot alleviate the potential for incompatibility. Our gastrointestinal system is one of the most sensitive parts of human anatomy, meaning certain disruptions can yield unpleasant consequences.

Once again, the side effects incurred by probiotics are generally harmless and will seldom cause significant issues. Unfortunately, an exception to this standard makes probiotic use potentially dangerous for certain demographics. People suffering from underlying illnesses or compromised immune systems might have a more severe reaction to probiotics. 

The fact that the most serious consequences of probiotic use require the user to have a more serious condition is an excellent sign that probiotics are a relatively safe product. Nevertheless, users must be wary of these potential side effects to use them safely.

Therefore, the next question on your mind is likely about what kind of side effects probiotics might cause. Fortunately, this question is relatively easy to answer and has a scientific basis.

#1: Probiotics Can Cause Minor Gastrointestinal Distress

While probiotics are usually taken to treat symptoms of gastrointestinal distress, there can be minor complications during the initial stages. As we mentioned earlier, the gastrointestinal tract is particularly sensitive to changes. The most common side effect of probiotics, especially yeast-based organisms, is minor gastrointestinal distress that causes minor issues. The main example of this side effect is bloating and excessive gas as your body attempts to digest the bacteria. 

Ultimately, the distress caused by these side effects is minor and usually fades within a few days after the initial doses. Bloating and excess gas can occur with any probiotic since the microorganisms alter the natural balance of your gastrointestinal tract, albeit temporarily.

Yeast-based probiotics have been known to cause other gastrointestinal issues that are unpleasant but manageable. The main side effect of yeast-based probiotics is the onset of constipation and increased thirst. Once again, these side effects are rare, but this type could require you to suspend the use of the yeast-based probiotic. The big question is: why does this happen? Unfortunately, that is a question modern research has been unable to answer. There is no exact answer to why probiotics generate these side effects, and the current hypotheses have not been confirmed scientifically.

Because these side effects are relatively minor, the solution to avoid them is fairly simple. The best course of action is to take things slowly when you begin using probiotics. This means taking a small dose and gradually working your way up as needed instead of going all out immediately. Unfortunately, this is not the only issue we must consider when using probiotics.

#2: Some Probiotics Can Increase Histamine Levels

Our bodies are designed to repel threats and protect themselves from illness and injury, and they have access to several resources capable of executing that mission. Unfortunately, many of our bodies' defenses are double-edged swords and can backfire under certain conditions. One defense mechanism in human biology is histamines, a molecule our immune systems synthesize to eliminate threats within the bloodstream. High histamine levels trigger an increased blood flow to the affected area to try and cleanse the harmful molecules that have infiltrated the body. While critical to our body's health, this process has side effects that can be disruptive and unpleasant. 

High histamine levels generate swelling in the affected area and induce certain allergy symptoms like itchiness, difficulty breathing, and watery eyes. These issues are usually short-lived since our bodies produce diamine oxidase (DAO) to break down the histamines in our system. When our DAO levels are low, the histamines in our body manifest unopposed and can oversaturate the bloodstream. This leads to chronic symptoms of histamine production that can make normal bodily functions almost impossible.

This information is relevant to probiotic use because certain strains have been linked to increased histamine production. Specifically, the following strains:

• Lactobacillus buchneri
• Lactobacillus helveticus
• Lactobacillus hilgardii
• Streptococcus thermophilus

People with DAO deficiencies should avoid these particular strains since using them could cause excessive histamine production. This side effect of probiotic use falls under the category of issues that require an underlying issue. Combined with the fact that only certain strains cause this effect, it is easier to avoid than some other side effects.

#3: Probiotics Can Trigger Headaches

One of the most common methods for introducing probiotics to our system is to consume foods rich in probiotic organisms. You might have noticed that some of the most common strains are preceded by the genus Lactobacillus. The prefix "lacto" is easily connected to dairy products since the "lacto" prefix is part of the lactic acid found in many probiotic organisms. This is because most of those bacteria are found in dairy products, making them the most common source of naturally occurring probiotics. Another important component of certain probiotic-rich foods is biogenic amines. Biogenic amines form when protein-rich foods age or are fermented by bacteria. 

Since probiotic organisms are bacteria, they ferment many probiotic-rich foods and have biogenic amines. Yogurt is the most famous example of fermented probiotic food and bears biogenic amines. Unfortunately, biogenic amines have compositions that do not necessarily agree with us. Biogenic amines are composed of histamine, tyramine, tryptamine, and phenylethylamine. 

All of these molecules affect the bloodstream and body in ways that can be taxing, especially since the biogenic amines these molecules create have their own effect on the body. Biogenic amines can excite the central nervous system and alter blood flow in the body.

Independently, these might seem like minor issues, but they can cause unpleasant consequences. Biogenic amines can trigger headaches in those with sensitivity to them, making them a problem when consuming probiotics fermented like this. One study determined that low-histamine diets reduced headaches in 75% of the test subjects. This proved a direct connection between the consumption of histamine and amine-rich probiotics and increased headaches. 

Like all the side effects we have discussed, this issue is rare and will unlikely affect you. Even if you are sensitive to these biogenic amines, they can be circumvented by using supplements instead of probiotic-rich foods. While this might not be ideal for some, it can help you avoid suffering headaches caused by fermented foods.

#4: Probiotics Can Increase Risk of Infection

The rarest side effect of probiotics also doubles as the most serious and relates to an issue we all fear concerning bacteria. While there are beneficial bacteria, sometimes exposure to something that is supposed to help us causes more harm. Most of the population can use probiotics without concern, but some people suffer from rare susceptibility. In extremely rare cases, the bacteria or yeast in a probiotic can enter the bloodstream and cause infections. 

This only affects a small demographic susceptible to infection, meaning the average person will not have to worry about this. Unfortunately, some will need to avoid probiotics because of their physical condition.

This effect is most prevalent in people with suppressed immune systems because their bodies cannot fight infections normally. The same issue can be seen in people who have recently undergone surgery or have installed venous catheters. The former weakens the immune system, while the latter provides a direct path for the bacteria to a sensitive region of our anatomy.

Fortunately, the odds of infection are staggeringly low, even in individuals with a compromised immune system. It has been estimated that only 1 in 1,000,000 individuals who use Lactobacillus probiotics will develop an infection. This translates to a 0.0001% chance of infection.

The odds are even more favorable for yeast-based probiotics, with which only 1 in 5,600,000 users develop an infection. Therefore, yeast-based probiotics have a 0.000018% chance of causing an infection in users. Even when an infection does occur, it can be easily treated since known cases have responded extremely well to traditional antifungals. Unfortunately, there are rare scenarios where the infection has killed the patient, but this has extremely low odds. 

Despite the severity of certain infections, those caused by probiotic use are almost impossible to contract without an underlying condition. Even then, your odds are favorable, though you should still avoid them to avoid unnecessary risk. 

#5: Some People Are Allergic to Probiotics

Sometimes the simplest issues are the most common, and this principle can be applied to the fact that some people are allergic to probiotics. In a world of infinite genetic variance, it was inevitable that a portion of the population would develop allergies to probiotic organisms. While allergies to the microorganisms are unlikely, their host can be a source of contention for many people. Millions of people are allergic to yeast and lactose, both of which are common hosts for probiotic organisms. Most probiotic foods are dairy-based because some of the most powerful bacteria thrive in dairy.

People who are allergic to the host substance of a probiotic will have to verify the ingredients of their product to ensure they do not compromise their health. Fortunately, this issue is easily overcome since many probiotic supplements forgo a host substance in favor of a powder base. If you have allergies, read the label carefully before using a probiotic supplement of any kind.

Finding the Right Blend

Probiotics are powerful tools that have proven to be a valuable addition to millions. Unfortunately, nothing is perfect, and there will always be risks when using a new substance to improve your health. The silver lining is that the side effects of probiotic use are either negligible or rare enough not to pose a threat to most people. Nevertheless, we recommend caution before introducing a probiotic to your system. Ideally, you should consult a physician to determine your susceptibility to probiotics, if any. If you are cleared to use them, the only concern left is finding a reliable supplement.

We at Teami can help you find the probiotic supplement you need without worrying about artificial ingredients. Our Gut Love Probiotic + Prebiotic Powder provides a daily dose of probiotics from the Lactobacillus family. While it does contain Lactobacillus, it is 100% vegan and dairy-free, meaning there is no risk of a lactose allergy reaction. Nevertheless, we stress our earlier point of verifying your allergies and immune health first. Otherwise, we encourage you to try our product for yourself and see what it can do for you. After all, finding the right blend is a Teami effort.