Gut Health: What Your Microbiome Is and Why It Matters

The human gut contains roughly 38 trillion microbial cells — bacteria, fungi, viruses and other organisms — collectively called the gut microbiome. This community has co-evolved with humans for hundreds of thousands of years and plays roles in our health that scientists are still discovering.

What the Gut Microbiome Does

• Digests complex carbohydrates (fibre) that your own enzymes can't break down
• Produces short-chain fatty acids that feed colon cells and regulate inflammation
• Synthesises certain vitamins, including K2 and some B vitamins
• Regulates immune system development and response (70% of immune cells are in the gut)
• Communicates with the brain via the gut-brain axis, influencing mood and cognition

Signs of a Struggling Microbiome

While the science is still developing, common associations with poor microbiome diversity include: irregular digestion, frequent bloating or gas, frequent illness, low energy, poor skin, and worsening anxiety or depression. These are associations, not diagnoses — but they're flags worth noting.

What Harms Your Gut

• Low-fibre diet — gut bacteria need plant fibres to survive and thrive
• Unnecessary antibiotic use — broad-spectrum antibiotics significantly reduce microbial diversity
• Chronic stress — the gut-brain axis runs in both directions
• Poor sleep — circadian disruption affects microbiome composition
• Ultra-processed food — emulsifiers and additives in UPF may disrupt gut lining integrity

What Actually Helps

• Eat 30+ different plant foods per week — variety is the single strongest predictor of microbiome diversity
• Include fermented foods: yogurt, kefir, sauerkraut, kimchi, miso, kombucha
• Eat adequate fibre: both soluble (oats, beans) and insoluble (vegetables, wholegrains)
• Manage stress through movement, sleep and connection
• Be cautious with antibiotics — always complete the course when prescribed, but avoid unnecessary use