In the latest issue of My Sunday News, T.R. Kerth’s column “All roads lead to bugtown,” cited recent research on the importance of our “friendly microscopic buddies.” Mr. Kerth accurately and rather imaginatively described bacteria that reside in our body’s cells as “taking over,” making you more “bugs than body.”
While that thought might make some readers squeamish, looking at these microscopic bacteria from a medical perspective might prove reassuring. As Cleveland Clinic has reported, “The gut microbiome is a hot topic these days in medical and wellness communities, and it’s easy to see why. These critters seem to have so many tentacles in so many different body systems that it’s possible to imagine they might hold the key to understanding and treating a wide range of intractable diseases.”
Already in 2026, several research studies focusing on the microbiome were published including a March article in Nature heralding the groundbreaking discovery that 50 new bacteria on which humans depend have been identified in the human gut alone.
So what is a microbe? Microorganism? And a microbiome? And what do they have to do with bacteria?
Let’s start with some definitions. Although the terms microbe and microorganism are used interchangeably and both are too small to be seen by the human eye (thus “micro”), microbe is a slightly broader term. It includes bacteria, viruses and fungi, while microorganisms refer to only those microbes that are considered living organisms which technically narrows the focus to bacteria. Bacteria are microorganisms with a much simpler cell structure than other organisms. Although simple in structure, their ability to affect the human body is amazingly complex.
Because Americans are familiar with the damaging effect bacteria can have on our health causing infections and illness, for many people bacteria carry negative connotations. Thanks to recent medical discoveries, the truth is that bacteria are indeed, as TR Kerth so clearly pointed out, not only beneficial but essential to our survival. It turns out the vast majority of bacteria are helpful, not harmful to humans. Mayo Clinic estimates that fewer than 1% of all known bacteria are harmful to human health. The great majority are either completely harmless or directly beneficial to human survival.
Bacteria coexist with other microbes in communities residing in the human body. Those communities are known as the microbiome. The critical role of the microbiome is not surprising considering that there are more microbes in the human body than cells. According to the National Institute of Health (HIH) approximately 30 trillion human cells to 38 trillion bacterial cells. Despite their great number, bacteria are also very small (Bacterial cells are generally 10 to 100 times smaller than human cells.
That results in a microbiome that is very small but very powerful. In other words, micro in size but macro in the way they contribute to human health and wellness. They protect us against pathogens, help our immune system develop, and enable us to digest food to produce energy.
Where is your microbiome?
Although the gut microbiome is the best known, each body site – for example, the gut, skin, and oral and nasal cavities, all have different communities of microbes and that microbiome is composed of a collection of different and unique microbes to help the human body survive.
Because the microbiome in the gut is the most active and has been studied more than others, next month’s Health Report will focus on the busy community of microbes in the human gastrointestinal tract. Research suggests that microbes in the GI tract may help support weight management, mood, immune function, and longevity. Stay tuned for studies that explore the remarkable abilities of the gut microbiome in ways scientists are only beginning to understand.
Reader follow-up — The BBC Science Focus has published a helpful guide: The human microbiome: Everything you need to know
