Natural Immune Boosters: Evidence-Based Ways to Support Immunity

Natural immune boosters are widely discussed, yet often misunderstood. The immune system does not work like an on/off switch, and it is not something you can strengthen overnight with a single food or supplement. What research does support is a range of natural compounds that help fine-tune how immune cells develop, communicate, and respond over time. These substances mostly come from familiar foods, herbs, and well-studied bioactive extracts rather than exotic miracle ingredients. This article focuses on what is supported by evidence and what is not, so you can make informed choices about supporting your immune health.

Why “Immune Booster” Is the Wrong Word (And What to Use Instead)

When scientists talk about immunity, they rarely use the word “boost”. And that difference matters. Your immune system is highly complex. It has multiple layers, including innate immunity, which responds quickly to potential threats, and adaptive immunity, which builds targeted, long-term protection. 

These systems must work together in a coordinated way and simply ramping everything up doesn’t help. In fact, an overactive immune system contributes to allergies, chronic inflammation, and autoimmune diseases (1,2).

Because of this, researchers use a more precise term: immunomodulation. This refers to regulating immune responses rather than amplifying them. The goal is balance and coordination, not constant activation (3,4).

In practical terms, this means that well-studied natural compounds do not “supercharge” the immune system. Instead, they help it respond appropriately: stronger when facing a real threat, and calmer when there’s nothing to fight.

For clarity in this article, we’ll use “natural immune boosters” in this balanced sense: natural foods, nutrients, and compounds that support normal immune function, particularly when your system is under stress, ageing, or running low on key nutrients.

The Building Blocks: Vitamins and Minerals Your Immune Cells Actually Need

Before we talk about special compounds or trendy supplements, let’s get a basic point straight. Your immune cells, including white blood cells, antibodies, and everything else, are made of the same building blocks as the rest of your body: proteins, fats, and micronutrients.

Without adequate vitamins and minerals, your immune system simply can’t function. This isn’t about dramatizing the issue. It’s simply biology. Deficiency here shows up as increased susceptibility to colds and respiratory infections, delayed recovery, and a slower vaccine response (5). So which nutrients actually have strong scientific backing when it comes to immune function?

Vitamin C

Vitamin C does two things: it boosts the production and activity of white blood cells, and it protects those cells from oxidative damage through antioxidant action (6,7). It’s not magic, but it’s fundamental.

• Dietary sources: citrus fruits, kiwi, berries, broccoli, cabbage, kale, peppers.

Vitamin D

This one deserves special attention because many people are deficient, especially in the winter months. Vitamin D helps immune cells activate correctly and supports your defence against infections (8). Some research suggests it may reduce the severity of respiratory infections, though the effect isn’t universal (👉 See BioBran Plus D3).

• sources: skin synthesis via sunlight exposure; dietary sources include oily fish, eggs, and fortified foods; supplements are commonly used, especially during winter months

Vitamin E (nuts, seeds, plant oils, leafy greens)

This vitamin is an antioxidant that specifically protects immune cell membranes and supports the function of T cells, which are key players in adaptive immunity (7). 

• Dietary sources: primarily plant-based foods, especially edible oils (such as olive, rapeseed, sunflower, palm, and nut oils), nuts and seeds, whole grains, leafy green vegetables, and fruits like avocado.

Zinc, selenium, magnesium, and iron 

These micronutrients are required for immune cell production and antibody responses. The link between deficiency and impaired immunity is direct and well-documented (9,10).  

• Dietary sources: zinc and iron are abundant in cereals, meat, soy products, and fish, while selenium is more readily absorbed from grains such as corn and wheat; magnesium is commonly found in grains, potatoes, and vegetables, with plant-based foods being the main sources of all four minerals.

In summary: Vitamins and minerals are not exciting or novel, but they’re non-negotiable. Adequate intake supports smooth immune function. Deficiency increases your susceptibility to infections (11). If you’re eating a varied, whole-food diet with plenty of plant foods, you’re likely covering your bases. If you’re not, a nutritional gap here will undermine everything else you try to do.

The Gut Connection: Why Probiotics Matter More Than You Think

About 70 percent of your immune system lives in and around your gut. This is not a metaphor but a literal description of where most immune cells reside and where much of immune decision-making happens (12).

That is why fermented foods such as yoghurt, kefir, kimchi, sauerkraut, and other traditionally fermented products are often considered natural immune boosters. They introduce and support beneficial bacteria that do not simply remain passive in the gut. Here is what these bacteria do:

• They produce short chain fatty acids that help regulate inflammation and strengthen the gut barrier, reducing the risk of inappropriate immune activation (13).
• They influence antibody production, the body’s way of remembering threats, and support natural killer cell activity, one of the immune system’s most powerful tools (14).

Worth knowing: Research indicates that probiotics can modestly reduce some gastrointestinal and respiratory infections (15). Although this does not replace vaccination or good hygiene, probiotics are a supporting player with genuine science behind them. In practical terms, this means including fermented foods regularly if you tolerate them well. You do not need supplements for this. Real food works.

Medicinal Mushrooms and Immunity

This is where we move past the basics your body simply can’t do without and look at compounds that actively shape how your immune system behaves.

Mushrooms contain specific polysaccharides, particularly β-glucans, that have strong immunomodulatory effects (16,17).  What makes them distinctive is that they do not merely reduce inflammation or neutralize free radicals. 

Instead, they interact directly with innate immune cells such as macrophages and natural killer (NK) cells, effectively “training” them to recognise and respond to threats more efficiently. It’s closer to a coaching effect than a stimulation effect, and your immune system becomes sharper and more coordinated.

What mushrooms are best for immunity? The strongest evidence exists for varieties naturally rich in β-glucans, especially shiitake (Lentinula edodes) and oyster types (Pleurotus species). These mushrooms are noted for their anti-inflammatory and immunomodulatory activities, supporting their traditional use as natural immune boosters (18).

Arabinoxylans: A Different Category of Natural Immune Modulators

Among natural compounds, arabinoxylans represent something distinct. Found primarily in cereal brans (especially rice bran), they are complex polysaccharides that interact with immune regulation in ways similar to mushroom compounds, but with their own particular strengths (19,20). 

Related reading:

• Natural Immunomodulators: How Plant Compounds Support Immunity? – doplňte url
• How Do Immunomodulators Work: The Secret Conversation Inside Your Body
• Immunomodulators: Natural Allies of Our Immune System

One well-studied example is BioBran MGN-3, a rice bran-derived arabinoxylan that has been enzymatically modified using enzymes from shiitake mushrooms. This modification makes it more bioavailable, so your body can actually use it.

Clinical studies show that BioBran enhances the activity of natural killer cells, dendritic cells, and T cells, particularly in older adults and people with weakened immune responses (21,22).  What’s important to note is that the research describes it as supportive and regulatory, not as an aggressive immune stimulant. Like mushroom polysaccharides, it’s about balance and coordination, not overdrive.

Immune Modulation Rather Than Stimulation: The reason BioBran appears in the literature separately from general “immune boosters” is that it occupies a precise niche: targeted immune modulation for aging immunity and specific immune challenges. If you’re interested in moving beyond general dietary support toward more active immune regulation, this is what the science points to.

Boosting immunity during flu season is like a puzzle with many small, interconnected pieces. Researchers continue to explore how daily habits and underlying immune factors shape our vulnerability to infection. These insights help explain why some people stay well while others fall ill. And they offer a clearer, more grounded view of what effective flu prevention can look like.

Why Flu Prevention Needs More Than One Strategy

When winter arrives, so does the annual question: how do you stay healthy when everyone around you seems to be sniffling and coughing? The answer lies partly in your immune system’s remarkable ability to defend you from viral invaders. 

But here’s the thing: your immune system isn’t like a light switch you can simply turn on or off. It’s more like a sophisticated security system that requires proper maintenance and support to function at its best. Scientific research has identified three main pillars for effective influenza prevention: 

• annual vaccination
• antiviral therapy
• immune system strengthening through specific nutrients and plant-based compounds 

Of these, vaccination remains the gold standard. Updated yearly to match circulating virus strains, the seasonal flu vaccine is recommended for all individuals aged six months and older [1,2,3]. 

However, even vaccines aren’t perfect. Sometimes viral mutations reduce their effectiveness in certain seasons which is precisely why a multi-layered approach to flu prevention makes such good sense [4].

Natural immune boosters for cold and flu supported by research

Only a few groups of natural compounds show meaningful effects in cold and flu prevention. These include:

• vitamins and minerals such as vitamin C, vitamin D and zinc
• herbal preparations including Echinacea, garlic, ginseng and thyme
• probiotics that influence gut-mediated immune responses
• polysaccharides and natural immunomodulators such as arabinoxylans
• plant phytochemicals like green tea catechins and flavonoids

These categories differ in strength and type of evidence, which the following sections explore in more detail.

Vitamin C – popular but limited benefits

Vitamin C supplements show only slight benefits for preventing colds once you are already at risk [5]. This often surprises people because high dose vitamin C has a strong cultural reputation as an immunity essential. However, studies consistently show that unless you are under extreme physical stress, such as an athlete running marathons in winter, supplementation will not significantly reduce the likelihood of catching a cold or flu.

Even so, vitamin C remains important for immune function because it contributes to antioxidant defence and helps immune cells operate efficiently. The practical takeaway is simple. Focus on meeting your daily needs through a diet rather than relying on vitamin C supplements for real flu protection. Citrus fruits, berries and peppers are reliable sources that help maintain baseline immune health [6].

People also read:

• Natural Immunomodulators: How Plant Compounds Support Immunity
• How Do Immunomodulators Work: The Secret Conversation Inside Your Body
• Immunomodulators: Natural Allies of Our Immune System

Zinc – the natural cold-shortener

Zinc presents a very different picture. When taken within the first 24 hours of cold symptoms, zinc lozenges can shorten illness duration and reduce overall severity. A meta-analysis showed that zinc reduced the length of a cold by roughly two days, which is a meaningful difference when you are already feeling unwell [7]. The key parameters for zinc supplementation:

• daily zinc doses below 75 mg show no effect
• zinc acetate formulations show the strongest evidence
• start within 24 hours of symptom onset
• lozenge form appears more effective than tablets or syrup

Importantly, zinc is most useful as a treatment, not as prevention. Data on taking zinc before you get sick remain inconsistent [8].

Vitamin D and flu – the immunity nutrient that actually matters

Vitamin D is one of the few nutrients with clear and consistent evidence for reducing respiratory infections, especially if your baseline levels tend to run low [9]. The practical implications:

• individuals who are very vitamin D deficient (with levels below 25 nmol/L) benefit most from supplementation
• daily or weekly dosing appears more effective than occasional large doses
• standard recommendations suggest 1000–2000 IU daily for most adults
• testing your vitamin D level (25-hydroxyvitamin D blood test) can guide your approach
• many people, especially in northern climates during winter, are naturally vitamin D deficient

👉 See BioBran Plus D3

Herbal remedies for cold and flu

Herbal products represent perhaps the most misunderstood category of immune support. Traditional use does not guarantee efficacy, but some traditional plants do have genuine scientific backing. Well-studied plants relevant to respiratory infections:

• Echinacea may shorten cold duration and symptom severity, though results are mixed and depend on species and extract type [10]
• Garlic and aged garlic extract enhance natural killer cell activity and may reduce infection severity [11]
• North American ginseng shows potential for lowering the incidence of flu-like illnesses in high-risk populations [12]
• Thyme, peppermint and honeysuckle contain compounds with documented antiviral mechanisms [12]
• Green tea catechins may inhibit viral replication, though clinical trials remain inconsistent [13]

Probiotics and gut health in cold and flu prevention

Your gut is not just responsible for digestion. It contains roughly 70 percent of your immune system’s cells. The bacteria living in your gut essentially train your immune cells to respond more effectively to viral threats. Probiotics offer indirect yet valuable support for respiratory immunity by influencing the gut–immune axis. Key findings from research include [5,14]:

• Lactobacillus strains can reduce the frequency of upper respiratory infections 
• probiotics increase secretory IgA, a key class of antibodies involved in mucosal defence
• certain strains boost interferon gamma production, a key antiviral immune molecule
• benefits require consistent use, not occasional supplementation

Arabinoxylans as natural immunomodulators

Arabinoxylans are natural compounds found in cereal grains, particularly rice bran. They act as gentle immunomodulators that help boost the immune system without overstimulating it. Here is what scientific research on arabinoxylans suggests: 

• oral arabinoxylans can enhance the activity of macrophages and natural killer cells, making early antiviral responses more efficient [15]
• they influence both innate and adaptive immunity by promoting T and B cell activity (the cells responsible for your body’s long-term memory against pathogens) [16]
• they may reduce the incidence of common colds in older adults, with some evidence suggesting improved response to influenza vaccination [14]
• they drive shifts in gut microbiota composition that are associated with improved antiviral immune responses [17]

How to Prevent Flu and the Common Cold: A Realistic Layered Strategy

You cannot make your immune system invincible. What you can do is support its core functions with several complementary approaches. A realistic flu prevention plan has three layers:

Layer 1: The foundation

• annual flu vaccination from September to November
• consistent handwashing and respiratory etiquette
• avoiding close contact with sick individuals during peak season
• adequate sleep, since sleep deprivation directly weakens immune responses

Layer 2: Stronger evidence

• Vitamin D: 1000–2000 IU daily (more if clinically deficient)
• Zinc: keep lozenges on hand for use within 24 hours of symptom onset
• Aged garlic extract: helpful for those in high-risk groups or with frequent infections
• BioBran MGN-3: particularly relevant for older adults or people with weakened immune function (we recommend BioBran Plus D3)

Layer 3: Promising additions

• Probiotics: regular intake to maintain gut-mediated immunity
• Herbal blends: Echinacea, ginseng or polyherbal formulas if you prefer plant-based approaches
• Green tea: consistent consumption for catechins linked to antiviral activity

About the author: 

Maria Piknova, PhD, is a biochemist and science blogger specialising in microbiology and molecular biology. She is passionate about translating complex science into clear, evidence-based insights. [ORCID / LinkedIn]

Your body’s immune system is your frontline defence against infections and illness. When it functions properly, it protects you. But sometimes, whether from stress, age, or ongoing health challenges, it needs support to work optimally. That’s where natural immunomodulators come in. They’re plant compounds that help restore your immune response through multiple pathways at once, with lower toxicity and better tolerability for long-term use.

What Are Natural Immunomodulators? Understanding the basics

Natural immunomodulators are biological compounds found in plants, fungi, seeds, and grains that influence how your immune system functions. Unlike synthetic drugs that act very precisely on single immune targets and often produce strong systemic effects, natural immunomodulators help the body recognise and respond to challenges through several pathways at once. This broader action usually comes with lower toxicity and makes them suitable for long term use [1].

The Arsenal of Nature: Main Classes of Natural Immunomodulators 

Natural immunomodulators are not a single, uniform group. They belong to several distinct chemical classes, each operating through different mechanisms. This diversity is beneficial because these compounds can work together to address various types of threats. So, what are these classes, and how do they work?

Visual summary of seven chemical classes of natural immunomodulators and their core biological functions across immune pathways.

1. Polysaccharides: Direct Immune Activation

• Polysaccharides are long chains of sugar molecules linked together. They form the structural backbone of cell walls in fungi and the outer layers of cereal grains.
• Well‑known examples include arabinoxylans from rice (e.g. BioBran MGN-3) or wheat, beta‑glucans from mushrooms and yeast, and pectins from the cell walls of fruits. 
• These compounds boost the immune system by activating immune cells like macrophages, natural killer cells, and lymphocytes. They also help balance gut bacteria, which supports overall immunity [2].

👉 BioBran Plus D3 combines arabinoxylan from rice bran with brewer’s yeast and vitamin D. These added ingredients, including beta-glucans, selenium and chromium, help reinforce the immunomodulating effects of BioBran.

2. Polyphenols: The Inflammation Controllers

• Polyphenols are a large family of over 8,000 natural compounds found in many plant-based foods such as fruits, vegetables, tea, and wine [3].
• Examples include flavonoids like quercetin and epigallocatechin gallate (EGCG) from green tea, curcumin from turmeric, and resveratrol from red grapes.
• They reduce excessive inflammation and protect cells from oxidative stress caused by free radicals. This dual antioxidant and anti-inflammatory action helps the immune system respond effectively without overreacting or causing tissue damage [4].

3. Alkaloids: Cellular Immune Modulators

• Alkaloids are nitrogen-containing organic compounds synthesized by plants as part of their chemical defence system. They are found concentrated in seeds, roots, and leaves of medicinal plants.
• Common examples include berberine from barberry and Oregon grape, piperine from black pepper, caffeine from coffee and tea, and quinine from cinchona bark. These alkaloids have been used for centuries in traditional medicine systems across Asia, Africa, and South America [5]. 
• Alkaloids help your immune cells communicate and produce more protective compounds like interferons and antibodies. They also calm inflammation and feed beneficial bacteria in your gut, which strengthens your defences overall [6].

4. Terpenoids: The Aromatic Defenders

• Terpenoids are fragrant plant molecules that give herbs, fruits, and trees their characteristic aroma and taste. 
• Some of the most well-known immunomodulatory terpenoids include boswellic acids from Boswellia species, betulinic acid from birch, limonene from lemon, pinene from pine, and myrcene from hops.
• They regulate immunity by controlling cytokines, chemical messengers that balance inflammation and immune responses. Some compounds also increase white blood cells and activate broad immune actions, helping your body fight infections more effectively.

5. Glycosides, Saponins and Sterols: Multi-action molecules

• Glycosides combine sugars with other molecules, saponins are a specific type of glycosides with soap-like properties, and sterols are fat-like molecules important in cell membranes [7].
• Key examples include ginsenosides from ginseng, saponins from agave, and glycyrrhizin from licorice [8].
• These compounds modulate immunity by activating immune cells, boosting the production of protective molecules, and helping control inflammation to keep the immune system balanced and effective.

6. Vitamins and Minerals: Beyond Basic Nutrition

• Vitamins and minerals do more than just supply raw materials for your body to function. They also act as immunomodulators by fine-tuning immune activity.
• Key immunomodulatory micronutrients include vitamins C, D, and E. Among minerals, zinc, selenium, magnesium, copper, and iron play particularly important roles.
• They influence how immune cells function by regulating the production of signalling molecules and balancing inflammation. This helps the immune system respond properly to threats without overreacting, which is essential for preventing infections and autoimmune diseases.

7. Probiotics and prebiotics: Gut-Immune Allies

• Probiotics and prebiotics help shape how your immune system responds to threats by influencing the balance between friendly microbes and immune cells in the gut [9].
• Probiotics are live beneficial bacteria found in fermented foods like yoghurt, kefir, and sauerkraut. Prebiotics are plant fibres in foods like garlic, onions, and leeks that feed these good bacteria [10].
• Together, they support anti-inflammatory responses, strengthen the gut barrier, improve gut microbial diversity, and help prevent chronic inflammation and infections [11,12].

How Natural Immunomodulators Work

Arabinoxylans: Understanding a Specific Class

Among polysaccharides, arabinoxylans stand out. And for good reason. Research demonstrates they deliver both direct immune activation and broader metabolic benefits. You’ll find this specific type of polysaccharide fibre in rice bran, wheat, and rye.

What you need to know about arabinoxylans:

• They wake up your immune cells (like macrophages and natural killer cells), and help them communicate with each other to mount a stronger defence.
• They act as prebiotics, and increase the production of short-chain fatty acids, which reduce inflammation and support immune function.
• They show broader biological effects, including reduced oxidative stress when compared with other polysaccharides such as beta-glucans or inulin.
• They are considered safe for long-term use, with no known adverse effects at doses of around 2 to 3 g per day.

Clinical evidence: low dose, measurable outcomes

In a randomised clinical trial involving 80 older adults taking 500 mg of Biobran daily for three months, participants experienced lower incidence of influenza-like illness, together with increased natural killer cell activity, with no reported side effects [14]. A second study [15] in a geriatric population reported similar increases in NK activity after 30 days at the same dose.

Who is most likely to benefit from arabinoxylan supplements

• individuals with weakened immune function
• people experiencing chronic inflammation
• those with metabolic disorders or type 2 diabetes, where they support glucose and lipid regulation [16]. 
• older adults with reduced innate immune activity

Summary

Natural immunomodulators are evidence-based tools for immune support with documented safety advantages. When used consistently and in well-characterized forms supported by clinical research, they can meaningfully enhance immune capacity. Their primary advantage is supporting immunity through multiple pathways, while remaining gentle and well tolerated.

References

1. https://doi.org/10.1155/2023/7711297 
2. https://doi.org/10.3389/fimmu.2025.1640679 
3. https://doi.org/10.3390/nu10111618 
4. https://doi.org/10.1155/2018/1264074 
5. https://doi.org/10.1155/2020/1303524 
6. https://doi.org/10.2147/DDDT.S299120 
7. https://doi.org/10.1016/j.biopha.2020.110959 
8. https://doi.org/10.3390/molecules29010113 
9. https://doi.org/10.3389/fnut.2024.1355542 
10. https://doi.org/10.3748/wjg.v29.i14.2078 
11. https://doi.org/10.3389/fimmu.2021.578386 
12. https://doi.org/10.3389/fnut.2021.634897
13. https://doi.org/10.1016/j.carbpol.2015.11.068
14. https://doi.org/10.3390/nu13114133
15. https://doi.org/10.3892/etm.2018.5713 
16. https://doi.org/10.1016/j.foodchem.2021.131106 

About the author: 

Maria Piknova, PhD, is a biochemist and science blogger specialising in microbiology and molecular biology. She is passionate about translating complex science into clear, evidence-based insights. [ORCID / LinkedIn]

Immunomodulators are rewriting the rules of immune control. But how do they actually work? The mechanisms behind these agents could flip the switch between illness and resilience.

When Balance Breaks, Immunomodulators Step In

Every single day, your body is engaged in an invisible battle. Viruses are attempting to break in, bacteria are trying to establish outposts, and sometimes your own cells mutate and become a threat. Yet most of the time, you don’t notice anything happening at all. 

This remarkable silence is due to your immune system, a sophisticated network of cells and molecules working in perfect coordination. But what happens when this system starts to slow down or work inefficiently? This is where immunomodulators come into play. 

What are immunomodulators? They are biologically active substances that can adjust, enhance, or suppress the immune system’s activity to help your body maintain balance and fight diseases more effectively.

There are several types of immunomodulators, including both natural and synthetic compounds. Scientists classify them according to their origin, chemical structure, and the part of the immune system they influence. For a clear definition, classification, and examples, visit our main article Immunomodulators: Natural Allies of Our Immune System.  

How Does the Immune System Work?

To understand how immunomodulators work, you first need to grasp how your immune system operates. Think of it as two distinct security systems working in parallel, each with different strengths and response times.

Innate immunity is the body’s first defence against infections and threats. It uses various types of white blood cells such as macrophages, dendritic cells, natural killer cells, and other innate lymphoid cells to quickly recognise and attack invaders[1].

Adaptive immunity is slower,  but provides highly specific and long-lasting protection. This system requires training and education. It relies on specialised cells called B cells and T cells, which recognise unique features (antigens) of pathogens and remember them for faster responses in the future[2].

Table: Main characteristics of the innate and adaptive immune systems.

The two systems work together seamlessly. Innate immunity provides an immediate response, while also gathering intelligence about the threat. This intelligence gets passed to adaptive immunity, which then generates a targeted, long-lasting response.  

And what role do immunomodulators play in this complex story? Some modulate innate immunity, others affect adaptive immunity, and a few can influence both systems at once. They do so by targeting different immune cells and signalling pathways within each system.

What Is the Mechanism of Action of Immunomodulators?

Your immune cells don’t simply react to danger. They communicate through a sophisticated molecular language. Immunomodulators work by either mimicking this language or amplifying certain parts of the conversation. Their mechanisms of action are diverse and depend on the type of immunomodulator. The main modes of action are as follows[3]:  

1. Modulating immune cell activity – immunomodulators can either stimulate or suppress the activity of various immune cells, helping the body fight infections or cancer, or preventing overactive immune responses. For example, some natural immunomodulators affect macrophages and neutrophils, essentially giving these cells bigger appetites and better digestion.
2. Affecting signalling pathways – many immunomodulators enhance the production of molecules called cytokines. Cytokines are chemical messengers that tell immune cells how to behave, either ramping up or calming down the immune response.
3. Direct binding to cell surface receptors – think of receptors as mailboxes on the surface of immune cells used for communication between cells. When an immunomodulator delivers its “message” by binding to these mailboxes, it triggers a signalling cascade that can change how the immune cell reacts to future threats.
4. Regulating inflammation – many immunoactive compounds help control inflammation by either increasing or decreasing the production of inflammatory molecules, which is important in treating autoimmune diseases and allergies.
5. Promoting immune memory or tolerance – certain agents help the immune system remember past threats or teach it to ignore harmless substances (important in allergies, asthma and transplants).
6. Directly affecting disease processes – some synthetic or natural immunomodulators can stop the growth of cancer cells (inducing apoptosis – programmed cell death), prevent blood vessel formation in tumours, or help repair tissues by influencing immune responses.

Immunomodulators can act through several mechanisms, influencing how the immune system recognises, communicates, and responds to potential threats.   

Immunomodulators can act through several mechanisms, influencing how the immune system recognises, communicates, and responds to potential threats.

Arabinoxylans: Natural Immune Enhancers

Among all the immunomodulatory compounds, arabinoxylans have attracted particular scientific attention due to their ability to modulate both innate and adaptive immune responses. These natural immune enhancers are complex polysaccharides found in the outer layers of grain brans, particularly rice bran. 

Arabinoxylans exemplify how sophisticated natural immunomodulators engage multiple mechanisms simultaneously. Here’s what research tells us about arabinoxylan benefits and their mechanisms of action:

• They talk directly to immune cells. Arabinoxylans can interact with macrophages and dendritic cells in the gut, activating receptors such as Dectin-1. This helps trigger both innate and adaptive immune responses[4]. 
• They feed your microbiome. Acting as prebiotics, arabinoxylans serve as food for beneficial bacteria in the gut. These microbes, in turn, produce short-chain fatty acids and other metabolites that reduce inflammation and support immune balance[5].

What Is BioBran MGN-3 and How Does It Work?

BioBran, scientifically known as MGN-3, represents the pinnacle of modern use of arabinoxylans in medicine. It is a plant-derived immunomodulator made from rice bran that has been enzymatically modified using enzymes from shiitake mushrooms. 

Research[7] shows that BioBran arabinoxylan compound can enhance both innate and adaptive immune functions, especially in older adults and high-risk populations. It works by stimulating various immune cells, including natural killer cells, dendritic cells, and T cells. This stimulation leads to an improved ability to fight against viruses, bacteria and tumour (cancer) cells. Health benefits of BioBran according to clinical studies[8-12]:

• Improves quality of life. BioBran MGN-3 has been shown to enhance both physical and mental well-being in older adults, reducing pain, increasing energy and improving social functioning.
• Strengthens immune defence. It boosts the activity of natural killer cells, dendritic cells and T cells, helping the immune system respond more effectively and reducing the risk of flu-like illnesses, especially in the elderly.
• Supports cancer therapy. When used alongside conventional treatment, BioBran may strengthen immune responses, lessen chemotherapy side effects and potentially improve survival rates.
• Protects liver and brain health. BioBran has demonstrated protective effects on the liver and may help prevent damage while supporting healthy function. Research also suggests antioxidant and anti-ageing properties that could benefit brain health, though more human studies are needed.
• Shows antiviral potential. Early findings indicate BioBran may help the body combat viral infections, including SARS-CoV-2  (the virus that causes COVID-19), by boosting immune cell activity and lowering viral load in laboratory models.

BioBran MGN-3 Arabinoxylan Compound, a nutritional supplement produced from rice bran. Available in boxes of 30 or 105 sachets, or as 50 tablets.

The Future of Immune Health and Natural Modulation

Understanding how immunomodulators work reveals a profound truth about health: sometimes the most sophisticated solutions come from sources our ancestors already valued. Rice bran has been prized in traditional medicine for centuries, while shiitake mushrooms have long been consumed and respected for their nutritional and healing properties. 

Yet it has taken modern scientific tools to uncover how these traditional substances work at the molecular level. The growing body of evidence on immunomodulators shows that natural compounds can enhance multiple components of the immune system at once. Arabinoxylans and BioBran MGN-3 demonstrate how a deeper understanding of biological mechanisms can translate into practical strategies for maintaining immune health.

Frequently Asked Questions: How Immunomodulators Work

What are immunomodulators? – Immunomodulators are biologically active substances that adjust, enhance, or suppress the immune system’s activity to help the body maintain balance. Learn more about their definition, types, classification and examples in our main article Immunomodulators: Natural Allies of Our Immune System.

How do immunomodulators work? –  Immunomodulators influence the immune system in several ways. They can attach to receptors on immune cells, adjust the signals that control how these cells communicate (cytokines) and help manage inflammation or immune memory. These actions coordinate how the body recognises and responds to potential threats.

What does the term ‘immunomodulator’ mean? – The true meaning of immunomodulator lies in balance rather than strength. These substances help the immune system decide when to activate or rest, maintaining harmony instead of constant stimulation.

What are arabinoxylans? – Arabinoxylans are complex polysaccharides found in cereal brans such as rice and wheat. They act as natural immune enhancers, supporting both innate and adaptive immunity through direct effects on immune cells and by nourishing beneficial gut bacteria.

What is the difference between arabinoxylan fibre and arabinoxylan supplement? – Arabinoxylan fibre naturally occurs in whole grains and acts mainly as a prebiotic. Arabinoxylan supplements, such as BioBran, are concentrated or enzymatically modified forms designed to deliver higher, more bioactive doses with direct immunomodulatory effects.

What is BioBran and how does it support immunity? – BioBran MGN-3 is a natural immune product derived from rice bran and modified with shiitake mushroom enzymes. Studies show that it boosts natural killer (NK) cell activity and overall immune defence, making it one of the best-studied arabinoxylan-based supplements for immune health.

References

1. https://doi.org/10.1038/ni.3375
2. https://doi.org/10.1002/mco2.714
3. https://doi.org/10.1007/s44337-024-00029-3  
4. https://doi.org/10.1016/j.ijbiomac.2022.04.071
5. https://doi.org/10.1016/j.carbpol.2015.11.068 
6. https://doi.org/10.3389/fmicb.2016.00979
7. https://doi.org/10.3390/molecules28176313
8. https://doi.org/10.1007/s11136-019-02286-7
9. https://doi.org/10.1177/1534735417735379
10. https://doi.org/10.1016/j.biopha.2020.110064
11. https://doi.org/10.3390/nu17121993
12. https://doi.org/10.3390/nu16060881
13. Photo: Freepik

About the author: 

Maria Piknova, PhD, is a biochemist and science blogger specialising in microbiology and molecular biology. She is passionate about translating complex science into clear, evidence-based insights. [ORCID / LinkedIn]

Imagine your immune system as a highly skilled army that tirelessly protects your body from invaders. This army needs the right tools and signals to work at its best. This is exactly where immunomodulators come into play. These are substances that can fine-tune our body’s defences and keep them in perfect balance. 

What Are Immunomodulators and Why They Matter

Immunomodulators are biologically active substances that can adjust, boost, or calm down the immune system’s activity. The really clever thing about these compounds is that they can either enhance (immunostimulants) or reduce (immunosuppressants) the activity of the immune system depending on what your body needs.

When you have an infection or cancer, they can rev up your defences to fight harder. But when your immune system starts attacking your own body by mistake, as in autoimmune diseases, immunomodulators can tell it to calm down and stop the friendly fire. This is why they are often studied as part of modern immunomodulator therapy.

Classification of Immunomodulators

Scientists classify immunomodulators in several ways, depending on their origin, chemical structure, and effect on the immune system:

• by origin – they can be natural (derived from plants, fungi, microbes, or animals) or synthetic (lab-made).
• by chemical structure – some important types of immunomodulators include polysaccharides (complex sugars), polyphenols (plant antioxidants), terpenoids, alkaloids, proteins, saponins, and flavonoids.
• by their effect – some act as immune boosters (immunostimulants), while others serve as immune calmers (immunosuppressants).

You can find many examples of immunomodulators in everyday life, such as curcumin in turmeric, resveratrol in grapes or quercetin in onions. Natural substances, especially those from plants and mushrooms, have been used in traditional medicine for centuries. Today, modern research continues to explore their benefits, often confirming that they can support immune health with fewer side effects than synthetic drugs. 

Immunomodulators vs Immunosuppressants vs Immunostimulants

Not every substance that affects the immune system works in the same direction. Some push the accelerator, some pump the brakes, and some can do both depending on what your body needs.

Immunomodulators are the broadest category. The term covers any substance that can adjust or regulate immune function, including those that either stimulate or suppress it. The main types include:

• immunostimulants – boost immune activity and increase the production of signalling molecules that coordinate your body’s defences. They are useful in fighting infections, cancers, or immune deficiencies.
• immunosuppressants – deliberately calm immune reactions to prevent damage. They are essential after organ transplants and in autoimmune diseases where the immune system mistakenly attacks healthy tissues.
• some biologic drugs can act as both, depending on the situation. Their effect varies with timing and clinical context.

The main difference is that immunomodulators are the umbrella term for any agent that modifies immune function, while immunostimulants specifically increase immune activity and immunosuppressants specifically decrease it.

This distinction shows a key truth about immunity: stronger isn’t always better. The art lies in knowing which dial to turn and in which direction. A decision that depends entirely on whether your immune system needs encouragement, restraint, or just a gentle course correction.

Synthetic vs Natural Immunomodulators 

Here’s something most people don’t realize: your immune system doesn’t care whether the help it gets comes from a rainforest plant or a pharmaceutical factory. But the way it receives that help? That’s where things get interesting.

Synthetic immunomodulators like interferons and corticosteroids represent the pharmaceutical industry’s precision tools. These drugs are engineered for one thing: hitting immune targets hard and fast. They’re the special forces of immune modulation, designed to produce rapid, potent effects when your body needs immediate intervention. 

But here’s the catch: all that power comes with a price tag. These synthetic compounds can trigger significant side effects, from toxicity to unwanted immune suppression, which is why doctors monitor their use so carefully.

Natural immunomodulators tell a different story. Plant extracts like the bright yellow curcumin from turmeric, resveratrol from grapes, and certain fungal compounds and polysaccharides work more like gentle coaches than drill sergeants. In particular, arabinoxylans from rice bran (like the well-studied Biobran MGN-3) are noted for encouraging the immune system to work more efficiently while minimizing harsh side effects.

The important part? Neither approach is universally better. Choosing between synthetic and natural  immunomodulators isn’t about picking a winner in some ideological battle between science and nature. It’s about understanding that your immune system is complex enough to benefit from both approaches, used wisely and at the right times.

Arabinoxylans: Special Natural Immunomodulators

Arabinoxylans represent a particularly interesting group of natural immunomodulators. They are complex carbohydrates found primarily in the cell walls of cereals such as wheat, rice, barley, and oats.

Their structure consists of a backbone composed of xylose units, with side chains of arabinose sugars attached at various positions. They often also contain bound phenolic acids, such as ferulic acid, which can influence their biological activity.

The specific arrangement and branching of these sugars, along with the presence of phenolic acids, affect the way arabinoxylans interact with our immune system and with helpful gut bacteria.

One well-known example is Biobran (MGN-3), a rice bran arabinoxylan compound recognised for its gentle, natural immune-supporting properties.

Biobran MGN-3 Arabinoxylan Compound: Natural Immune Support from Rice Bran

Biobran, also known as MGN-3 arabinoxylan compound, is a fascinating plant-derived immunomodulator. Sourced from rice bran, this natural supplement isn’t your typical dietary fibre. It is specially enzymatically modified with an extract from the Shiitake mushroom (Lentinus edodes), which is the key to its immune-supporting properties.

What makes Biobran so intriguing is its ability to spark natural killer cells and cytotoxic T cells into action, boosting the immune system’s ability to recognise and destroy viruses and cancerous threats. 

Research shows it has potential to shield against viral invaders such as SARS-CoV-2, helping the immune system respond effectively without triggering dangerous side effects. Elderly and immunocompromised individuals, in particular, can benefit from its subtle boost, supporting a more resilient defense as years add up. It also helps fend off influenza-like illnesses while promoting overall immune balance. 

The real beauty of Biobran lies in its safety record: research shows it is well tolerated with no side effects even with long-term use. In an age where people crave gentle, effective support, Biobran may be proof that sometimes nature’s solutions are both elegant and practical.

The future of immunomodulators in medicine and prevention

The future of immunomodulators in medicine and prevention

Research on immunomodulators continues to evolve, bringing new insights into their mechanisms of action and potential applications. Polysaccharides such as arabinoxylans are emerging as promising candidates for the development of new therapeutic approaches.

Particularly interesting are combination therapies, where natural immunomodulators are integrated with conventional treatment procedures. Such approaches can enhance treatment effectiveness while simultaneously reducing side effects.

Future research focuses on gaining a better understanding of structure–function relationships of polysaccharides, optimising their production, and developing personalised therapies based on individual patient needs.

Natural immunomodulators such as arabinoxylans and Biobran MGN-3 thus represent a bridge between traditional and modern medicine, offering safe and effective options for supporting human health and immunity.

Frequently Asked Questions: Immunomodulators Explained

• What are immunomodulators used for? – Immunomodulators help control the immune system. They can boost it to fight infections and cancer or suppress it to stop the body from attacking itself, for example in autoimmune diseases or after organ transplants. In simple terms, they help balance the immune system by making it stronger when it’s weak and calmer when it’s overactive.
• What are immunomodulators examples? – Examples of immunomodulators include medicines such as interferons, imiquimod, and certain plant-based substances like Echinacea, curcumin, resveratrol, and arabinoxylans (e.g., Biobran MGN-3 arabinoxylan compound). These substances are used to modulate the immune response in various diseases, and their effects are supported by scientific research.
• Are immunomodulators safe? – Immunomodulators can be safe when used correctly and under medical supervision, but they may also cause side effects such as infections, allergic reactions, or problems with organs like the liver or heart. The risk depends on the specific drug, the person’s health, and how closely they are monitored, so regular medical check-ups are important while using these medicines.
• What is arabinoxylan compound? – Arabinoxylan compound is a type of dietary fibre made up of sugars found in the cell walls of cereal grains such as wheat, rye, and rice. It may support digestion and help maintain a healthy immune system.
• What is Biobran good for? – Biobran MGN-3 is a natural supplement made from rice bran that supports the immune system, helps protect the liver, and may reduce the risk of certain infections and illnesses, particularly in older adults. Research also suggests it may benefit brain health, support cancer prevention and wound healing, and improve overall quality of life.
• What is the chemical name for mgn3? – The chemical name for MGN-3 is arabinoxylan compound, which is a type of dietary fibre made from rice bran. It is sometimes also called arabinoxylan rice bran or modified rice bran arabinoxylan.
• Are immunomodulators biologics? – Immunomodulators are not always biologics, but some types are biologic drugs. Biologics are medicines made from living cells, and many modern immunomodulators, such as monoclonal antibodies and fusion proteins, belong to this group, while others are chemically synthesised and not biologics. 
• Are immunomodulators and immunosuppressants the same? – Immunomodulators and immunosuppressants are related but not identical. Immunomodulators are an umbrella term for substances that can either increase or decrease immune activity. Immunosuppressants fall under this group and mainly work to reduce the immune response, for example to prevent organ rejection or treat autoimmune diseases. 
• Are immunomodulators and immunostimulants the same? – Immunomodulators and immunostimulants are closely related but not the same. Immunomodulators are an umbrella term for substances that can either increase or decrease immune activity, while immunostimulants are those that specifically boost or strengthen the immune response.

References

• https://pmc.ncbi.nlm.nih.gov/articles/PMC9445227/ 
• https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1406213/full
• https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2024.1481850/full
• https://innovareacademics.in/journal/ijpps/Vol4Suppl1/3196.pdf 
• https://doi.org/10.1007/s44337-024-00029-3 
• https://doi.org/10.3390/nu16060881   
• https://doi.org/10.3390/nu13114133 
• https://doi.org/10.1016/j.jaci.2009.08.018
• Photo: Shutterstock

About the author: 

Maria Piknova, PhD, is a biochemist and science blogger specialising in microbiology and molecular biology. She is passionate about translating complex science into clear, evidence-based insights. [ORCID / LinkedIn]