What Is the Microbiome and Why Should You Care?

This ecosystem is called the microbiome, and scientists are increasingly convinced it may be one of the most important factors in human health, sometimes even described as a kind of “hidden organ.”

A World Within Us

The human microbiome refers to the collection of microorganisms like bacteria, viruses, fungi, and more, that live in and on our bodies. Most of them reside in the gut, but they also inhabit the skin, mouth, lungs, and even the reproductive system. 

Far from being harmful, many of these microbes are essential. Over millions of years, humans and microbes have co-evolved, forming a deeply interconnected relationship. 

In fact, your body contains at least as many microbial cells as human ones, and far more microbial genes.

Why It Matters: More Than Digestion

For decades, bacteria were mainly associated with disease. Today, that view has flipped.

Your microbiome plays a role in:

• Digestion and nutrient absorption
• Immune system regulation
• Metabolism
• Protection against harmful pathogens
• Even brain function and mood

Research has linked disruptions in the microbiome, known as dysbiosis, to a wide range of conditions, including obesity, diabetes, autoimmune diseases, and neurological disorders. 

In other words, your health isn’t just about your body, it’s about the ecosystem living inside it.

No Two Microbiomes Are the Same

One of the most fascinating discoveries is just how unique each person’s microbiome is.

Even among healthy individuals, microbial communities can differ dramatically, shaped by factors like diet, environment, genetics, and early life experiences, this means that what works for one person, whether it’s a diet, medication, or lifestyle, may not work the same way for another.

The First Years of Life: A Critical Window

One of the most exciting areas of microbiome research focuses on early life.

At Bar-Ilan University, Prof. Omry Koren, a Clarivate Highly Cited Researcher for eight consecutive years, has been at the forefront of understanding how the microbiome develops and why it matters so deeply.

His research highlights something remarkable:

The microbiome begins forming before and during birth and continues to develop through infancy, shaped by factors such as pregnancy, delivery, and breastfeeding. 

These early microbial exposures help “train” the immune system and influence long-term health outcomes.

In other words, the foundations of health may begin not just in our genes, but in our microbes.

The Microbiome and Pregnancy

Prof. Koren’s work has also explored how the microbiome changes during pregnancy.

These shifts appear to play a role in supporting a healthy pregnancy and fetal development. Researchers are now investigating whether targeted interventions, such as diet or probiotics, could help prevent complications. 

It’s a powerful idea: that by understanding microbial ecosystems, we may improve health even before a child is born.

A New Frontier in Medicine

Microbiome science is still young but it’s moving fast.

Scientists are already exploring:

• Personalized nutrition based on microbiome profiles
• Microbiome-based therapies for chronic diseases
• Fecal microbiota transplants (already used in some conditions)
• Links between gut bacteria and mental health

The challenge is that the microbiome is incredibly complex, it’s a dynamic, living network we are only beginning to understand.

So… Why Should You Care?

Because the microbiome changes how we think about health.

It shifts the focus from treating disease to understanding systems.
From “what’s wrong with the body” to “what’s happening inside the ecosystem.”

And perhaps most importantly, it reminds us that we are not alone.

We are, in a very real sense, superorganisms: human and microbial life, evolving together.