Understanding the Side Effects of Probiotics: What You Should Know

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You’ve probably heard of probiotics—you may even be aware that consuming this magic breed of live bacteria offers a treasure trove of health benefits.

Consuming probiotics can be very good for you—but there are some probiotics side effects you should know about before taking a regular dose of extra live bacteria.

At Smart Protein, we’re all about facts, knowledge, and balance. So, here we’re going to talk about the pros and cons of probiotics to help you make the best possible choice for, well…you.

Ready? Let’s go.

What are probiotics, exactly?

Good question. Basically, probiotics are what are commonly known as ‘gut-boosting good bacteria.’ You can find probiotics in certain fermented foods, including sauerkraut (a probiotic-rich culinary classic), some yoghurts (especially kefir), tempeh, kimchi, and pickles.

SmartFact: The average person has between 39 and 300 trillion (1) (no, your eyes don’t deceive you) bacteria living in their gut. Most gut-based bacteria are harmless (some are even beneficial), while some can cause illness or disease.

Taking probiotics is a way of maintaining or restoring the bacterial balance in your gut to keep you feeling happy, healthy, and energised.

As the friendliest bacteria of the bunch, taking probiotics feeds something known as your gut microbiome—a melting pot of microorganisms that work together to maintain harmony in your gut.

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A probiotic supplement is designed to make the right gut microbiome adjustments on a daily basis so that you avoid illness, digestive issues, and immune system deficiencies (among other complications). 

So, getting a regular hit of probiotics can help you feel good day in, and day out.

SmartTip: Read our essential guide on probiotics to dig deeper into this gut-boosting subject.

The health-boosting benefits of probiotic supplements

Now that you’re up to speed with the probiotics basics, let’s take a quick look at the potentially health-heightening benefits of eating probiotic foods or taking supplements…

  • Possible assistance with weight loss
  • Better skin and complexion
  • More efficient immune system functionality
  • Can play a part in combating depression
  • Improved digestion (probiotics can help tackle irritable bowel syndrome)
  • Reducing inflammation and boosting your energy levels

As you can see, keeping your probiotic bacteria in check comes with a host of potential health benefits—but to maintain a solid balance—it’s important to make sure you don’t overdo it.

The potential side effects of probiotic supplements

As you know, there are two sides to every coin. So, in addition to understanding the benefits of getting extra good bacteria in your gut—you should also know about the possible side effects of probiotics. It’s the Smart way, after all.

So, here’s what you should know about the potential pitfalls of taking probiotics…

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1. Undesirable digestive issues

Okay, given the fact that probiotics exist to help improve gut health, this may sound counterintuitive. But, some people may actually experience unpleasant or uncomfortable digestive issues. 

This isn’t a common side effect (if it were, no one would take probiotic supplements), but some people can suffer from excess gas and bloating.

The reason for this reaction in a small segment of the population is unknown. But, to test the waters and see if fermented foods or probiotic supplements suit your gut microbiome—you should start with a smaller dose and increase the amount over time.

If you do happen to experience gas or bloating, it's always best to seek the advice of your doctor or a medical professional who specialises in gut health.

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2. Possible headaches

Another potential side effect of taking probiotics is headaches. As you no doubt know, headaches can be nasty and quite debilitating—and although this side effect is fairly rare—it’s worth knowing about.

You’re more likely to experience headaches if you eat a lot of probiotic-rich foods because of substances called biogenic amines.

These biogenic amines include the likes of phenylethylamine, tyramine, and histamine. If you happen to be sensitive to any of these substances, your central nervous system can become excited and alter your rate of blood flow, which may lead to—you guessed it—headaches.

SmartTip: If you are unlucky enough to experience headaches, keep a food diary so you can see which food in particular acts as a trigger. That way, you can eliminate it from your diet. Oh, and taking a trusted probiotic supplement can help keep headaches at bay.
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3. Raised histamine levels

Just moments ago, we touched on biogenic amines—including histamines (think, hay fever). Some probiotic strains can raise histamine levels quite significantly.

When this happens, these slightly more pesky strains of probiotics can cause side effects that include…

  • A runny nose
  • Watery eyes
  • Redness or swelling on the skin or body, particularly in or around the facial area
  • Some trouble breathing

These side effects aren’t hugely common—and it’s usually people with a histamine intolerance that are affected by these particular probiotic strains.

If you think you might be allergic or intolerant to histamines, check with your doctor before upping your probiotic bacteria dosage in any way.

4. Possible risk of infection

Another possible complication linked to ‘good gut bacteria’ in food or supplement form is an outside risk of infection.

This is arguably the rarest of all the side effects mentioned, but it’s worth knowing about nonetheless.

For anyone with compromised immune systems, the risk of infection as a result of taking probiotics is higher. 

Why? Well—and we’ll stress this again—in rare cases, certain bacteria or yeasts can enter the bloodstream, creating infections in the process.

For most people, adding probiotics to your diet from a supplement or food source is completely safe. But, if you’re critically ill, have a weakened immune system, or you’re concerned about the risk of infection, you should talk to a medical professional before adding probiotics to the mix.

Probiotics the Smart way

Your gut microbiome adjusts to the foods and bacteria you feed it. But not all probiotics deliver the goods when it comes to fighting bad bacteria.

Knowing the potential side effects (albeit rare) and digestive discomfort that consuming probiotics can cause means that you can make a choice that is safe and healthy for—you.

Healthy bacteria is great for your gut. Sadly, as we’ve established, eating fermented-style foods or taking a regular probiotic supplement isn’t ideal for everyone’s immune system.

That said, understanding the risks (as well as the benefits) that might impact you, checking the ingredients lists of supplements, and following the correct dosage is more likely to offer you body-boosting rewards rather than uncomfortable side effects.

In summary, taking probiotic supplements the Smart way is likely to make you feel happy, healthy, and energised.

Extra safety info you need to know

To take probiotics safely and reduce the risks of any potential side effects, here are some additional SmartTips for your reading pleasure…

  • Check with your doctor to see if the specific foods or supplements you’re looking to take will suit you and your digestive system
  • Dispel any false probiotic health claims by looking at reviews and testimonials before committing to a supplement
  • Always adhere to the right dosages and take them as part of a healthy, balanced diet
  • As mentioned, start with smaller doses of probiotics and increase your intake over time to stay safe and maintain a natural balance within your gut
  • Take probiotics supplements around 30 minutes before you start eating to get the biggest health-boosting benefits

So, who shouldn’t take probiotics? 

By taking too many probiotics, most people will experience gas and bloating when it comes to probiotics. But, generally speaking, by taking them the Smart way, most people can and will benefit from probiotics. 

FYI: As you’ve probably gathered by now, there are people who should take care and consideration before starting their supplementation journey. 

For your information, these people include…

  • People with an immune system that is compromised
  • People with pancreatitis
  • People recovering from a serious health condition
  • People with severe allergies (check with your doctor to see if probiotics are an option)
  • Infants with short bowel syndrome
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Try Smart Protein’s probiotic gummies

Our taste bud-tingling Smart Protein Boost & Balance Apple Cider Vinegar Gummies give you a big body boost.

A supplement designed to support the brain and gut functions you need to feel on top of your game, each gummy is packed 1000mg of apple cider vinegar, beetroot, and pomegranate juice to make you happier, healthier, and help you lose weight (if that’s one of your goals).

Our gummies also come crammed with B12 (in addition to a treasure trove of additional ingredients) to improve immune support and keep your metabolism in tip-top shape.

Two gummies a day is the perfect way to maintain a healthy blood cell formation, fight fatigue, give your energy levels a big boost, and keep your gut healthy.

So, what makes Smart Protein different? 

Our range of Smart products is carefully formulated to target a wide range of wellness and fitness goals to suit people from all walks of life.

As a standard, our products boast these perks…

  • No added sugar
  • Zero artificial colours
  • Natural flavourings
  • The highest quality ingredients
  • Gluten-free
  • Soya free

Our gummies are safe, tried, and tested. If you’re ready to start your journey, try our gummies and take that first step on your pathway to better gut health. 

We hope this guide offers all of the advice you need to weigh up the pros and cons of probiotic supplements. For more insider advice from Smart Protein HQ, check out our essential guide on Ashwagandha.


Can Probiotics cause stomach pain?

By introducing new bacteria to your microbiome, you might experience a little stomach irritation, excess gas, and bloating as your body adjusts. But, these side effects are usually mild, and by gradually increasing the dose of probiotics you take, you can usually avoid any potential stomach discomfort.

Can Probiotics stop bleeding?

While there’s no direct evidence to suggest that probiotics can stop bleeding, there are studies that show (2) that these amazing living microorganisms can help accelerate the healing of skin tissue and surgical wounds.

Can probiotics cause thrush?

There’s not enough research to suggest that probiotics can cause thrust or any kind of yeast infection. It’s not a known side effect and an outcome that’s unlikely when taking probiotic supplements.

Can probiotics cause diarrhoea?

While probiotics generally benefit gut health, they do contain something called short-chain fatty acids that can cause stomach irritation. Sometimes, these fatty acids can temporarily cause diarrhoea. By sticking to the recommended dosages and allowing your body to adjust, you can overcome this issue swiftly.

Can probiotics cause gas?

Yes, while probiotics are good for your gut health, they can cause some gas and bloating while your microbiome gets used to the new mix of good bacteria. But, these symptoms are usually mild and generally pass. If you do find any gas or bloating problems persist, check in with your doctor.

Can probiotics cause bloating?

Yes, while probiotics are generally great for your gut health, they can cause a little bloating while your microbiome adjusts to a new mix of healthy bacteria. But, these symptoms are generally mild and don’t last long. If you do find that your bloating problems persist, talk to your doctor.

Can probiotics cause constipation?

While this is a pretty rare side effect, certain probiotics can slow down digestion in some people, causing bouts of constipation. If you do experience these symptoms, talk to your doctor about the issue.


Smart Protein is committed to sourcing only the best and scientifically-backed research in our articles.



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