New to Probiotics? Here are 7 Signs They're Actually Working

Your stomach and intestines contain beneficial and harmful bacteria. When this balance is disrupted, you may experience digestive issues or other health problems.

Probiotics are living microorganisms that help improve the balance of bacteria in your gut. They are usually found in foods or supplements, containing beneficial bacteria and yeast that can improve gut health. Probiotics help in several ways, such as: 

• Assisting digestion

• Lowering the acidity in your gut 

• Stopping harmful bacteria from taking over

• Supporting your immune system (1) 
  

If you're new to probiotics and unsure if they're actually making a difference, you're not alone. With so many options and health claims, it can be hard to tell if they’re working. However, your body gives subtle signs when probiotics are doing their job.

“A few of the most common signs probiotics are working include having fewer infections, more regular and healthy bowel movements, and less bloating or gas,” says Melissa Mitri, MS, RD, Nutrition Writer and Owner of Melissa Mitri Nutrition. 

In this article, we'll highlight seven signs, backed by science and expert insights, that show your probiotics are working and improving your overall health.

1. Improved Gut Health

Different probiotic strains may help specific symptoms, and they also support gut health by reducing inflammation and improving digestion, as per a 2020 study published in the Journal of Clinical Medicine (2). The study also found that probiotics can help improve stool frequency and consistency in Irritable Bowel Syndrome with diarrhea or constipation. However, their effects on pain, bloating, and gas vary. 

Another meta-analysis of 15 studies suggests that probiotics are a safe and natural way to relieve constipation (3). Researchers found that probiotics, especially those with multiple bacterial strains, improved bowel movements and reduced bloating. Probiotics also shortened gut transit time by about 14 hours and increased weekly bowel movements by nearly one. However, single-strain probiotics, such as Bifidobacterium lactis, were less effective.

This suggests that probiotics can help improve gut health, with multiple strains being more effective. “For better digestion, certain strains like Lactobacillus acidophilus and Bifidobacterium longum have been linked to easing IBS symptoms and improving gut health,” says registered dietitian Mitri.

2. Strengthened Immune System

Different probiotic strains work in different ways, so choosing a formula with science-backed probiotic strains helps support both your innate and adaptive immune systems.

Probiotics help strengthen your body's natural defense system and reduce inflammation caused by harmful germs by influencing specific immune signaling pathways. They work by shifting your immune balance, lowering allergic reactions, and increasing tolerance (4). 

One systematic review looked at studies on how probiotics may help with viral infections, including COVID-19. Researchers analyzed 21 studies and found that probiotics can reduce inflammation, lower viral load, and boost immune responses by increasing interferons and antibodies (5).

However, your overall diet plays a major role in immunity. Along with probiotics, a nutrient-rich diet with fiber, antioxidants, and vitamins helps strengthen your immune system and general health.

3. Improved focus and energy levels

Your gut and brain are deeply connected, constantly influencing each other. Research shows that many people with anxiety and depression also experience digestive conditions like irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD), highlighting this connection (6). By supporting gut health, probiotics can increase energy levels and improve focus.

Quality sleep is also essential for maintaining focus and energy levels. Probiotics can support better sleep and reduce fatigue, leading to improved concentration and increased energy.

A 2019 study explored whether probiotics can improve mood and well-being. Thirty-eight healthy people took either probiotics or a placebo for six weeks. Those taking probiotics showed better mood, less anger and fatigue, and improved sleep. While no major differences were found between groups, the results suggest probiotics can help with mood and sleep quality (7).

Another study examined whether probiotics can help brain health in older adults. Sixty-three people aged 65 and above took either probiotics or a placebo for 12 weeks. The probiotic group had less harmful gut bacteria, better mental flexibility, lower stress, and higher levels of a protein that support brain health called brain-derived neurotrophic factor (BDNF). The results suggest probiotic supplementation may support brain function and well-being in older adults (8).

4. Reduced Sugar Cravings 

Sugar cravings are linked to the gut, where trillions of bacteria help regulate appetite and cravings. An imbalance in gut bacteria can lead to increased sugar cravings, as some bacteria thrive on sugar and may influence your brain to seek more of it. Certain probiotic strains can reduce sugar cravings by promoting the growth of bacteria that don’t rely on sugar for energy. 

A recent 2024 study tested whether probiotics can reduce stress-related sugar cravings. Mice given Lactobacillus probiotics consumed 20% less sugar under stress than the placebo group. Probiotics also altered eating patterns and showed mild anti-stress effects, suggesting they may help control sugar cravings (9).

Therefore, if you notice fewer sugar cravings, it could be a sign that your probiotics are working.

5. Better Weight Management

Normal eating happens when your brain, gut, and gut bacteria work together in balance. But in food addiction, this balance shifts, making you crave food for pleasure rather than hunger. 

Probiotics can help with weight management and appetite control in obese women with food addiction, as demonstrated by a randomized clinical trial. For over 12 weeks, participants followed a calorie-restricted diet and took either probiotics or a placebo. The probiotic group showed significant weight loss, reduced body fat, and improved eating behavior (10). 

The participants also had more oxytocin (a hormone that makes you feel satisfied) and less NPY (a hormone that makes you feel hungry). This suggests that for people struggling with food addiction and weight management, probiotics can help by influencing appetite-related hormones and reducing the urge to overeat sugary foods.

6. Fewer Digestive Issues After Antibiotics

Another sign that your probiotics are working is experiencing fewer digestive issues after taking them. Taking probiotics after antibiotics can help reduce digestive issues like bloating, diarrhea, and stomach discomfort. As antibiotics kill both harmful and beneficial bacteria in the gut, it can lead to an imbalance and cause digestive issues. 

A systematic review and meta-analysis of 42 studies involving over 11,000 participants found that taking probiotics alongside antibiotics reduced the risk of antibiotic-associated diarrhea (AAD) by 37%. Higher doses and specific strains, like lactobacillus and bifidobacteria, were more effective, especially in those at moderate or high risk of AAD (11).

“It's best to wait at least 2–3 hours before taking probiotics after antibiotics to prevent the antibiotics from killing the beneficial bacteria,” Mitri suggests. 

It's also best to continue taking a high-quality probiotic daily for at least a month after finishing antibiotics to help restore healthy gut bacteria. Even if you took probiotics during your antibiotic course, extending their use can further support gut health.

7. Healthier Skin

Research shows a strong connection between gut and skin health, mainly through the immune system. Studies show that probiotics, whether taken orally or applied to your skin, may help prevent and treat skin aging by reducing oxidative stress, controlling inflammation, and supporting the immune system (12). 

Probiotics also help reduce acne and eczema flare-ups (13). Signs that probiotics are working include fewer breakouts, reduced redness, and less dryness, which is closely linked to skin health. However, results take time, and choosing the right probiotic strain is essential for best results.

How to Choose the Right Probiotic Supplement

When it comes to choosing the right probiotic supplement, quality matters more than anything else. To choose the best probiotics supplement for you, look for a product that contains the strains proven to support your specific health goals. 

For example, if you’re looking to improve your gut health or immunity, choose products with strains studied for those particular uses. 

“Additionally, look for products that have been third-party tested for safety and quality. If this is not the case, try to at least find products produced under good manufacturing practices (cGMP label), which ensures they are made under the highest quality standards,” advises Mitri. 

All Transparent Labs products are third-party tested and manufactured in FDA-registered facilities that follow strict GMP quality standards. Our Gut Health Probiotic Supplement contains ten potent strains, including Lactobacillus Acidophilus and Bifidobacterium Lactis, to support gut health, digestion, and immunity. This high-quality formula ensures maximum effectiveness and safety.

How to Take Probiotics for Best Results

For best results, it is recommended to take Transparent Labs Prebiotic Greens along with the Gut Health Probiotic Supplement to get the most benefits.

Research shows that prebiotics provide essential nutrients for probiotics, helping them survive and function better. This combination supports a healthy gut, improves digestion, and strengthens the immune system more effectively than probiotics alone (14).

How Long Does It Take to See Results?

According to dietitian Melissa Mitri, probiotics can start working in as little as a few days, but this depends on the individual, the dosage, the specific strain, and the reason for taking them.

“Depending on these factors, the full benefits may occur anywhere from a few days to 3 months. For example, someone taking a probiotic for a short-term issue such as antibiotic-associated diarrhea may see relief in a few days, while those taking it for long-term digestive health or immunity may not see a big difference until a few months of consistent use.”

Consistency is essential when taking probiotics, as their benefits build over time. For the best results, it's important to take them regularly and as directed. 

When to See a Doctor

Always speak to a healthcare professional before starting probiotics to weigh up the pros and cons, and make sure your plan is tailored for you. Side effects of probiotics are more common in the first week or two. Therefore, if you’re experiencing mild digestive symptoms like gas, bloating, or diarrhea in the first few days, this may be your body simply adjusting to the probiotics. 

However, if it lasts longer than two weeks and gets worse or to the point where it’s impacting your daily life, speak to your doctor to see if there is another underlying cause of these symptoms. In addition, if you develop any allergic reaction symptoms such as hives, throat swelling, or difficulty breathing, stop taking your probiotic and seek medical advice straight away.

The Bottom Line

A balanced gut microbiome is essential for a healthy digestive system. Probiotic bacteria, often found in dietary supplements, can help restore your gut flora, improve irregular bowel movements, and support your general health. They may also reduce the risk of yeast infections by maintaining a healthy microbial balance.

While probiotics can support gut health, they work best when combined with healthy lifestyle choices. Eating a balanced diet rich in fiber, fermented foods, and essential nutrients helps nourish beneficial gut bacteria.

Staying hydrated, managing stress, getting enough sleep, and exercising regularly also play an important role in maintaining a healthy gut and overall wellbeing. Making these lifestyle changes can improve the effectiveness of probiotics and support your digestive health in the long term.

FAQs

1. Why do cardiologists warn against probiotics?

 Cardiologists usually warn against probiotics for people with significantly weakened immune systems, like those with serious illnesses. A compromised immune system may increase your risk of side effects in some cases. They may also be concerned about unregulated supplements that don’t have enough scientific proof. If you have health issues, it’s always best to check with your doctor before taking probiotics.

2. What stops probiotics from working?

Probiotics may not work well if they are not stored properly, if they don’t survive stomach acid, or if your diet lacks the right nutrients to support them. Taking antibiotics or eating too much processed food can also reduce their effectiveness.

3. Should probiotics be taken with or without food?

Most probiotics work better when taken with food because food helps protect them from stomach acid so they can reach the gut alive. However, always read the label on your probiotic supplement to check the best way to take it.

4. Are all probiotic supplements the same?

No, different probiotics have different benefits. Some are better for digestion, while others may support immunity or skin health. Always choose a probiotic supplement that contains well-researched strains, and look for products tested for quality and safety.

References

1. Mazziotta, Chiara, et al. ‘Probiotics Mechanism of Action on Immune Cells and Beneficial Effects on Human Health’. Cells, vol. 12, no. 1, Jan. 2023, p. 184. www.mdpi.com, https://doi.org/10.3390/cells12010184.

2. Mari, Amir, et al. ‘The Evolving Role of Gut Microbiota in the Management of Irritable Bowel Syndrome: An Overview of the Current Knowledge’. Journal of Clinical Medicine, vol. 9, no. 3, Mar. 2020, p. 685. PubMed Central, https://doi.org/10.3390/jcm9030685.

3. Zhang, Chengcheng, et al. ‘Meta-Analysis of Randomized Controlled Trials of the Effects of Probiotics on Functional Constipation in Adults’. Clinical Nutrition, vol. 39, no. 10, Oct. 2020, pp. 2960–69. ScienceDirect, https://doi.org/10.1016/j.clnu.2020.01.005.

4. Eslami, M., et al. ‘Probiotics Function and Modulation of the Immune System in Allergic Diseases’. Allergologia et Immunopathologia, vol. 48, no. 6, Nov. 2020, pp. 771–88. ScienceDirect, https://doi.org/10.1016/j.aller.2020.04.005.

5. Mirashrafi, Shahrzad, et al. ‘The Efficacy of Probiotics on Virus Titres and Antibody Production in Virus Diseases: A Systematic Review on Recent Evidence for COVID-19 Treatment’. Clinical Nutrition ESPEN, vol. 46, Dec. 2021, pp. 1–8. ScienceDirect, https://doi.org/10.1016/j.clnesp.2021.10.016.

6. Bistas, Karlyle G., and Jean Paul Tabet. ‘The Benefits of Prebiotics and Probiotics on Mental Health’. Cureus, vol. 15, no. 8, p. e43217. PubMed Central, https://doi.org/10.7759/cureus.43217. Accessed 20 Feb. 2025.

7. Marotta, Angela, et al. ‘Effects of Probiotics on Cognitive Reactivity, Mood, and Sleep Quality’. Frontiers in Psychiatry, vol. 10, Mar. 2019, p. 164. PubMed Central, https://doi.org/10.3389/fpsyt.2019.00164.

8. Kim, Chong-Su, et al. ‘Probiotic Supplementation Improves Cognitive Function and Mood with Changes in Gut Microbiota in Community-Dwelling Older Adults: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial’. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, vol. 76, no. 1, Apr. 2020, pp. 32–40. PubMed Central, https://doi.org/10.1093/gerona/glaa090.

9. Nicol, Marion, et al. ‘Lactobacillus Salivarius and Lactobacillus Gasseri Supplementation Reduces Stress‐induced Sugar Craving in Mice’. European Eating Disorders Review, vol. 32, no. 6, Nov. 2024, pp. 1041–54. DOI.org (Crossref), https://doi.org/10.1002/erv.3004.

10. Narmaki, Elham, et al. ‘The Combined Effects of Probiotics and Restricted Calorie Diet on the Anthropometric Indices, Eating Behavior, and Hormone Levels of Obese Women with Food Addiction : A Randomized Clinical Trial’. Nutritional Neuroscience, vol. 25, no. 5, May 2022, pp. 963–75. DOI.org (Crossref), https://doi.org/10.1080/1028415X.2020.1826763.

11. Goodman, Clare, et al. ‘Probiotics for the Prevention of Antibiotic-Associated Diarrhoea: A Systematic Review and Meta-Analysis’. BMJ Open, vol. 11, no. 8, Aug. 2021, p. e043054. bmjopen.bmj.com, https://doi.org/10.1136/bmjopen-2020-043054.

12. Teng, Y., Huang, Y., Danfeng, X., Tao, X., & Fan, Y. (2022). The Role of Probiotics in Skin Photoaging and Related Mechanisms: A Review. Clinical, Cosmetic and Investigational Dermatology, 15, 2455–2464. https://doi.org/10.2147/CCID.S388954

13. Y. Yu, S. Dunaway, J. Champer, J. Kim, A. Alikhan, Changing our microbiome: probiotics in dermatology, British Journal of Dermatology, Volume 182, Issue 1, 1 January 2020, Pages 39–46, https://doi.org/10.1111/bjd.18088

14. Bhutto, Rizwan Ahmed, et al. ‘Recent Trends in Co-Encapsulation of Probiotics with Prebiotics and Their Applications in the Food Industry’. Trends in Food Science & Technology, vol. 156, Feb. 2025, p. 104829. ScienceDirect, https://doi.org/10.1016/j.tifs.2024.104829.