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Evidence Based

This article is based on scientific evidence, written by experts and fact checked by experts.

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This article contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.

6 Signs That Your Probiotics Are Working

Written by Dr. Michael Ruscio, DC on May 2, 2025

Written by Dr. Michael Ruscio, DC on May 2, 2025 — Reviewed by Hilary Watts

• 6 Signs Probiotics Are Working|
• What to Look for in Your Probiotic|
• How Long Should It Take to See Improvements?|

You’ve likely been taking probiotics for a while now, knowing about the variety of health benefits they offer. But how do you know whether or not they’re working?

Beneficial microbes are already living in your gut, but chances are they could use a boost—or at least a rebalancing. Supplementing your natural supply of good bacteria with probiotics can help improve your digestive health, mental health, mood, immunity, and skin. That’s because your gastrointestinal system and the gut microbiota that live there play a key role in your overall health and wellness. Each of these seemingly unrelated health categories is intimately tied to gut health.

You don’t have to understand every detail of how probiotics work to reap their health benefits, but knowing the basics might help motivate you to keep taking them to maintain a healthy gut. An even greater motivation is to notice and experience the real benefit of taking probiotics consistently: symptom relief.

So, what are the signs probiotics are working? Let’s dive in.

6 Signs Probiotics Are Working

The most obvious way you can tell if your probiotics are working is that your symptoms are improving. Sometimes you’ll notice improvements within a week, while in other cases, it may take a month or more to see changes. 

Inflammation is likely at the root of just about every chronic illness we know of. An inflamed gut can even develop microscopic holes in its lining, leading to leaky gut syndrome, a condition linked to many health challenges. Reducing inflammation is a key component of relieving many symptoms, and probiotics can help with that. 

Since your gut is so integral to your overall health and well-being, it makes sense that reducing gut inflammation with probiotics would benefit your whole system and reveal the following improvements. 

1. Improvements in Digestion

Improvements in digestive symptoms, like constipation, diarrhea, bloating, gas, and acid reflux, are good signs that probiotics are working for you.

Probiotics have many great benefits for your digestion and overall health. One big reason is that they can help reduce inflammation in your gut and elsewhere 1 2. When your gut is less inflamed, it can positively impact your entire body.  

Probiotic supplements help in part by crowding out bad bacteria in your gut. This is why probiotics are often recommended for treating gut imbalances (dysbiosis) and small intestinal bacterial overgrowth (SIBO). 

By healing your gut with high doses of good probiotic bacteria and fungi, it’s likely that the following digestive problems will improve:

• Constipation and diarrhea 3 4
• Abdominal pain, excessive gas, and bloating 5 6 7
• Acid reflux and heartburn 8

And if you tolerate them well, probiotic-rich foods like sauerkraut, kimchi, kefir, and kombucha are great to add alongside probiotic supplements to help improve digestion. 

2. Improved Mood and Cognitive Function

You’ll know your probiotic is working if you’re experiencing less brain fog, a better mood, and lower stress levels.

There’s a well-established connection between the gut and the brain—the gut-brain axis—that helps explain why so many psychological challenges come with digestive issues like irritable bowel syndrome (IBS) 9. 

Probiotics can provide positive benefits for your mood, mental health, and cognition.

For example, research shows that probiotic dietary supplements can help relieve mental health conditions like anxiety 10 and depression 11.

Other studies show that the anti-inflammatory effects of probiotics can help improve cognitive function, especially memory 12.

3. Lower Stress and Better Sleep Quality

Although it’s unclear whether gut health has a greater effect on brain health or vice versa 13 14, the scientific medical community generally agrees that the two are intimately linked 15.

That’s why improvements in how stressed you feel and how well you sleep are good signs probiotics are working.

We know that stress is directly linked to inflammation and can increase digestive symptoms like bloating and even nausea 16. Stress can also make your gut hypersensitive, so if your digestive system is already stressed, you’re likely to feel the symptoms even more 17. 

Unfortunately, this can create a cycle where stress worsens digestion, and digestive issues add more stress, making the problem repeat itself.

The same goes for sleep—poor sleep can upset the balance of beneficial bacteria in your gut, and an imbalanced gut can negatively impact your sleep.

But the good news is that taking a multi-species probiotic supplement can relieve stress 18 and improve sleep quality 19.

4. Reduced Autoimmunity

I can’t claim that probiotics can definitively cure an autoimmune disease, but you’ll know your probiotic is working if you begin to experience fewer flare-ups and fewer hyper-immunity reactions.

Your immune system plays a key role in your overall health, and since most of your immune system is in your gut, digestive health is also a good indicator of your well-being. 

The immune system creates inflammation to protect you from harmful microorganisms. For example, your body generates a fever to fight off a cold, or a cut becomes red and swollen to prevent infection.

If your gut has too many harmful bacteria or chronic inflammation, it can trigger autoimmune issues, allergies, or food sensitivities.

A gut with a balance of healthy gut flora helps regulate inflammation, turning it on when needed and off when it’s not. When this balance is disrupted, autoimmune conditions like celiac disease, atrophic gastritis, Hashimoto’s thyroiditis, or rheumatoid arthritis may arise.

If your immune system feels more balanced (you’re getting sick less, having fewer flare-ups, or having fewer allergies), you know your probiotics are working 20.

5. Skin Improvements

A tell-tale sign probiotics are working for you is if your skin condition clears up.

The relationship between gut dysbiosis and skin health is well-studied and established 21.

Some skin conditions, like psoriasis or vitiligo, indicate an autoimmune condition, but others, like acne or rosacea, do not. Regardless, many skin conditions may point to a gut microbe imbalance, or dysbiosis 22. 

If you’ve seen a dermatologist about acne or rosacea, you’ve likely been prescribed an antibiotic that cleared the problem temporarily, only for it to return with a vengeance. This happens because one of the unwanted side effects of antibiotics is to kill even the good bacteria in your gut and on your skin that help keep your skin’s natural protective barrier intact.

Listen to this case study of one of my clients who experienced relief from skin rash, acid reflux, and loose bowels after changing his diet and adding in probiotics and HCl (hydrochloric acid) to help with stomach acid. 

Certain skin conditions are trickier than others to treat, but adding a high-quality probiotic to your efforts is a good idea.

6. Fewer Vaginal Infections

The vagina, like the gut, depends on a healthy balance of bacteria. Women taking probiotics may experience fewer episodes of bacterial vaginosis, with a reduction in how often infections occur and how severe they are 23.

Probiotics may also be helpful if you’re taking antibiotics for an existing infection, as they can reduce unwanted side effects like diarrhea or abdominal pain 24. 

What to Look for in Your Probiotic

There are three main types of probiotics, all of which help restore gut health by reducing inflammation and reversing dysbiosis. 

The most common type, found in grocery stores, health food stores, and pharmacies, is a Lactobacillus/Bifidobacterium blend. These probiotics usually need to be refrigerated unless the label says otherwise, and a good one should contain billions of CFUs (colony-forming units). 

We find the best results come from a triple-probiotic approach, using these three probiotic types: 

1. Lactobacillus/Bifidobacterium blend (commonly found in stores)
2. Saccharomyces boulardii (a beneficial yeast)
3. Soil-based probiotics (mainly Bacillus species)

This combination provides a diverse and effective probiotic balance, which we’ve seen significantly improve gut health in our patients. Here’s a dosing strategy we typically recommend:

How Long Should It Take to See Improvements?

Not everyone will feel dramatic improvements when taking probiotics—and that’s okay.

Sometimes probiotics simply aren’t the right fit for your body or current symptoms. If you’ve been consistent for 6–8 weeks and still aren’t seeing benefits, it might be time to try a different formula, adjust the dose, or pause altogether 25.

Here are a few reasons probiotics might not be working as expected:

• Relying on a single strain: Some probiotic supplements only contain one type of probiotic, and others are multi-strain. Though some people may have great results with a single strain, if you haven’t noticed a difference in your health, it may be time to try a multi-strain formula. 

• Ignoring diet and lifestyle: Probiotics can do wonders for gut health, but they aren’t a fix-all. It’s important to remember that you can’t fix a nutrient-deficient diet with supplements. This is why, at the clinic, we emphasize building a healthy foundation with diet and lifestyle first, before adding supplements like probiotics.
  
• Underlying Imbalances: Probiotics can help rebalance your gut—but if there are deeper issues like SIBO or chronic inflammation, they might not be enough on their own.
  
• Improper Use: Timing, storage, or taking probiotics alongside antibiotics can affect their potency and impact.
  

Listening to your body is key. If your symptoms worsen or stay the same, that’s useful information—and a sign to reassess your approach.

Listen to Your Body

Your gut plays a major role in your overall health and well-being. If your gut microbiome is imbalanced, it can lead to inflammation, mood and cognitive changes, autoimmune issues, and skin problems. Taking probiotics can help improve these areas over time, which is a sign they’re working.

Positive changes from taking a probiotic product won’t happen overnight. As the good bacteria in probiotics gradually replace the bad bacteria in your gut, you’ll start noticing positive changes in your overall health and well-being. Staying consistent is key to seeing results, and tracking your symptoms can help you and your healthcare provider understand your progress over time. 

We’d love to help you get started on your journey to better gut health. Reach out to our clinic for more information.

The Ruscio Institute has developed a range of high-quality formulations to help our clients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you. The information on DrRuscio.com is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment.