Discover the trillions of microorganisms that call your body home and their profound impact on your physical and mental health
We are not alone in our bodies. Each person is home to 1 trillions of bacteria, viruses, and other microorganisms that have evolved alongside humans over millions of years, creating a complex ecosystem that profoundly influences our health for better or worse.
Composition of Human Microbiome
This collection of microorganisms, known as the 1 human microbiome, represents a hidden organ that scientists are just beginning to understand—one that could light paths to better health and revolutionize how we treat disease.
The gastrointestinal tract alone hosts over 2 1,000 bacterial species, approximately 10 times more cells than our own "human" cells. These microbial communities are not passive passengers but 4 active participants in our physiology, shaping immunity, metabolism, neurodevelopment, and even how we respond to medications.
In a radical new concept, humans can be considered a "holobiont"—a single biological entity comprising human and resident microbial cells working in concert 2 . This perspective opens exciting possibilities for developing entirely new types of medicines and health strategies based on these microbes.
While often used interchangeably, these terms have distinct meanings. 3 Microbiota refers specifically to the microorganisms themselves—the bacteria, archaea, viruses, fungi, and protozoans that inhabit a specific site on or in the body.
The 3 microbiome is a broader concept that includes not only the microorganisms but also their genomes and the surrounding environmental conditions.
Analogy: If microbiota are the trees, the microbiome is the entire forest ecosystem.
One of the most fascinating discoveries in microbiome science is the 1 gut-brain axis—a bidirectional communication network linking your gastrointestinal system with your central nervous system.
This connection explains why nurturing the gut microbiota could help resolve conditions like depression and anxiety 1 , and why the relationship between the gut microbiome and the brain might lead to new treatments for Parkinson's disease 1 .
Compelling evidence now links the composition of gut microbial communities to mental health conditions 1 . Researchers are exploring how specific microbial profiles might contribute to or protect against depression and anxiety.
The relationship between the brain and gut microbiome is revealing surprising insights into Parkinson's disease 1 . Researchers have discovered that the gut microbiome of Parkinson's patients differs significantly from that of healthy individuals.
Some researchers are investigating whether Parkinson's might actually originate in the gut before manifesting in the brain.
The gut microbiome appears to be 1 crucial to the success or failure of immunotherapy—a revolutionary cancer treatment that harnesses the immune system to fight tumors.
This has led to experimental approaches using 1 2 faecal microbiota transplants to convert non-responders into responders.
Inflammatory Bowel Disease (IBD), including Ulcerative Colitis and Crohn's Disease, represents a chronic recurring inflammatory disorder of the gastrointestinal tract that affects more than 1.6 million people in the USA and 2.5-3 million in Europe 2 .
Existing therapies have been far from satisfactory for disease control, let alone remission, creating a significant unmet medical need 2 .
Americans with IBD
Higher healthcare costs
Europeans with IBD
Microbiotica, a company spun out from the Wellcome Sanger Institute in 2016, set out to develop targeted microbiome-based therapeutics for IBD and other conditions 2 .
The company developed a sophisticated platform that combines the world's most diverse microbiome culture collection with a proprietary Reference Genome Database, advanced informatics, and machine learning capabilities 2 .
Using their unique platform, they identified specific bacterial strains that were consistently present in patients who responded well to therapy but absent or diminished in those who didn't improve 2 .
They designed a unique live bacterial therapeutic consisting of a precise combination of beneficial bacteria that could potentially restore healthy microbial community function 2 .
The therapeutic candidate was tested in humanized microbiome models to verify its effects and understand its mechanism of action before advancing to clinical trials 2 .
| Bacterial Species/Group | Association with Health/Disease | Potential Therapeutic Role |
|---|---|---|
| Bacteroides strains | Varied by specific strain | Certain strains associated with healthy state |
| Prevotella species | Context-dependent | Modulation of immune response |
| Clostridium species | Some beneficial, some pathogenic | Production of anti-inflammatory compounds |
| Bifidobacterium species | Generally beneficial | Gut barrier reinforcement |
| Lactobacillus species | Generally beneficial | Immune regulation |
Microbiotica's work has shown striking effects in novel disease models, demonstrating that precisely formulated bacterial combinations can have therapeutic potential 2 . Their candidate, MB310, has displayed significant promise in preclinical studies, moving the company toward initial clinical trials with human patients 2 .
Microbiome researchers employ a diverse set of tools to understand the composition and function of microbial communities 6 .
Measures diversity within a single sample, capturing how many different species are present and how evenly distributed they are 3 .
Measures differences between samples or groups, helping researchers understand whether microbiome compositions differ significantly between, for example, healthy individuals and those with a specific disease 3 .
The recognition that we are holobionts—amalgams of human and microbial cells—represents a fundamental shift in how we understand human biology 2 . This perspective opens exciting new possibilities for preventing and treating disease by nurturing our microbial partners.
Precisely formulated bacterial combinations tailored to individual needs.
Personalized nutritional recommendations based on microbial profiles.
Microbiome-based tests for disease risk and treatment response assessment.
Targeted microbial transfers for specific health conditions.
While research continues, each of us can contribute to our own microbial health through simple practices: eating a diverse, fiber-rich diet; minimizing unnecessary antibiotics; and engaging with nature—all ways to nurture the trillions of microscopic partners that call our bodies home.
As this field continues to evolve, we're moving toward a future where microbiome medicine becomes an integral part of healthcare, transforming how we maintain health, treat disease, and understand what it means to be human.