7 Science-Backed Signs That Your Gut Needs Probiotics

There’s been enough buzz surrounding gut health, the gut microbiome, and supplements to put probiotics on the map. But what are the signs you need probiotics in case you’re not already getting enough?

Like, how many jars of sauerkraut do I need to eat? Answer: none, of course, unless you want to. Or should I take a probiotic supplement to cover my bases, just in case?

We’ll break down the importance of probiotics, how to know when you need them and in what quantities, and share what the data says about supplements or enriched-probiotic foods vs. natural ones like yogurt, kimchi, kombucha, tempeh, miso, and so forth.

Have a gut feeling about what the science will tell us? Let’s get into it and see what are the signs you need probiotics.

What are the signs you need probiotics

What are the signs you need probiotics?

The reason why you’re thinking of taking probiotics is likely to balance out your gut microbiome. Sure, there are things you’re probably trying to treat specifically (better digestion, a yeast infection, and so forth) but it all starts with the gut.

Like how there are “good fats” and “bad fats,” our bodies have both “good bacteria” and “bad bacteria.” The idea is that our “good bacteria” far outweigh the harmful ones… as long as our gut microbiota is healthy and balanced.

What is the gut microbiome?

Our bodies are made up of about 39 trillion microbes, of which the vast majority live in the large intestine. This is mainly what we think of as our gut microbiome, and the makeup of it depends on several factors.

Some factors are out of our control, like our DNA and what was imparted to us from our mothers at birth and through breast milk. But later on, our diets, drinking alcohol, age, stress levels, and environmental exposure affect the composition of our gut microbiome.

Harmful things that decrease the variety and health of our gut microbes — tipping the odds in favor of harmful bacteria leading to disease — include ultra-processed foods, infectious illnesses including food poisoning, and antibiotic use.

An imbalanced microbiome is problematic as its smooth operation is imperative to our immune system and digestion. A whole array of poor health side effects, which we’ll go into below, signal the need for probiotics to get our microbiome back on a healthy, even keel.

What Are Probiotics?

Probiotics are foods and health supplements that provide live, beneficial cultures of a specific microbe to your body. Mostly, they’re eaten or taken as a pill or powder, but there are topical creams as well aka when you have a yeast infection.

Different probiotic microbes help with different things, so ideally you would identify the problem and choose a probiotic specifically for that after doing a bit of research. (This is a great research paper that can help point you in the right direction, and check with your doctor too.)

Just know that with a probiotic supplement, the FDA does not regulate them. There have been tests showing that different supplements have less than their promised amount of probiotics, or a different one altogether.

That’s why if you do eat foods that have probiotic additives, make sure they’re brands you trust. For us, while we try to eat most probiotics naturally, we also supplement with high-quality shakes like LyfeFuel and Shakeology.

If, instead, you’re like us and want to eat probiotic-rich foods to naturally add variety and health to your gut microbiome, here are excellent foods to include in your diet.

  • Kefir
  • Kombucha
  • Yogurt
  • Soft cheeses (cottage cheese, gouda, raw cheddar, Swiss, parmesan, Gruyère, provolone)
  • Tempeh
  • Miso
  • Kimchi
  • Sauerkraut
  • Sourdough bread
  • Naturally fermented olives
  • Apple cider vinegar
  • Fish sauce
  • Sour pickles

Always check ingredient lists to see if there are “live or active cultures,” mostly for yogurt, and the less processed, the more probiotics. That’s what we love most about making our homemade kefir.

What are the Signs You Need Probiotics?

There are several signs that your body gives when it needs a boost from probiotics.

While, frustratingly, some of these signs seem run-of-the-mill, or could be from anything, adding probiotics naturally to your diet is a great place to start as you make lifestyle changes to address your ailments.

In certain cases, supplements may be recommended by doctors in specific scenarios, but here are the most common signals that your body will give.

1. Digestive Issues

If you’re not regular or experience the extremes of diarrhea or constipation, your gut microbiome could be out of whack and not digesting your food as well as it should.

Whether the diarrhea is caused by food poisoning, antibiotic use, or otherwise, it’s an indication that your body has too few healthy bacteria in the gut.

On the flip side with constipation, one cause is that your gut is overgrown with unhealthy bacteria. Before we started our health journey together, this was Ryan. His record was 14 days without movement. Probiotics helped, but ultimately he credits eating less ultra-processed foods.  

Either way, adding an array of probiotic-rich foods to your diet will help rebalance and support healthy microbe populations.

This also goes for excessive bloating or gassiness.

2. Acne and Other Skin Problems

Didn’t think your skin problems could be related to a gut microbiome imbalance? Well, it turns out that skin problems like acne and rosacea could be a sign that you need probiotics.

In fact, scientists have dubbed this relationship the “gut-skin axis,” and it is a very real thing.

A 2023 review found that multiple studies showed positive effects on skin health by using probiotics through oxidative stress reduction, lowering inflammation, and boosting overall immunity.

The point of a healthy gut is to flush out toxins, and when that doesn’t happen perfectly, the results can manifest on your skin. Also, skin conditions are often caused by certain bacteria, so if a topical cream (often a probiotic cream) or whatever was recommended by your dermatologist isn’t helping, support your skin health by consuming more probiotics.

3. Getting sick often

While it could just be flu season, getting sick often is a sign of a compromised immune system and an imbalanced gut microbiome. And it doesn’t have to be that way.

An estimated 70-80% of your immune cells live in your gut, so saying what you eat directly influences your immunity is an understatement.

The role of probiotics and immunity is a well-studied topic, given its particular importance in developing countries in controlling infectious but preventable disease outbreaks. And, mostly, it all comes down to nutrition.

Specifically, with three things: dietary fiber, prebiotics, and probiotics. If you cover these bases, you’re well on your way to great health.

We’ve researched extensively how much fiber can help with weight loss and overall health, and include it as one of the five numbers to track in our 30-Day Weight Loss Challenge. Head over there and to our High Fiber Foods Chart for more great and helpful information.

Finally, if you’re wondering what prebiotics are, they are foods that stimulate, feed, and bolster your current populations of healthy gut bacteria. Examples of prebiotics include almonds, bananas, whole grains, raw garlic, raw onions, peas, honey, and beans.

4. Recovering from an illness

When considering what are the signs you need probiotics, one of the most obvious ones is if you’re recovering from an illness.

This could be something from food poisoning — which can wreak havoc by letting bad bacteria grow unchecked — to an illness that requires antibiotics.

By the very definition of it, an anti-biotic is the polar opposite of a pro-biotic. Indiscriminately, an antibiotic kills both good and bad bacteria in the hopes of killing the bad ones that got you sick.

But many good microbes are innocent bystanders in that scenario, making it incredibly important to replenish healthy microbe populations with probiotics.

5. Fatigue

Just as there is a “gut-skin axis,” there is also a “gut-brain axis.”

It’s no surprise, given that your gut alerts your brain when you’re full, for example, but research has taken it a step further in learning how to combat fatigue.

With new research coming out about long COVID and other post-infectious fatigue (aka, the feeling of continued exhaustion after battling an infection or illness), probiotics have taken the main stage.

These studies, like this and this, remain small, but the results are promising: a probiotic regimen can increase energy levels, reduce fatigue, and improve quality of life scores when tested against a placebo.

6. Depression or Mood Swings

Considering that 90-95% of your body’s serotonin (the hormone known for regulating mood) is found in your gut, it’s  no wonder that a balanced gut microbiome is so important.

Similar to fatigue as a sign that you need to take a probiotic, depression and mood swings are also indicators. This is because they’re all part of the same gut-brain axis.

A 2023 literature review found increasing evidence linking your gut microbiota to your mental health.

The review found that depression and anxiety increase the permeability of your gut barrier, inducing an inflammatory response. This is what leaky gut syndrome is.

It’s a bad cycle to start, as leaky gut syndrome allows toxins to enter the bloodstream and induce an even stronger inflammatory response — as if cramping, bloating, headaches, and joint pain weren’t enough.

This is where probiotics and the management of healthy gut bacteria come in.

Furthermore, a recent meta-analysis confirmed that probiotics could help with mild to moderate depression. For severe depression, antidepressant drugs were still more effective, but the support for consuming more probiotics was strong and complimentary.

7. Insomnia or poor sleep

The verdict is still out there for some scientists, but a growing body of evidence supporting probiotics and sleep quality is coming to light.

The reason for the hesitation is that this is another topic that’s challenging to study. After reviewing several meta-analyses (like here and here), though, we think the results are promising, specifically for people who suffer sleep disturbances from stress.

Serotonin, which we mentioned above, is mainly produced in the gut. It is critical, alongside dopamine, in supporting sleep quality. Serotonin is also necessary for the body to make melatonin, which regulates your sleep-wake cycle.

These studies found that a probiotic intervention can help higher quality sleep, as self-reported in the studies. More research is needed on the topic, but for those trying to get a good night’s sleep, it’s worth the try.

Inconclusive Signs You Need Probiotics

When writing this article, we did our best to fact-check thoroughly with recent studies, because many pro-probiotic websites shouted from the rooftops that nearly everything could be treated. After all, the probiotics industry is valued at USD 79 billion in 2024.

However, this isn’t the case. Not because probiotics don’t “fix” a plethora of issues, but because it’s very hard to study. Everyone’s gut health situation is different, and there are also dozens of different strains and genera of probiotics. Dosage is an issue, too.

For example, we were hoping to include commonly cited signs such as allergies and trouble with weight loss after making lifestyle changes. However, studies are inconclusive for both.

Specifically for weight loss, only a high dosage of probiotics seemed to work marginally well but it wasn’t very convincing, according to a study published in Nature.

In this case, we think you have to approach a weight plateau the old-fashioned way, although every diet can benefit from probiotics. Just, perhaps, not for weight loss unless it’s linked to digestive issues.

Closing Thoughts on they symptoms of a probiotic deficiency

Those are the 7 signs you need probiotics.

We’ve covered a wide spectrum of symptoms that could mean your gut microbiota is imbalanced and could use probiotic support. While some of them are vague — who doesn’t have poor sleep or digestive issues from time to time? — it goes to show how much a healthy and balanced diet, including probiotics, can put your best foot forward and your body in the best shape.

The good news is that there doesn’t seem to be a downside to consuming probiotics, especially naturally through foods like yogurt, miso, and kombucha.

Just be careful when considering probiotic supplements. It isn’t regulated and what’s written on the bottle’s label doesn’t necessarily mean it’s accurate. For us, we prefer the whole food route unless your doctor advocates for a more precise and concentrated probiotic intervention.

Despite the growing focus on probiotics, all you can do is look for the signs that you might need them and do your best. From our research, at-home, stool-sample kits that show your gut microbiome composition aren’t super helpful because there’s no baseline of what “the healthiest microbiome possible” should look like.

So, I guess you’ll just have to follow your gut instincts on this one!

For more resources and guides about clean eating, such as our guide on how to eat clean as a beginner, head over to our Clean Eating Page.

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Hey we're Ryan and Alex

The creators of Ryan and Alex Duo Life. We are a husband-wife duo and “lifestyle engineers.”

After eight years working in the corporate world as engineers, we left our high-powered jobs to tackle our true passion — helping couples engineer their best lives.

The synergy of our engineering minds and ten years of health coaching experience produced Ryan and Alex Duo Life. Our mission is to help you transform your bodies, minds, and relationship as a couple.

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