Germ Theory vs Terrain Theory: Building A Stronger Immune System | TOTAL HEALTH REVOLUTION® |

Ever wonder why you’re always catching a cold while none of your coworkers calls in sick to the office? Or maybe you’re the lucky one who always manages to run the gauntlet of flu season without so much as a sniffle? 

Turns out, your immune-status isn’t random or luck-of-the-draw. When you examine the differences between germ theory vs. terrain theory of disease you’ll better understand why you do or don’t get sick

While germ theory focuses on the virulence of the pathogen, terrain theory focuses on the condition and resilience-level of the host. 

In this article, I break down

  • The differences between germ theory and terrain theory.
  • Why your immune system may be weak.
  • Tips to increase your immune health.

What Is Germ Theory?

Every year, a new variant or variants of the influenza virus turn(s) up, and many people come down with the flu. 

We typically think of influenza as the cause of people getting sick with the flu. This perspective perfectly illustrates the germ theory of disease, in which a pathogen or “germ” (in the case of the flu, a virus) causes disease in exposed people. 

Louis Pasteur, a French chemist, popularized the idea that microorganisms cause disease, known as germ theory. 

Based on this theory, research in science and medicine has focused on ways to kill pathogens with medications, like

  • Antibiotics
  • Vaccines
  • Antivirals
  • Antifungals.  

Medications that kill pathogens can play an important role in managing certain diseases. But these medications don’t benefit those who want to prevent sickness in the first place.

Shortly after germ theory was proposed, Claude Bernard suggested the terrain theory of disease, and germ theory vs. terrain theory continues to be debated to this day.

Problems with Solutions Based on Germ Theory

In germ theory, solutions to disease are focused on and reactive to pathogens–either you seek to kill the pathogen outside of yourself before you’re infected (think: disinfection), or you take steps to kill the pathogen once you’ve been infected.

Here, I’ll highlight some issues with two solutions that are based on germ theory: antibiotics and vaccines.


Some antibiotics are only available by prescription. Some are available over-the-counter. Some are even “natural” remedies–yes, even natural remedies have antibiotic properties.

Antibiotics kill your harmful bacteria right alongside your good bacteria, which research has demonstrated can be far from strategic and often counterproductive. Why?

Because good bacteria make up your gut microbiome, and your gut microbiome makes up 80% of your immune system. These good bacteria support immune health in countless ways, including but not limited to:

  • Suppressing the growth of harmful bacteria and fungi (think: yeast).
  • Helping to digest food and absorb nutrients from food.
  • Balance your inflammatory response.
  • Produce B-vitamins.1

There are situations where antibiotics are, in fact, strategic and necessary. Context is everything. But the usual motivating mentality behind an antibiotic-approach is not a deep understanding of context, it’s a default setting of kill-kill-kill. Kill-mode may not actually be the most strategic or effective or sensical route when you understand the human body and the differences between germ theory vs. terrain theory.


In the case of vaccines, although they are technically a preventative approach since they are intended to prepare your body to fight off future viruses, they are still pathogen- or germ-focused.

Vaccines aren’t without weaknesses. For example:

  • Vaccines are reactive to pathogen, meaning vaccines are only developed after a specific virus causes an illness
  • Vaccines only protect against one pathogen/virus.
  • Vaccines don’t always prevent disease from developing.
  • Research has observed vaccines made of live viruses may activate the innate immune response to a greater degree than non-living vaccines do.2
  • Some vaccines may be contraindicated for immunocompromised people, those with autoimmunity or sometimes those who are at risk for autoimmunity, and those who are allergic to vaccine ingredients. Be sure to speak with your qualified healthcare provider to discuss what is best for your unique body.
  • Vaccines are delivered alongside other ingredients, including preservatives and adjuvants (often heavy metals) that different people may respond to differently.

In the case of both antibiotics and vaccines, you can see the pathogen-focus of germ theory at play. 

As you compare germ theory vs. terrain theory, it becomes increasingly apparent germ theory isn’t primarily interested in the condition and resilience-level of the “host.” 

Terrain theory, on the other hand, is.

Germ Theory vs. Terrain Theory of Disease

According to germ theory, pathogens cause disease. But that logic doesn’t answer why some people get sick while that lucky friend never catches a cold. 

Terrain theory says, health isn’t as simple as “x causes y.” What’s more important are the conditions that allow x to have any effect to begin with. These conditions are the “terrain” of terrain theory.

The terrain theory of disease, proposed by physiologist Claude Bernard, views the “terrain” of the human body as more important than the pathogen itself. 

According to terrain theory, you only fall ill (or extremely ill vs. mildly ill) after pathogen-exposure if your immune system is too weak to fight off the disease. Terrain theory explains why some people get sick or very sick while others stay healthy or only get mildly sick after being exposed to the same germ. 

Terrain theory considers the whole individual–your unique

  • Genetics
  • Health history
  • Diet
  • Lifestyle
  • Environment
  • Stressors.

Terrain theory looks at the entire picture of your health rather than an oversimplified picture in which you’re exactly the same as everyone else, and a germ is all-powerful and affects everyone exactly the same way.

Isolate the Fish Or Clean the Tank? Terrain Theory Explained

There’s an old analogy about a goldfish that highlights the differences between germ theory vs. terrain theory. 

Imagine you bring home a new goldfish. You fill its fish tank with fresh crystal-clear water.

After a few weeks of feeding your fish and watching it swim, you begin to notice the water looks a little dirty and you realize you haven’t been changing the water often enough. You worry the fish will get sick. In fact, it’s already looking a little…off.

According to terrain theory, the logical response here would be to clean the fish tank, get a tank-filter, and, moving forward, regularly care for the fish’s environment–its water-quality, food, sunlight, etc. Maybe get it a fish-friend.

The logical response would not be to fill a plastic bag with clean water, place the fish inside the plastic bag, then place the plastic bag inside the dirty fish tank (bubble boy —> bubble fish). According to terrain theory, this is how germ theory responds to pathogens.

Essentially, you can seal yourself away from and fear pathogens, and take strong substances that might have unwanted side-effects to kill them (germ theory), or you can care for your terrain to address root cause, heal/prevent disease, and increase resilience (terrain theory).

What Causes A Weak Immune System?

The first step to help boost your immune system is to understand what causes a weak immune system to begin with. Two of the biggest culprits that drastically weaken the immune system are chronic inflammation and oxidative stress. 

Inflammation and oxidative stress are not inherently bad. In fact, they’re both essential functions of your immune response that act to fend off illness or promote healing from injury. The problem lies in chronic inflammation and oxidative stress. 


Inflammation is a process your body uses to help itself heal. When you’re injured or exposed to pathogens and toxins, your body responds by sending in fluid and antibodies. 

Acute inflammation is a healthy, normal response, and an important part of your immune system and healing process.

But it can get out of control if you’re constantly living in an inflamed state.

Long-term inflammation, even at low levels, causes oxidative stress and lowers your cells’ ability to produce antioxidants.3

Causes of chronic inflammation include:

  • Chronic infection
  • Exposure to toxins, including chemicals, heavy metals, and pollution
  • Autoimmune disease, such as arthritis, multiple sclerosis, and Crohn’s disease
  • Oxidative stress
  • Emotional stressors, such as work or relationship problems.

Oxidative Stress

Chronic oxidative stress damages cells, proteins, and your DNA. Oxidative stress is caused by the production of free radicals (unstable molecules that react with other molecules in your body). 

You can experience oxidative stress as a result of

  • Inflammation (can result from multiple stressors, including but not limited to diet, environmental toxins, endogenous toxins (i.e. toxic hormones), etc.; inflammation is a normal and healthy response, but chronic inflammation can become problematic) 
  • Air pollution
  • Cigrette smoke
  • Radiation
  • Chemicals, such as chlorine, pesticides, and cleaners
  • Heavy metals
  • Mold
  • And more.

Damage from oxidative stress increases your risk for all types of disease, such as:

  • Infection
  • Metabolic diseases, including diabetes, metabolic syndrome, high blood pressure, etc.
  • Cancer
  • Autoimmune disease
  • Alzheimer’s.4 

When you take into account the effects of long-term stress and inflammation, the distinction between germ theory vs. terrain theory of disease becomes straightforward. Essentially all of the mentioned terrain-antagonists create oxidative stress.

You can counteract free radicals with antioxidants. Antioxidants protect your health by neutralizing free radicals before they damage tissue. To optimize your terrain, you should:

  1. Reduce oxidative stressors
  2. Enhance antioxidant-support.

We simply can’t ignore how our bodies and habits as a whole influence our immune health and susceptibility to illness

So let’s look at how to improve your “terrain” to help prevent illness before it even has the chance to start. 

Tips For Strengthening Your “Terrain”

There’s actually a lot you can do to build up your immune system. And most of it is much simpler than you’d imagine. Often people go straight for supplements while ignoring the basic habits that build a robust immune system. Try these healthy habits and test for yourself the effectiveness of germ theory vs. terrain theory of disease.

Get Enough Quality Sleep

Sleep does more than keep you in a good mood. Research demonstrates that sleep improves your body’s defense against pathogens and helps your body recover from oxidative stress

To get a better nights sleep, commit to:

  • Going to bed and wake up at the same time every day
  • Sleeping in a dark, cool room
  • Reducing your exposure to blue light and electronics before bed.

You may also want to consider non-habit-forming sleep aids. 

Melatonin to Support Sleep, Immunity, and Healthy Terrain

While relaxing herbs, like chamomile, passionflower, hops, etc., are sleep-aid options, they can be hit or miss from person to person. 

In general, I’m a fan of melatonin, because it’s safe, effective, and does more than just support sleep. Melatonin enhances immunity. 

And with all the light-pollution in the modern world, melatonin levels are often negatively impacted, so supplemental-melatonin support is further beneficial.  

But don’t take my word for it. Here’s what the research says about melatonin’s ability to support healthy terrain:

  • According to this study published in the journal Immunity and Ageing, “Melatonin enhances both innate and cellular immunity.”5 
  • Per a study published in the Journal of Pineal Research, “Melatonin has been effectively used to combat oxidative stress, inflammation and cellular apoptosis and to restore tissue function in a number of human trials.6
  • This study published in the Polish journal Acta Biochimica Polonica, explains “Melatonin’s functions as an antioxidant include: a), direct free radical scavenging, b), stimulation of antioxidative enzymes, c), increasing the efficiency of mitochondrial oxidative phosphorylation and reducing electron leakage (thereby lowering free radical generation), and 3), augmenting the efficiency of other antioxidants.” The study promotes melatonin’s use as an antioxidant and for during disease, saying, “clinical tests utilizing melatonin have proven highly successful; because of the positive outcomes of these studies, melatonin’s use in disease states and processes where free radical damage is involved should be increased.”7

Melatonin should be taken shortly before retiring. Suggested daily amounts vary, ranging from 0.5 mg to 10 mg. One research study suggests “between 1 mg and 6 mg” was most effective for improving sleep in older adults.8  

As you learn more about germ theory vs terrain theory of disease, I hope you see how melatonin’s function as an antioxidant can play a powerful and effective role in enhancing immune function.

Eat Whole Foods 

Processed foods full of sugar and starchy/processed carbohydrates both

  • Trigger chronic inflammation
  • Impair your healthy bacteria, allowing more toxins to reach your bloodstream.9 

Instead, aim for a diet full of healthy fats, including saturated fats, salt, and low-starch vegetables. (You can read more about healthy foods in my articles Is Saturated Fat Bad For You? No!, Is Too Much Protein Bad For You?, and Think You Know the Facts About Carbs? Don’t Be So Sure).

Consume Vitamins And Minerals 

Vitamins A, C, D3, K, zinc, selenium, and magnesium are particularly important for immune health.

If you’re eating a diet full of healthy foods, chances are you’re getting plenty of beneficial micronutrients. But sometimes nutrients aren’t abundant enough in soil so your food is deficient, or sometimes your body’s ability to properly absorb and use nutrients is impaired.

Consider functional testing and profiling to assess vitamins and mineral status. Work with a skilled practitioner who really knows how to run the right labs and interpret results (not just read results line-by-line right off the page). Abundant nutrients may be circulating in your blood, but that doesn’t mean those nutrients are getting into and being optimally used by your cells. It’s important you work with practitioners who don’t oversimplify lab-interpretation (many do).

Clean Drinking Water

If you live in a developed area, you may assume the water coming through your tap is safe to drink. While you likely won’t fall ill from germs in your tap water, that doesn’t necessarily mean your water is safe for your health long-term

The germs may be gone, but chemicals like chlorine and fluoride are still present in tap water. These chemicals trigger oxidative stress and inflammation and impact your health over time–yes, even at the approved “safe” levels.

A high-quality water filter is a game-changer for your immune health. You can read more about contaminants in water and my top picks for the best water filters in my article The Best Water Filters to Remove Contaminants in Water.

Air Quality

Air pollution impacts your immune system in unhealthy ways and increases inflammation.10 Low air-quality lowers immune system resilience, affects gastrointestinal health, and puts you at higher risk for lung diseases.

Outside your home, you have limited control over air quality. But you can still minimize the effects of air pollutants on your immune system. 

Research indicates that consuming vitamins—C, D, E and B—and long-chain polyunsaturated fatty acids found in fatty fish help counteract the harmful effects of air pollution.11 

Still, indoor air pollution is arguably more impactful for modern humans because we spend so much time indoors. Indoor toxins include the likes of mold, chemicals from paint, floors, furniture, etc. Inside your home, you can improve air quality with

  • Air filters: Studies show that air purifiers help to reduce the number of particles floating in the air, helping to improve air quality.12 
  • Indoor plants: Plants do more than liven up a living space. They also remove pollutants from the air, increase humidity, and reduce temperature. Indoor plants remove unhealthy particles like formaldehyde, benzene, and toluene. And the more types of plants, the better the air quality.13 Be sure to properly water your plants and let them drain so they don’t grow mold.
  • Dehumidifiers: If necessary, a dehumidifier can lower humidity to prevent toxic mold growth.

Stress Management

A hectic schedule is all too common in our modern world. Learning to control your stress levels does wonders to protect you from illness.

Research has long shown that stress increases cortisol levels and inflammation.14 

Occasional stress wouldn’t be a bad thing if we were just quickly running away from danger like cavemen thousands of years ago. But experiencing stress on a daily basis—from work, financial troubles, relationships, family life—all wears away at your immune system.

Stress-management techniques reduce the cortisol response to stress.15 Implement some of these (very affordable) ideas to help balance your stress levels:

  • Practice mindfulness meditation
  • Practice yoga or stretching
  • Go for a walk
  • Do a low-to-moderate-intensity workout 
  • Talk with a friend or family member
  • Drink calming herbal tea.

As you tend to foundational ways to improve your immune system, you’ll likely see results that will further clarify your understanding of germ theory vs. terrain theory. 

Here are a few more in-depth ways to monitor your immune health.

Insulin and Blood Sugar Testing

High blood sugar levels and low insulin sensitivity trigger chronic inflammation and oxidative stress and drastically affect immune health. Research indicates people with metabolic diseases like diabetes are more susceptible to infections and take longer to heal from illness and injury.16

Even prediabetes can weaken your immune system due to chronic slight elevations in blood sugar levels

Ask your qualified healthcare practitioner about testing your blood sugar and insulin levels to see if metabolic stress could be impacting your immune health. 

Learn more about hidden blood sugar sabotagers in my article Stop Wondering Why “I Eat Almost No Carbs And My Blood Sugar Is Still High.”

Optimize Detoxification and Antioxidant-Support with Glutathione

Glutathione (GSH) is a tri-peptide composed of glutamate, cysteine, and glycine. It is sometimes called the “master” antioxidant because glutathione protects tissues from damage caused by oxidative stress. 

Glutathione even helps to protect cells from viruses. Studies show healthy levels of glutathione can prevent influenza infections and other viral diseases.17,18 

Testing Your Glutathione Levels

Ask your doctor to check your glutathione levels to obtain a better picture of your total oxidative stress levels and your immune health status. While you can test glutathione directly, I usually test gamma-glutamyl transferase (GGT) levels. GGT is a biomarker of glutathione levels. 

Testing will help you to strategically select supplements, as opposed to driving with a blindfold. 

Glutathione Supplementation for Immune Health

Glutathione supplementation supports your antioxidant levels and overall “terrain.” Glutathione deliver can be done via

  • Oral supplementation
  • Topical patches or creams
  • Intravenously (IV)
  • Intramuscular shots.

Forms + Suggested Daily Amounts of Glutathione Available As Supplements

You can buy glutathione supplements in the following forms:

  • Reduced glutathione
  • S-acetyl glutathione 
  • Liposomal glutathione.

Personally, I’ve found success taking oral glutathione. Research demonstrates the beneficial effects of reduced glutathione up to 1g (1000mg) per day.19 I’ve used both liposomal glutathione as well as the converted-form, s-acetyl glutathione. (Learn more about my experience with glutathione in my article Finding The Best Glutathione Supplement.) 

One way or another, now that you have a better understanding of germ theory vs. terrain theory of disease, glutathione remains a powerful antioxidant supplement most people in the 21st century would benefit from.

Key Takeaways

  • The discussion of germ theory vs. terrain theory of disease has been an ongoing debate for centuries.
  • Germ theory tells the story of germs overriding the immune system to cause the same illness in every person who comes in contact with the pathogen.
  • Terrain theory teaches the health of the whole body impacts immune health and disease risk
  • Chronic inflammation and oxidative stress weaken your immune system and increase your risk for infectious and chronic diseases.
  • Simple habits like sleeping enough, eating nutritious foods, managing stress levels, drinking filtered water, and having plenty of antioxidants help build up your immune health.
  • Ask your doctor about checking insulin, blood sugar, glutathione (GSH), vitamin, and mineral levels to take a more in-depth look at your immune health.

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Feature image Copyright Erika Herman. “Bacteria” illustration copyright Maxim Kuikov, “Bacteria Icon Illustration” copyright creativepriyanka, and “Grey Bactetria Icon Isolated on White Background” copyright valeriimingirov.