Have you ever heard people talk about their gut microbiome or ‘gut bugs’ and wondered what it all means? Read below to learn more about this fascinating world inside you.

Meet your gut’s microscopic residents

Bacteria graphic

If most people hear about ‘gut bacteria’, their first thought is of bacteria that can make you unwell, like Salmonella. However, your gut is also home to trillions of ‘beneficial’ bacteria, tiny, but powerful residents inside the whole of your gut, that help keep us alive and thriving. They’re like a bustling city inside you, full of specialists doing different jobs. In return for food and shelter, these microbes help you digest meals, boost your immune system, and provide a range of other important functions to help our health.

Think of your gut bacteria as your personal support team:

  • Food Processors: They break down fibre and starches, turning them into energy-boosting chemicals.
  • Vitamin Factories: They whip up essential nutrients like B vitamins (for energy) and vitamin K (for blood clotting).
  • Security Guards: They fight off harmful invaders and train your immune system to stay strong.
  • Mood Managers: Research suggests they may even influence emotions like anxiety and happiness—who knew your gut had a say in your mood?
  • Pharmacy Technicians: They help determine how well a range of medications work in your body.

How do scientists study these tiny helpers?

Photo of test tubes
to grow all of the bacteria, and some bacteria wouldn’t survive outside their natural environment. But in the mid-2000s, scientists figured out how to create a list of all the bacteria in a specific environment by looking at and reading their DNA. This process is called DNA sequencing and it changed the game! It allowed researchers to identify microbes in your gut by using poo samples (yes, science can be gross, but fascinating). Following on from this, scientists found out that your intestines house 100 trillion bacteria from over 1,000 different species—outnumbering your human cells by 1.3 to 1. You’re basically more bacteria than human!

Your unique microbial fingerprint

No two microbiomes are alike. Your gut’s microbial mix is shaped by your genes, diet, medication, and environment, making it as unique as your fingerprint. Instead of focusing on specific bacteria, scientists now look at what jobs these microbes perform—like digesting fibre or regulating immune responses. Just like a well-functioning city, it’s the teamwork that matters!

Why a diverse microbiome matters

A healthy gut is a diverse gut. When the balance is thrown off, trouble can sometimes follow:

  • Infections: Normally, gut microbes keep harmful bacteria like C. difficile [CD6] (aka “c diff”) in check. However, when antibiotics wipe out good bacteria, these troublemakers take over, causing nasty diarrhoea.
  • Inflammation: Conditions like Crohn’s disease and ulcerative colitis are linked to microbiome imbalances.
  • Weight and metabolism issues: Changes in gut bacteria are tied to obesity, diabetes, and liver disease.
  • When the different types of bacteria is limited (low diversity), this can influence how you respond to cancer drugs.

Here are some promising approaches:

  • Probiotics: These are live ‘beneficial’ bacteria that are usually taken in a capsule or as a drink. The bacteria found in these supplements can temporarily influence gut function. While they won’t permanently move in, they may help balance digestion and immunity.
  • Prebiotics: Think of these as food for your good bacteria. Found in foods like garlic, onions, and bananas, prebiotics help beneficial microbes flourish.
  • Intestinal Microbiota Transplants (IMT) (also known as ‘faecal microbiota transplant’): Yes, it’s exactly what it sounds like—transferring gut bacteria from a healthy person (who has been screened to make sure they don’t carry any infections) into the gut of someone with severe imbalances. This is highly effective for conditions like C. difficile infections.
  • Postbiotics: These are beneficial byproducts that gut bacteria produce when they break down food. Scientists are studying their potential to improve gut health without needing live bacteria.
  • Precision medicine: Future treatments may involve custom-designed microbiome therapies tailored to an individual’s gut ecosystem.

The future of gut science

Researchers are on a mission to further understand the gut microbiome, the role in plays in certain diseases and health conditions and how to can be used to improve the lives of patients and the general public. With gut health linked to so many conditions—from digestion to mental well-being—we may all soon become gut gardeners, carefully tending to our own microbial ecosystems!

Links/resources

Introduction to Gut Bacteria (Guts UK! website)
The role of gut bacteria in health and disease (Guts UK!)