Prebiotics and your gut 🧠what you need to know
Week 3 of '8 Weeks to a Thriving Gut' series
Welcome back to Week 3 of 8 Weeks to a Thriving Gut.
Last week, we explored fibre - the superstar food for your gut microbes.
This week, we’re narrowing the focus to a special type of fibre - prebiotic fibre.
Why?
Prebiotics are the ultimate fuel for your gut bacteria, helping them thrive and unlocking powerful health benefits for your digestion, brain, and beyond.
Here’s what we’ll cover today:
What is prebiotic fibre? How it goes beyond being just 'another type of fibre.'
Why prebiotic fibre matters: By fueling your ‘good’ gut microbes, prebiotics support your health, from your brain to your immune system.
Your action for the week: Add in more prebiotic-rich foods, with meal ideas and recipe suggestions.
What is a prebiotic?
ISAPP prebiotic definition
'a substrate that is selectively utilised by host microorganisms conferring a health benefit'
In simpler terms, a prebiotic has three key features:
It’s a specific substance.
It works by feeding specific gut microbes.
It has a positive effect on your health.
Most prebiotics are types of fibre, but not all.
Compounds like polyphenols (found in foods like berries and dark chocolate), and certain fatty acids can also act as prebiotics.
Other fibre types can still feed your gut microbes supporting overall gut health, but they don’t meet the strict definition of a prebiotic because they don’t target specific microbes or demonstrate direct health effects.
There’s no official daily recommendation for prebiotic intake yet. However, studies suggest at least 3-5 grams of prebiotics daily (from foods or supplements) is needed for gut benefits.
How are prebiotics different from probiotics?
Prebiotics are the food that feeds your gut microbes, while probiotics are the live 'good' gut bacteria.
Think of it like gardening:
Prebiotics are the soil and fertiliser that help certain gut microbes thrive, making molecules for your health.
Probiotics are the seeds we want to grow and flourish - specific ‘good’ gut bacteria that give you a health benefit.
Prebiotic supplements vs. whole foods
Most research on prebiotic fibres has been conducted using supplements, not whole food sources.
This is because supplements provide consistent, measurable doses, making them easier to study.
However, this doesn’t mean supplements are better - it simply highlights the need for more research on whole foods.
Prebiotic whole foods: Are rich in a diverse range of nutrients and fibre types.
Supplements: Convenient and concentrated, supplements can fill gaps or target specific effects but lack the variety and extra benefits of whole foods.
Whole foods are ideal for long-term gut health, while supplements can provide targeted support when needed.
What do prebiotic fibres do for you?
Research is still evolving, but these are some of the key benefits so far:
Gut health: They help block harmful bacteria and support your immune system.
Heart health: Prebiotics can lower ‘bad’ blood lipid levels and improve insulin sensitivity.
Bone health: They help with the absorption of minerals like calcium, supporting strong bones.
Mental health: They make metabolites that may boost brain function, energy, and focus.
Top prebiotic foods
Prebiotics are potent, so starting small is key! Remember last week’s low and slow method.
Prebiotic fibres are found in a range of plant foods. Here are some of the top ones:
Onions
Garlic
Leeks
Bananas (underripe)
Chicory root
Jerusalem artichokes
Asparagus
Beans
To get 3–5g of prebiotic fibre daily, remember that whole foods like onions (around 3.7g per 100g) contain smaller amounts compared to supplements.
As you boost your overall fibre intake to the recommended daily 30g of fibre, you’ll naturally increase your prebiotic fibre intake too, as they all add up.
Packaged foods like yogurts, cereals, breads, biscuits, desserts, and drinks may have added prebiotics.
Look for terms such as GOS, FOS, oligofructose, chicory fibre, or inulin on the ingredients list to identify them.
Your action for the week
Choose one prebiotic-rich food to add daily to your meals. Here’s some ideas you could try:
Breakfast
French onion omelette with salad greens
Boiled eggs with asparagus soldiers, and pumpernickel rye bread
Whole grain muesli with banana, berries, mixed seeds and Greek yoghurt
Snacks
Peanut butter and banana smoothie with flaxseeds, chia seeds, and oats
Hummus on rye crispbread crackers
Handful of mixed nuts
Lunch/Dinner
Saute garlic, onions, and leeks as a base for soups and stews.
Include Jerusalem artichokes in a tray of roasted veggies.
Mix cooked lentils into green salads or grain bowls.
Recipes
These recipes caught my eye this week - let me know if you try them!
- quick leeky beans on toast.
- broccoli, chickpea, and anchovy pasta.
- Jerusalem artichoke and leek soup with hazelnut and spinach pesto.
Next week…
Week 4 of the 8 Weeks to a Thriving Gut series covers the 101 on probiotic supplements - what to look for and if you really need them.
Feel free to leave a comment below - I love hearing from you.
Emily xx
Enjoyed this post? 🧡 and restack - it’d mean a lot!
Ahhh I'm here because I have a hard time digesting foods like onions & garlic so it seems mean / difficult that these are at the same time necessary to make my digestion better. 😥 Do you have any recommendations on how to deal with it? Would you recommend including those foods in low doses into my diet or would you rather exclude them if having a hard time digesting them?
Likewise, for someone who needs to avoid FODMAPs: Can you please suggest some FODMAP-friendly prebiotics? And probiotics?? Do supplemental digestive prescription enzymes destroy the prebiotic or probiotic beneficial effects?