What is Glutathione?
Glutathione is known as a ‘master antioxidant’, providing the body with powerful immune support. It is synthesized in the liver from three amino acids - glutamic acid, glycine and cysteine - and is used by every single cell in the body.
The active form of glutathione is known as 'reduced glutathione' (GSH), which has been proven to help neutralize free radicals, to offer powerful support for the immune system, and to combat damaging oxidative stress in the body.
It has also been shown to encourage a healthy balanced gut microbiome, keeping your gut health in peak condition.
Unfortunately, glutathione concentration can be damaged by toxins, age, stress, poor nutrition and more, which is why you may want to supplement or follow a specialised diet to increase your levels. L glutathione is a common supplement form used to support overall wellness.
Low glutathione levels have been linked to an increased risk of arthritis, cancer, cardiovascular disease, diabetes, gut issues, and more, so this isn’t something you should ignore. (1, 2)
Before we look at how glutathione helps gut health, it’s important we understand just how important our gut microbiome is in the first place….
Key Takeaways
- Glutathione is the body’s master antioxidant — crucial for immune defense, detoxification, and maintaining a balanced gut microbiome.
- Low glutathione levels can increase oxidative stress, inflammation, and gut permeability (“leaky gut”).
- Supplementing with bioavailable glutathione (like Setria® Glutathione) supports gut barrier integrity, microbiome balance, and overall digestive wellness.
- A nutrient-rich diet — especially one high in sulfur-rich foods — can naturally enhance glutathione levels.
- Combining Performance Lab Immune (for glutathione and immune support) with Performance Lab Prebiotic (for gut microbiome balance) offers comprehensive digestive protection. Alternatively, either one would be a great choice.
What is the Gut Microbiome?
When we discuss the gut microbiome, we're essentially talking about the gastrointestinal tract (GI tract), in particular the intestines.
In essence, the gut microbiome is a microscopic world inside our intestines. It is host to trillions of microorganisms - we're talking bacteria, fungi, viruses and even parasites (and yes, I know that last one doesn't sound so nice!).
We receive our first gut microbes as babies and our diet and environment adds new ones after that - though environmental exposure can also sometimes harm the gut and reduce the number of microbes.
Balance Needed
It's important to realise that we need both beneficial and harmful bacteria to keep our GI tract working properly, which is why balance is so important.
Gut microbiota can produce short-chain fatty acids, which are beneficial for gut health and may help regulate metabolic processes.
Why is our Gut Microbiome So Important?
It may help to think of our gut microbiome as a wild garden that provides us with natural medicines and foods. We live in symbiosis with the microorganisms within it: we provide them with a 'home' and in return they protect us from harmful bacteria.
But like any garden, if the soil is polluted or if weeds run rampant, it throws the whole ecosystem out of whack (technical term), and that has implications for your digestive and overall health.
That's because the gut is heavily interwoven with our body's immune system.
Immune Health Starts with the Gut
70% of our immune system is located in the gut, with immune cells directly liaising with the microbiome.
“The microbiome and the immune system are critically intertwined. What’s present in the gut determines what education immune cells get” says Jonathan Jacobs, MD, PhD, Professor of Digestive Diseases, David Geffen School of Medicine, UCLA.
Hopefully now you can understand the importance of gut health for the entire body. (3, 4)
How Can Glutathione Support Gut Health?
Now that we know why it’s so important to keep our gut healthy, let’s examine how glutathione can help.
Glutathione supplementation has demonstrated beneficial effects on gut health by reducing oxidative stress, improving gut microbiota composition, and supporting overall digestive function.
Let's examine that some more...
Reducing Oxidative Stress in the Gastrointestinal Tract
Oxidative stress occurs when there aren't enough antioxidants to tackle the free radicals that can cause DNA and tissue damage, inflammation and more. Oxidative stress has been linked to numerous diseases and conditions.
Glutathione is the primary antioxidant in our GI tract, and it can:
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Neutralize free radicals directly
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Encourage other antioxidants such as vitamins C and E to perform their functions well. (5-8)
Crucial Role in Decreasing Inflammation
As part of its role as an immune booster, glutathione not only supports immune cells but it also helps to control inflammatory cytokines - the signalling proteins that encourage inflammation in response to a threat.
Unfortunately, these cytokines can be a bit trigger happy, creating more inflammation than necessary which can also damage cells.
Being able to control them and reduce inflammation - while still allowing immune defenses to fight when necessary - is a huge advantage, courtesy of glutathione. (9-11)
Strengthens the Lining of the Gut
There are numerous studies that demonstrate that adequate levels of glutathione in the body helps to heal, strengthen and regenerate the cells along the gut lining.
Mucosal cells, which make up the gut lining, play a key role by producing glutathione (GSH), which is essential for maintaining gut barrier integrity and protecting against damage. Cysteine availability determines or limits this synthesis.
Why is the Gut Lining so Important?
The gut lining is a crucial aspect of our immune system as it acts as a barrier to bacteria and other toxins, preventing them from crossing from the gut.
Glutathione supplements or supplementation may help to minimize intestinal atrophy, again because of the antioxidant's power to tackle oxidative stress.
This, in turn, should help boost absorption of nutrients. It may also help to prevent ‘Leaky Gut’ - when the lining of the gut becomes so porous that it potentially allows toxins to cross into the bloodstream.
While ‘leaky gut’ isn’t a technical condition or diagnosis, studies have shown that people with gastrointestinal problems have a more porous intestinal lining that lets larger molecules through. More research is welcome on this. (12-15)
Detoxifies and Balances the Gut Microbiome
As a result of all the above, glutathione is recognized as helping to detoxify the intestines, as well as the whole body via detox pathways in the liver. In addition, studies have shown that it can also balance the gut microbiome.
Clinical trial: In one study of Indian diabetic individuals with type two diabetes, oral supplementation of glutathione (GSH) was administered for six months. Long term GSH supplementation led to notable changes in the diabetic gut microbiome.
Analysis of the gut microbiome revealed beneficial bacteria was significantly enriched, while the bad bacteria significantly decreased. (16)
"Data clearly demonstrate that GSH supplementation along with antidiabetic treatment helps restore the gut microbiome by enriching beneficial bacteria of healthy gut and reducing significantly the load of pathogenic bacteria" - study authors.
TIP: For an extra boost, a quality prebiotic can also support gut balance. We recommend Performance Lab Prebiotic.
Shop Performance Lab® Prebiotic
Factors that Affect Glutathione Levels
Glutathione levels in the body are influenced by a variety of lifestyle and environmental factors, such as...
A Healthy Diet for a Healthy Gut
What you eat plays a major role: a diet rich in colorful fruits, leafy greens, and high-quality proteins provides the building blocks your body needs to produce glutathione. Citrus fruits are also rich in vitamin C, which can help regenerate glutathione.
Increased consumption of fruits, vegetables, and whole grains can support the growth of beneficial gut bacteria. Foods high in antioxidants, such as berries and other fruits, can also help reduce oxidative stress and promote immune function.
On the other hand, a diet high in processed foods can deplete your glutathione stores, making it harder for your body to fight off oxidative stress and inflammation.
Gluten Free Diet
Gluten-free diets may be beneficial for anyone with gut health issues, such as celiac disease or non-celiac gluten sensitivity.
Inflammation
Chronic inflammation, metabolic syndrome, and liver disease can also lower glutathione levels (GSH levels), leaving your body’s cells more vulnerable to damage.
Toxins and Pollutants
Environmental toxins and pollutants - think cigarette smoke, heavy metals, and certain chemicals - can further sap your glutathione reserves, making it even more important to minimize exposure whenever possible.
Our Recommendation
If you’re looking to maintain optimal glutathione levels, glutathione supplements or precursors like N-acetyl cysteine (NAC) can help support the body’s own production. We recommend Performance Lab Immune — it delivers Setria® Glutathione in a highly bioavailable form for effective antioxidant support.
It’s always wise to consult with a healthcare provider before starting any new supplement, especially if you have underlying health conditions.
By focusing on a nutrient-rich diet, reducing processed foods, and supporting your body’s natural detoxification processes, you can help keep your glutathione levels - and your gut health - in top shape.
Glucose Metabolism
Note that glucose is the primary fuel for glutathione synthesis. Too high glucose levels, however, may interfere with glutathione creation, potentially leading to oxidative stress that can contribute to diabetes.
Implications of Glutathione Deficiency
A glutathione deficiency has been linked to several digestive-related conditions, such as leaky gut (mentioned above) as well as gut dysbiosis and chronic inflammation.
Gut Dysbiosis
Gut dysbiosis refers to an unhealthy or unbalanced gut microbiome. Essentially, your gut may have lost beneficial bacteria, be overrun with bad bacteria, or may lack bacteria diversity.
Diversity is important, consider how gardens thrive when plants can cross-pollinate or nourish each other.
Dysbiosis may cause cramps, constipation, diarrhea, food intolerance, bloating, inflammation, and more. It also leaves you vulnerable to disease-causing bacteria, and increases the risk of conditions such as Irritable Bowel Syndrome (IBS), Inflammatory Bowel Disease (IBD), obesity, diabetes, cardiovascular issues, cancer and more. (17)
Irritable Bowel Syndrome (IBS)
Clinical trials have found a link between Irritable Bowel Syndrome (IBS), oxidative stress and glutathione.
IBS tissue samples show a lower GR activity than normal colon tissue. Allow me to explain what that means...
GR stands for glutathione reductase and it's an enzyme that converts oxidized glutathione into a more active, bioavailable version of glutathione, known as 'reduced glutathione'. This is essentially the version of glutathione that does all the work.
The suggestion is that reduced GR activity and therefore less 'reduced glutathione' may be implicated in Irritable Bowel Syndrome - possibly because it has less defenses against free radicals, the cause of oxidative stress. (18)
Inflammatory Bowel Diseases
Not to be confused with IBS, Inflammatory Bowel Disease (IBD) can cause inflammation and permanent harm to the colon.
Studies have shown that glutathione depletion is associated with chronic inflammatory disorders of the colon, such as ulcerative colitis. (19, 20)
Likewise, biopsies from Crohn’s patients showed much lower total glutathione levels compared to healthy controls. (21)
So far researchers have stopped short of labelling glutathione deficiency as a sole cause of IBD, but they do suggest it's a likely contributing factor. The good news is that studies have also shown that glutathione supplements may help to reverse some of the damage. As may prebiotics or postbiotics. (22)
Best Glutathione Supplements (GSH Supplementation)
You can find many different forms of glutathione supplementation - in tablet form, sublingual, liquid, liposomal, and even IV injections. Inhaled glutathione is another form, but it may pose risks for individuals with asthma and should be used with caution.
Warning
The FDA does not approve glutathione injections for any purpose. Unregulated injections may cause organ damage.
The problem with most of these other forms is that the body doesn’t absorb glutathione all that well. Luckily, there’s an exception - Setria Glutathione, a patented form of glutathione that is deliberately made to be easy for the body to absorb.
A six-month trial at Penn State University proved that Setria Glutathione supplements raised blood and cell glutathione after one, three and six months. The trial also saw a reduction in oxidative stress, plus Natural Killer cells (NK cells) were twice as effective at targeting infections after supplementation with Setria Glutathione. (23)
You’ll find 250mg of Setria Glutathione inside Performance Lab Immune.
Even better, Immune also contains LC-Plasma, a probiotic that could potentially help to restore the balance of ‘good bacteria’ in the gut - as well as activating five different types of immune cells.
Strong immunity starts in the gut, which is why Performance Lab Immune combines an impressive probiotic and a potent antioxidant to help you keep your gut health in tip top shape.
Best Prebiotic For Gut Health
For premium gut health support, you can't beat Performance Lab Prebiotic. It uses research-backed Inulin-FOS prebiotic to help boost the healthy Bifidobacterium probiotics in the gut.
I’ve improved my gut health exponentially. Can’t recommend them enough.Josh S
To use our garden analogy again, the prebiotic acts as fertiliser while the probiotics are the healthy seeds that grow from it. Bifidobacterium probiotics help to tackle bad bacteria and boost the immune system, as well as potentially boosting the absorption of nutrients.
Research has shown that Inulin-FOS fiber can increase Bifidobacteria distribution in the gut from 20% to 71%
Take Home Thoughts
An unhealthy gut impacts more than just the digestive system; its effects can be felt as far away as the brain, heart, liver, kidneys, and more. Given that the majority of immune cells reside in the gut, keeping it healthy is the first step to a strong immune system.
Glutathione is one way to do that, especially in its highly bioavailable form of Setria Glutathione. It's an important antioxidant that helps to tackle oxidative stress and inflammation, and helps to strengthen and balance our gut microbiome. We recommend Performance Lab Immune for that.
A powerful prebiotic can also be beneficial for gut health, such as Performance Lab Prebiotic.
We also recommend a balanced diet full of fruit and vegetables, particularly sulfur-rich foods such as broccoli, kale, mushrooms, egg, meat, fish, garlic, and onions. These foods may increase glutathione levels in the body naturally.
References
- Townsend, D. M., Tew, K. D., & Tapiero, H. (2003). The importance of glutathione in human disease. Biomedicine & Pharmacotherapy, 57(3–4), 145–155.
- Julius, M., Lang, C. A., Gleiberman, L., Harburg, E., DiFranceisco, W., & Schork, A. (1994). Glutathione and morbidity in a community-based sample of elderly. Journal of Clinical Epidemiology, 47(9), 1021–1026.
- UCLA Health. If you want to boost immunity, look to the gut. https://www.uclahealth.org/news/article/want-to-boost-immunity-look-to-the-gut
- Cleveland Clinic. Gut Microbiome. https://my.clevelandclinic.org/health/body/25201-gut-microbiome
- Loguercio, C., & Di Pierro, M. (1999). The role of glutathione in the gastrointestinal tract: a review. Italian Journal of Gastroenterology and Hepatology, 31(5), 401–407.
- Uttara, B., Singh, A. V., Zamboni, P., & Mahajan, R. T. (2009). Oxidative stress and neurodegenerative diseases: a review of upstream and downstream antioxidant therapeutic options. Current Neuropharmacology, 7(1), 65–74. https://doi.org/10.2174/157015909787602823
- Biswas, P., Dellanoce, C., Vezzoli, A., Mrakic-Sposta, S., Malnati, M., Beretta, A., & Accinni, R. (2020). Antioxidant activity with increased endogenous levels of vitamin C, E, and A following dietary supplementation with a combination of glutathione and resveratrol precursors. Nutrients, 12(11), 3224.
- Hayes, J. D., & McLellan, L. I. (1999). Glutathione and glutathione-dependent enzymes represent a co-ordinately regulated defence against oxidative stress. Free Radical Research, 31(4), 273–300. https://doi.org/10.1080/10715769900300851
- Allen, M., Bailey, C., Cahatol, I., Dodge, L., Yim, J., Kassissa, C., … Venketaraman, V. (2015). Mechanisms of control of Mycobacterium tuberculosis by NK cells: Role of glutathione. Frontiers in Immunology, 6, 508.
- Perricone, C., De Carolis, C., & Perricone, R. (2009). Glutathione: A key player in autoimmunity. Autoimmunity Reviews, 8(8), 697–701.
- Lin, N., Erdos, T., Louie, C., Desai, R., Lin, N., Ayzenberg, G., & Venketaraman, V. (2024). The role of glutathione in the management of cell-mediated immune responses in individuals with HIV. International Journal of Molecular Sciences, 25(5), 2952.
- Kelly, N., Friend, K., Boyle, P., Zhang, X. R., Wong, C., Hackam, D. J., Zamora, R., Ford, H. R., & Upperman, J. S. (2004). The role of the glutathione antioxidant system in gut barrier failure in a rodent model of experimental necrotizing enterocolitis. Surgery, 136(3), 557–566. https://doi.org/10.1016/j.surg.2004.05.034
- Cleveland Clinic. Leaky Gut Syndrome. https://my.clevelandclinic.org/health/diseases/22724-leaky-gut-syndrome
- Uchida, H., Nakajima, Y., Ohtake, K., Ito, J., Morita, M., Kamimura, A., & Kobayashi, J. (2017). Protective effects of oral glutathione on fasting-induced intestinal atrophy through oxidative stress. World Journal of Gastroenterology, 23(36), 6650–6664. doi:10.3748/wjg.v23.i36.6650
- Mårtensson, J., Jain, A., & Meister, A. (1990). Glutathione is required for intestinal function. Proceedings of the National Academy of Sciences of the United States of America, 87(5), 1715–1719. https://doi.org/10.1073/pnas.87.5.1715
- Gaike, A. H., Kalamkar, S. D., Gajjar, V., Divate, U., Karandikar-Iyer, S., Goel, P., Shouche, Y. S., & Ghaskadbi, S. S. (2023). Effect of long-term oral glutathione supplementation on gut microbiome of type 2 diabetic individuals. FEMS Microbiology Letters, 370, fnad116. https://doi.org/10.1093/femsle/fnad116
- WebMD. What Is Dysbiosis? https://www.webmd.com/digestive-disorders/what-is-dysbiosis
- Lorestani, S., Bahari, A., Asadi, M., & Zahedi Avval, F. (2021). Evaluation of glutathione reductase activity in colon tissue of patients with irritable bowel syndrome. Hormone Molecular Biology and Clinical Investigation, 42(2), 195–198.
- Kim, J. H., Ahn, J. B., Kim, D. H., Kim, S., Ma, H. W., Che, X., Seo, D. H., Kim, T. I., Kim, W. H., Cheon, J. H., & Kim, S. W. (2020). Glutathione S-transferase theta 1 protects against colitis through goblet cell differentiation via interleukin-22. FASEB Journal, 34(2), 3289–3304.
- Ruan, E. A., Rao, S., Burdick, J. S., Stryker, S. J., Telford, G. L., Otterson, M. F., Opara, E. C., & Koch, T. R. (1997). Glutathione levels in chronic inflammatory disorders of the human colon. Nutrition Research, 17(3), 463–473.
- Pinto, M. A., Lopes, M. S., Bastos, S. T., Reigada, C. L., Dantas, R. F., Neto, J. C., Luna, A. S., Madi, K., Nunes, T., & Zaltman, C. (2013). Does active Crohn's disease have decreased intestinal antioxidant capacity? Journal of Crohn's & Colitis, 7(9), e358–e366. https://doi.org/10.1016/j.crohns.2013.02.010
- Loguercio, C., D'Argenio, G., Delle Cave, M., Cosenza, V., Della Valle, N., Mazzacca, G., & Del Vecchio Blanco, C. (2003). Glutathione supplementation improves oxidative damage in experimental colitis. Digestive and Liver Disease, 35(9), 635–641. https://doi.org/10.1016/s1590-8658(03)00379-7
- Richie, J. P., Jr, Nichenametla, S., Neidig, W., Calcagnotto, A., Haley, J. S., Schell, T. D., & Muscat, J. E. (2015). Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. European Journal of Nutrition, 54(2), 251–263.
