Antibiotics and Probiotics…The Same Thing?

Ever wonder the difference between probiotics and antibiotics and prebiotics? Here I’ll explain how antibiotics are a natural product of bacteria, it’s only man’s use of antibiotics that makes them dangerous.

As humans, we like to put things in the perspective of good and bad, good vs. evil, darkness and light.  We have come to consider probiotics “life giving” and antibiotics “life taking” but this is not entirely the case. Many of the microbes we consider to be “probiotic” manufacture antibiotics and dispense them on a regular basis, so how can a good microbe create such a bad substance?

Wouldn’t life have burned itself out ages ago?

For the average person, antibiotics don’t spell the end of the world.  They don’t automatically sentence you to a life of autoimmune diseases and gut problems.  The way modern medicine and the livestock industries use antibiotics, however, is extremely inappropriate and is causing problems on a global scale.  The best course of action for the average person is to use antibiotics only when absolutely necessary, ie. to prevent or remove a possibly life-threatening infection.

It’s well known that medically administered antibiotics save lives by killing germs, we also know that antibiotics don’t just have the ability to kill disease causing microbes, but all microbes—good and bad.  It’s also well known that microbes quickly become resistant to antibiotics making it harder and harder to effectively kill them and treat infections.  Antibiotics save lives, but the cost is high: The microbiome of a person receiving antibiotics is changed— normally for the worse, microbes soon become resistant to antibiotics, and antibiotic resistant microbes can be spread between humans like a slow-moving plague.  Expectant mothers given antibiotics have a less diverse microbiome to seed the new baby, babies given antibiotics are starting life with a crippled second-brain, and anyone else given antibiotics will experience a change in their gut microbiome that can lead to a dysfunctional gut microbiota.

The Differences between Probiotics and Antibiotics

The term “probiotic” is an interesting conflagration, it combines the Latin preposition pro (meaning “for”) with the Ancient Greek adjective βιωτικός, or biotic (“life”).  It’s fitting that this word comes from these two languages as many great ancient philosophers such as Aristotle, Hippocrates, and  Lucretius used Latin and Greek in their earliest pondering on the subject of “invisible life.”

The term “antibiotic” is pure Greek, meaning against, opposed to, or preventing life. Antibiotics are amazing molecules manufactured by the microbes that live primarily in the dirt, but are equally at home inside most animals. Produced mainly by members of the Actinobacteria phylum of microbes (which includes many probiotic species), antibiotics play a fascinating role in maintaining equilibrium anywhere microbes live[1].  Microbes are great judges of character—they know who the enemy is and they’ve evolved ways to deal with him. One way is through antibiotics.
A discussion about antibiotics and probiotics is almost the same as discussing apple trees and apples.  You can’t have one without the other. For billions of years probiotic strains of microbes pumped out rivers of antibiotics and life was grand…cruel, but grand.  Then along came man with his sense of misguided justice and monstrous brain.
One of the early proponents of beneficial bacteria, Eli Metchnikoff, received a Nobel Prize for Medicine in 1908; he stated:

The dependence of the intestinal microbes on the food makes it possible to adopt measures to modify the flora in our bodies and to replace the harmful microbes by useful microbes.

Selman Waksman, antibiotic pioneer, was bestowed the 1952 Nobel Prize for Medicine for “his ingenious, systematic, and successful studies of the soil microbes that have led to the discovery of streptomycin.”  In his acceptance speech, Waksman stated:

With the removal of the danger lurking in infectious diseases and epidemics, society can face a better future, can prepare for a time when other diseases not now subject to therapy will be brought under control. Let us hope that in contributing the antibiotics, the microbes will have done their part to make the world a better place to live in.

The term “probiotic” was first coined in 1965 to describe, not beneficial microbes, but ‘substances secreted by one organism which stimulate the growth of another.’  For the first time it was acknowledged that not all “germs” are bad.  As this line of research blossomed, the term probiotic became synonymous with the microbes being studied and not the substances they secrete.  Most, if not all, of the microbes we consider probiotic are equally at home in the dirt as they are in our intestines. Probiotics existed before humans comprehended or acknowledged them, and blindly exploited this synergistic gift for hundreds of centuries.  A head of cabbage or a bowl of milk will quickly be preserved by one of a number of probiotics, microbes which naturally spew out antibiotics that secured their own growth whilst deterring the growth of other microbes.  Many of the probiotics also secrete lactic acid, which is an antibiotic in the classic sense, and also makes the food tastier and easier to digest[2]. The modern definition of probiotics extends generously to the beneficial microbes found in fermented foods and beverages as discussed earlier, our gastro-intestinal tract, the soil microbiome, isolated from animal microbiomes, and commercial bacterial and fungal probiotics.

The term “antibiotic” was first used in 1941 to describe any small microbe-produced molecule that slowed the growth of other microbes.  This natural occurrence had been known for centuries, but it wasn’t manipulated until the 1920’s when Selman Waksman, Ukrainian-American inventor, biochemist and microbiologist who studied organisms that live in soil, unearthed and cataloged numerous antibiotic-producing strains[3]. About the same time, Alexander Fleming was also making discoveries that invisible life had a few tricks we could use to our advantage.[4]

Probiotics have been studied extensively as a way to re-establish microbial equilibrium and prevent disease. Under ideal situations, a probiotic is a microbe that under scrutiny must not be of a nature that will likely cause harm to the recipient and it must be of a variety that normally inhabits the human gastrointestinal tract.  In the days of old, these probiotics would have come from nature, as nature intended, but in our modern times we have become disconnected to a large degree with the sources of these beneficial microbes.  Rarely do we eat half-rotted fruit, dirty roots, or drink water from puddles in which ducks and hippos waddle in.

What does this all mean?

Without animal hosts to protect them, microbes got inventive.  Not only are they protecting themselves, though, they are also protecting the growing plant or rotten apple they cling to.  They protect it from other microbes or even insects who may consume it before their life-cycle is complete.  However, when a microbe produces antibiotics, it doesn’t use them to kill other microbes, rather it sends them a signal—a signal telling them that that this particular piece of real estate has been claimed[5].  Like a light tap on the hand of a child sneaking a cookie causes said small hand to recoil in mortal fear of mother’s scorn, some of the ‘chemical signals’ trigger part of the cell membrane of the encroaching opportunist to dissolve or burst. Flag planting and tail rattling has been just enough, for billions of years, to keep peace in the microbial garden of life.

Living among us have always been microbes with the propensity to cause harm should they be accidentally ingested or introduced as through a wound.  This affects not only humans, but all living things, even the microbes themselves.  We’ve all evolved mechanisms to avoid these harmful situations and must be cognizant we don’t intentionally eat contaminated food, drink contaminated water, or touch contaminated objects. Our microbial inhabitants have perfected their ability to protect us from normal amounts of harmful pathogens, such as their ability to produce antibiotics, but even they can become overwhelmed.  Religious edicts, superstitions, and folklore have arisen over the centuries to warn us against pathogenic microbial overload, but man’s attempts to protect us from the “invisible life” has made us more vulnerable.

Take Home Message:

People with a healthy gut biome need not fear taking occasional rounds of antibiotics to fight off an infection or as a precaution before surgery. However, most people do not have a healthy gut biome!  Probiotics, whether purchased or consumed in foods, help keep our gut flora diverse and healthy. Eating high fiber foods, and periodic potato hacks are very good habits for anyone who has taken, or is about to take, antibiotics.

[1] Velho-Pereira, S. “Antimicrobial Screening of Actinobacteria using a Modified …” 2011. <>
[2] Ljungh, A. “Lactic acid bacteria as probiotics.” 2006. <>
[3] “Selman Waksman and Antibiotics – Landmark.” 2013. 1 May. 2014 <>
[4] Clardy, J. “The natural history of antibiotics.” 2009. <>
[5] Romero, D. “Antibiotics as Signal Molecules.” 2011. <>

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