15 Things You Should Avoid to Keep Your Microbiome From Turning Against You

The trillions of microorganisms that colonize your body shape your thoughts, behavior, and general health. Hence, it goes without saying that you would be wise to take your microbiome into account when you plan your life: what you eat, when you go to bed, how much you exercise, and so forth.

It’s not just important to bring things that are known to positively affect the microbiome into one’s life; it’s also important to avoid things that are known to negatively affect the microbiome. In today’s article, we’ll talk about 15 such things. Some of these things you probably already know about, however, others may be new to you…

1. Antibiotics

Over the past ten years, more and more people have picked up on the fact that all of the antibiotic substances that we humans have infused into our environment – our homes, the guts of sick people, pets, and domesticated animals, the fields we use to grow our food, and so on – over the most recent decades have changed the workings of our world, in particular the workings of the microbial communities that surround us, including those that colonize our bodies.

The days when it was believed that antibiotics are harmless drugs that doctors should have few quarrels about prescribing to their patients are long gone. All medical professionals who’ve bothered to keep up with the research now knows that antibiotics don’t just wipe out “bad” bugs, but also many good ones, and that long-term antibiotic use sets the stage for dysbiosis, immune dysfunction, and chronic inflammation/disease (1, 2, 3, 4).

If you are severely sick and have to take antibiotics to get better and/or survive, you should obviously get some antibiotics into your body. That said, if you can get away with not using them, you would be wise to avoid them. By enhancing the powers of your microbiota and immune system via the adherence to a healthy diet and lifestyle you can build up the natural defenses of your body and thereby largely eliminate your need to use antibiotic substances to keep pathogens at bay.

2. Social isolation

Social isolation is one of the most powerful nemeses of the healthy microbiota. Not only are people who spend most of their time alone less likely to pick up friendly microbes from other people than folks who are socially active, but research suggests that they are more prone to stress, depression, and many other mental health-related problems (5, 6, 7) (all of which may adversely affect microbiota health), in large parts because they don’t have anyone to talk to and spend a lot of time “in their own head”.

We humans evolved to be social. We require social contact to thrive and be healthy. It’s obviously good to have some time for oneself every now and then; however, it’s not good to be very socially isolated.

Signals travel in both directions between the gut and the brain. A healthy gut and a healthy brain go hand in hand. The one can’t exist without the other. A brain that is not regularly stimulated by real-life conversations/verbal communication is not a healthy brain.

3. Artificial foodstuffs

The ancestral nutritional environments that imposed the selective pressures that contributed to shaping the human genome were devoid of artificial foodstuffs, including emulsifiers, artificial sweeteners, and antimicrobial preservatives. Hence, it’s not surprising that modern research has revealed that many artificial ingredients found in various modern foods adversely affect our health and well-being (8, 9, 10). The microbiota mediates some of this effect (8, 9, 11).

The type of microbiota that is produced by a diet heavy in artificial foodstuffs differ from the one that is produced by a whole foods diet. Seeing as it’s the latter type of microbiota that the human body evolved alongside, it’s not surprising that that is the type of microbiota that agrees best with the human biology.

4. Other pharmaceutical drugs

Antibiotics are not the only pharmaceutical drugs that are capable of messing with the microbial communities we harbor. Far from it. Many other drugs, including non-steroidal anti-inflammatory steroids and statins, have been shown to possess microbiota-disrupting properties (12, 13, 14). Again, if you are sick and have to use a drug to keep your body from breaking down, you should obviously think twice before you steer clear of that drug. The point here is not that you should avoid all drugs at all cost; but rather that if you can, you should go the drug-free route.

5. Chronic psychological stress

Intense stress, in particular stress of the chronic type, doesn’t do a microbiome good (15, 16, 17). It opens the gut up to dysbiosis and dysfunction. This is something you probably know if you have a stressful job or have experienced a stressful event, trauma, or period in your life.

Our bodies are well-equipped to handle short bursts of acute stress, seeing as that’s the main form of stress our ancient ancestors faced. They are not good at dealing with prolonged/chronic stress though, which is unfortunate, seeing as artificial light, hectic work schedules, modern technology, and other things that are capable of raising our stress levels are a natural part of our modern lives.

6. Body care products and cosmetics that contain ingredients of questionable safety

Your skin is teeming with microbes, which together form complex communities. These microbial communities are no different from those that are found in your gut in that they too are prone to “act up” if they are exposed to something that bring them out of their comfort zone. Not only do some body care products and cosmetics contain ingredients that problematic skin bugs, such as the acne-promoting bacterium Propionibacterium acnes are fond of, but regular, frequent use of certain types of cosmetics and soaps, in particular those that contain antimicrobial substances, may dry out the skin and make it a less hospitable environment for friendly bugs that are an essential part of the skin’s defense against pathogens (18, 19). If you are to use cosmetics, you would be wise to pick products that are as natural as possible and that contain as few skin-irritating ingredients as possible.

7. Excessive hygiene

This point follows from the last one. Our obsession with hygiene may be harming our health. Perhaps needless to say, in certain situations, cleanliness is important. You would be wise to wash your hands if you’ve come into contact with raw meat or other potential sources of pathogens. Also, if you visit a hospital (hospitals are notorious for harboring many pathogens) and end up touching many surfaces or patients there, you should consider cleaning your hands or maybe even your whole body afterwards.

That said, there’s no doubt that many modern humans are too clean for their own good. If you wash your hands many times every day with soap and/or frequently apply antimicrobial lotions or gels to your skin, you may think you’re enhancing your protection against germs, but in reality, you’re most likely tearing down your defenses, as opposed to building them up, seeing as your behaviors perturb the natural pH levels of the skin and alter the microbial communities that live there (18, 19, 20).

8. Sick people and animals

Whereas physical contact with healthy people and pets can help enhance the diversity and resilience of your microbiota, contact with unhealthy organisms may do the opposite. This idea is supported by recent research, which shows that the microbiotas of people who live together often evolve in similar directions and that pet owners pick up bacteria from the animal or animals they host (21, 22). This transmission of microbes is obviously not inconsequential; it does affect the health of the organisms that are involved.

The fact that sick people are a source of pathogens helps explain why we have evolved ways to detect disease in others even before it breaks out (23) and why we tend to avoid sick people and animals. Perhaps needless to say, you shouldn’t neglect the care of sick people and pets just because they are a source of pathogens. You would be wise to try to limit your exposure to the microbial communities that sick organisms harbor though.

9. Highly processed foods

Nutrient-dense, whole foods are your best allies in the fight for a better and more diverse microbiota. Highly processed foods, on the other hand, are arguably your greatest enemies. They are capable of disrupting the microbial ecosystems you harbor, bringing disorder and imbalance into your gut (24, 25, 26, 27). It doesn’t take many weeks or months for this to happen. Even a single unhealthy, high-fat meal will nudge your microbiota in an unfavorable direction (28).

10. High-potency probiotics

Yes, you read that correctly. Unlike what some people seem to think, it’s not wise to bombard one’s gut with probiotics. It could be argued that the name probiotic, which means pro life, is a misnomer. Probiotics are not harmless bugs that stand in the corner while their peers fight alongside themselves in order get a hold of the resources they need to survive and reproduce. They, like all other organisms, are programmed to fight for their survival. Hence, it shouldn’t come as a surprise that many probiotics produce bacteriocins that kill or inhibit the growth of other bacteria (29). Even if the effects of these bacteriocins are only directed towards “unfriendly bugs”, that wouldn’t necessarily mean that it’s safe to take in a lot of the probiotic in question, seeing as the consumption of large quantities of probiotics is an evolutionarily novel behavior that may perturb the microbial communities of the gut.

11. Physical inactivity

Up until very recently, all humans on this planet were physically active on a regular basis. Physical activity contributed to shaping the human body and mind. It undoubtedly also contributed to shaping the human microbiota, seeing as physical activity affects virtually all aspects of the body, including the workings of the gut. The body of a person who is physically inactive works differently than the body of a person who is physically active; hence, it’s not surprising that recent research suggests that exercise affects the gut microbiota (30, 31, 32) or that the microbial communities harbored by athletes differ from those that non-athletes host (33). As long as it’s not excessive, exercise appears, not surprisingly, to have a beneficial effect on the microbiota (30, 32).

12. The use of light-emitting devices before bed

All of the artificial light that’s come flooding over our world during the most recent centuries is not only messing with our brains and our production of the sleep-hormone melatonin; it’s likely also messing with the microbial communities we harbor. Recent research has shown that the quality and duration of our sleep contribute to shaping the composition of our microbiotas (33, 34). Not surprisingly, sleep deprivation has been shown to unfavorably affect gut microbiota composition (33, 34). Seeing as light-emitting devices such as cellphones and computers are very high on the list of things that can make us sleep deprived, it goes without saying that we would be wise to limit our use of those devices, particularly late at night.

13. Smoking

Cigarette smoking not only causes local inflammation of the airways and lungs, which may in turn cause lung cancer and other disorders of the respiratory system; it sets the stage for systemic inflammation and ill-health. Not surprisingly, smoking alters the microbiota: not only the microbial communities of the respiratory system, but also those that reside in the mouth and gut (35, 36, 37, 38, 39, 40). Some of the adverse health effects of smoking are undoubtedly partly caused by these changes in the microbiota (35, 36, 37, 38, 39).

14. Pollution

Recent research suggests that exposure to various pollutants, including Polychlorinated Biphenyls (PCBs), could alter the composition of one’s microbiota in an unfavorable way (40, 41, 42). This isn’t surprising, seeing as we humans evolved to live in nature, not in big, congested, industrialized cities. Natural selection has never gotten around to reconfiguring the human body so that it works well in a highly polluted environment, which hosts different microbial communities than a non-polluted one.

Many different types of pollutants can harm our health and disturb the microbial communities we harbor. It’s obviously impossible for the modern, city-dwelling man to completely avoid pollution. However, it is possible to take some precautions (e.g., stay out of highly polluted areas, avoid using house paint that give off toxic fumes) in order to limit one’s exposure to pollutants.

15. Mold

Mainstream medicine pays little attention to mold and the threat it poses to human health. Don’t let this fool you into thinking that mold isn’t a real danger. Both household mold and mold-contaminated food can seriously damage your body, including your microbiome. Chronic mold exposure has been linked to a myriad of health issues, including fatigue, depression, and brain damage (43, 44, 45, 46, 47, 48). This isn’t surprising, seeing as we humans are not well-adapted to live in a mold-heavy environment. We evolved to live in nature; not in damp, moldy buildings. Moreover, our primal ancestors ate primarily fresh food; they didn’t store foods for prolonged periods of time and thereby run the risk of mold growth.

Your best defense against toxic mold is a healthy microbiota coupled with a strong immune system. That said, even if you do possess those things, you’re not immune to the harmful effects of toxic mold exposure. It’s a little known fact among the general public that antibiotics such as penicillin were not originally produced by humans. Rather, they are derivatives of fungi-produced compounds. Hence, it goes without saying that if you’re frequently exposed to toxic mold and the mycotoxins they produce, regardless of what the source is, it’s not only your own body that will suffer, many of the “friendly bacteria” you harbor probably will as well; both because they will be directly affected by the molds and the mycotoxins they produce, and because they will be affected by changes in the immune and health status of their host.

The bottom line is that if any of the buildings you frequent are water-damaged, moist, and/or old, you should investigate whether they have become infected with toxic mold, particularly if you notice a moldy smell. Moreover, you would be wise to avoid foods (e.g., nuts, grains) that have been stored for long periods and thereby may harbor more molds than what your body can safely handle.