How to eat for a healthy gut microbiome (and why it matters for your hormones, mood, and more)

What you eat doesn’t just nourish you - it also feeds the trillions of microbes living in your gut. And when your gut microbiome is thriving, so is your digestion, your hormones, your immunity, and even your mood. Have you ever noticed your digestion feels better when you eat more plants, or that you feel more sluggish after a week of takeaways? That’s your gut microbiome talking.

This article breaks down how to eat in a way that supports your gut microbiome - without extremes or complicated rules.

Why your gut microbiome matters

Your gut microbiome is a vibrant community of bacteria, fungi, and other microbes. When your microbiome is in balance, it supports digestion, hormonal balance, reduced inflammation, and even your brain chemistry (including the production of neurotransmitters). Around 90% of serotonin, the neurotransmitter that supports your mood, is produced in the gut - not in the brain.

That means what’s happening in your gut can ripple out to how you feel physically, emotionally, and mentally. A nourished microbiome supports hormonal rhythms, insulin sensitivity, and immune resilience.

❓ An imbalanced microbiome can show up as irregular bowel movements, diarrhoea or constipation, bloating, fatigue, brain fog, skin issues, or mood swings. The good news: nutrition and lifestyle can positively shift your microbiome within just a few weeks.

What your gut microbes love

Your food choices determine which microbes thrive. Beneficial bacteria feed on fibre, polyphenols (plant compounds that give fruits and vegetables their colour), and fermented foods. Less beneficial bacteria, on the other hand, grow in diets high in sugar, low in fibre, or heavy in ultra-processed foods.

Eat more fibre

Prebiotic fibre found in fruits, vegetables, legumes, whole grains, nuts, and seeds is the fuel your gut bacteria love most. When they ferment it, they produce short-chain fatty acids, which strengthen the gut lining, lower inflammation, and help prevent “leaky gut.”

🐍 Your gut lining is made up of several layers. The layer of gut cells is only one cell thick, yet it plays an important role in your immune defence. A strong gut lining keeps toxins, unwanted microbes, and undigested food particles out of your bloodstream. Eating fibre is like reinforcing the front door of your body.

Try to eat as many different plant-based foods as possible. Research shows that aiming for 30 different plants per week is a great goal. It may sound like a lot, but the count adds up quickly when you include fruits, herbs, nuts, seeds, and a variety of vegetables in your meals.

Add fermented foods

Fermented foods like yogurt, kefir, kimchi, sauerkraut, miso, and kombucha add live probiotics to your gut. They don’t settle there permanently but help support a balanced ecosystem and can aid digestion and mood.

✋🏼 Pro tip: If you’re new to fermented foods, start small - especially if you have IBS or sensitive digestion. Look for “live cultures” or “unpasteurised” on labels to make sure the probiotics are active.

What to limit (without guilt)

Ultra-processed foods

Additives, preservatives, and low-quality fats can disrupt your gut microbes. They’re also usually low in fibre, leaving your microbiome underfed.

⚖️ Realistic: No one’s saying you can never have a piece of cake again. What matters is not turning ultra-processed food into a habit. That’s why the 80/20 rule is recommended: 80% whole, unprocessed foods; the other 20% leaves room for foods that may be less healthy for your gut, but possibly good for your mind. ;)

Sugar and constant snacking

Too much sugar feeds less friendly bacteria and yeasts/fungi in the gut. How often you eat also matters: if you snack all day, your gut doesn’t get the chance to activate its natural cleansing wave (the migrating motor complex). Over time, this can lead to bloating and bacterial overgrowth.

That’s why it helps to space your meals at least 3–4 hours apart and aim for an overnight fast of about 12 hours (for example, from 8 p.m. to 8 a.m.).

Final thoughts

Your gut microbiome is dynamic and responsive. Even small, consistent changes to how you eat can make a big difference over time. Focus on variety, fibre, and fermented foods, and treat your gut like the ecosystem it is - one that thrives with care, patience, and plenty of colourful plants.

Sample week of gut-friendly eating

Breakfasts: Overnight oats with kefir and berries; scrambled eggs with greens and mushrooms; chia yogurt bowls.
Lunches: Lentil soup with sourdough; quinoa tabbouleh; chickpea salads with herbs and seeds.
Dinners: Salmon with quinoa and sauerkraut; tofu stir-fry with kimchi; baked sweet potato with tahini and tempeh.

Simple recipes to try

Gut-friendly rainbow salad: grated carrots, red cabbage, cooked lentils, mixed seeds (pumpkin, sunflower, flax), lemon-olive oil dressing, optional: a spoonful of sauerkraut on top

Turmeric miso broth: 1 tsp miso paste, 1/2 tsp turmeric, grated ginger, boiling water, add chopped spinach and tofu cubes

Berry chia yoghurt bowl: 1/2 cup plain yogurt (or kefir), 1 tbsp chia seeds, handful of berries, sprinkle of oats and crushed walnuts

References:

Frame, L. A., Costa, E., & Jackson, S. A. (2020). Current explorations of nutrition and the gut microbiome: a comprehensive evaluation of the review literature. Nutrition Reviews, 78(10), 798–812. https://doi.org/10.1093/nutrit/nuz106

Gibiino, G., De Siena, M., Sbrancia, M., Binda, C., Sambri, V., Gasbarrini, A., & Fabbri, C. (2021). Dietary Habits and Gut Microbiota in Healthy Adults: Focusing on the Right Diet. A Systematic Review. International Journal of Molecular Sciences, 22(13), 6728. https://doi.org/10.3390/ijms22136728

Lares-Michel, M., Zyanya Reyes-Castillo, & Fátima Ezzahra Housni. (2023). Towards the characterization of sustainable diet’s gut microbiota composition and functions. Gut Microbiome, 4. https://doi.org/10.1017/gmb.2023.13

What you eat doesn’t just nourish you - it also feeds the trillions of microbes living in your gut. And when your gut microbiome is thriving, so is your digestion, your hormones, your immunity, and even your mood. Have you ever noticed your digestion feels better when you eat more plants, or that you feel more sluggish after a week of takeaways? That’s your gut microbiome talking.