Your guide to fibre supplements 🧠
Should you take them, which ones, and how to start
New stats out last week - 96% of us aren’t getting the fibre we need.
So if we’re falling short, can a fibre supplement help fill the gap?
What we’ll cover today:
What fibre supplements actually do (and don’t)
5 key things to keep in mind when starting fibre supplements
What the recommended doses are for each fibre type
DIY your own whole food fibre supplement (paid subscribers)
Why fibre matters (brief refresher)
Fibre is a type of carbohydrate, found in fruit, vegetables, beans, whole grains, and nuts and seeds.
Fibre isn’t only important for keeping you regular, it’s doing a lot behind the scenes too.
It’s important for your gut microbiome - feeding your gut microbes, helping them make healthy molecules.
Fibre is also linked to better heart health, steadier blood sugar, and a lower risk of many diseases including type 2 diabetes and bowel cancer.
We often talk about fibre as if it’s just one thing. But it’s actually a group of different types of fibres that each can have a range of characteristics.
Not all fibres are the same.
Each type of fibre can have different actions for your health - but it’s also worth noting that it also means that the amount you can eat without getting symptoms (like bloating, nausea, gas, and cramping) can vary.
And how much you can tolerate also depends on you too - your genetics, gut microbiome, diet, if you have any health conditions (or gut issues).
What fibre supplements are (and aren’t)
Fibre supplements are powders or capsules made from isolated plant fibres.
Some types, like psyllium, help you stay regular by soaking up water and adding bulk to your poo. Others, like inulin or FOS, are fermentable fibres that feed your “good” gut microbes, helping to support a healthy microbiome.
What they don’t do, though, is come with all the extra benefits of fibre from whole foods, like vitamins, minerals, and plant compounds (did you know there’s more than 26,000 compounds in food?) that work together to support your overall health.
That’s why food should always come first when it comes to fibre.
But they can be helpful if you’re struggling to get enough fibre from food alone, but just be aware that they’re not a silver bullet.
5 things to keep in mind with fibre supplements
If you're thinking about adding a fibre supplement to your daily routine, here are a few things to keep in mind to help your gut adjust smoothly and get the most benefit:
Food first, supplements second – aim to get fibre from whole foods where you can
Choose the right fibre for your goal – different types do different things
Start small and increase slowly – give your gut time to adapt
Listen to your gut – if you get gas, bloating or cramps, slow down or adjust
Drink plenty of water – especially important with bulking fibres like psyllium
Using a mix of fibre types may offer more balanced support for gut health, since different fibres do different things, like helping keep you regular or feeding your gut microbiome.
A breakdown of common types
Fibre supplements work in different ways. Fermentable fibres feed your gut microbiome, viscous fibres help with cholesterol levels and blood sugar control, while insoluble fibres tend to help keep you regular.
Psyllium husk: A gentle fibre that soaks up water and forms a gel in your gut. It helps make stools softer and easier to pass, and is often used for constipation and IBS.
Inulin: A type of prebiotic fibre found in chicory root. It feeds your “good” gut microbes, but it can cause bloating in some people, and can trigger gut symptoms for those with IBS.
FOS (Fructooligosaccharides): Like inulin, FOS can cause bloating, gas, and discomfort, especially in people with IBS or sensitive guts. FOS is often more rapidly fermented than inulin, which can lead to more noticeable symptoms.
Polydextrose: A man-made fibre that helps add bulk to your stools and keep things moving. It’s only partly fermented, so tends to cause less bloating than others.
GOS (Galactooligosaccharides): Feeds your “good” gut microbes. It’s usually easy on your digestion too, less likely to cause bloating than some other fibres like inulin or FOS, especially if you stick to small amounts.
Resistant starch: Found in foods like green bananas and cooked-and-cooled potatoes. It resists digestion and feeds your gut microbes.
Acacia fibre (Gum Arabic): A very gentle fibre that feeds your gut microbes without causing much bloating. It mixes easily into drinks and easy on even sensitive guts.
PHGG (Partially Hydrolyzed Guar Gum): A kind-to-sensitive-guts fibre that helps keep you regular, and supports your gut microbes, without causing much gas or bloating.
If you have a sensitive gut, it’s better to start with gentle fibres like psyllium, PHGG, β-GOS, and acacia, while inulin and FOS are best added in slowly or avoided.
Possible doses
These are upper level amounts for each type of fibre - you don’t need to take this much - shown in studies to be gentle enough for most adults without causing strong symptoms beyond an increase in gas (do expect to be more windy, at least for the first 3 weeks).
Psyllium husk: 15g/day
Inulin: 5g/day
FOS: 7.8g/day
Polydextrose: 12g/day
GOS: 20g/day
Resistant starch: 12g/day
Acacia fibre: 20g/day
PHGG: 6g/day
If you have a health condition – especially something like IBS or IBD – or take any medication, it’s best to check with your doctor first. Some fibre types might not suit you, or you may need to start with a smaller amount to avoid digestive troubles.
Start low and go slow
To help your gut get used to fibre and avoid side effects, it’s a good idea to increase it slowly, especially with types like inulin, GOS or FOS that can cause more gas.
Start with about a quarter to a third of the full amount
Slowly increase. Aim to reach the full amount over 2–4 weeks
It’s best to take fibre with meals, and spreading it out across the day can be easier on your gut.
Make sure you’re drinking plenty of water, especially if you’re using bulking fibres like psyllium.
If you start to feel bloated, gassy or crampy, just slow down or cut back a little until your body adjusts. Any symptoms like bloating or gas usually show up in the first 12 to 24 hours, and often start to settle within a day or two.
DIY your own whole food fibre supplement
With this simple blend, you’ll get the benefits of fibre, along with a dense mix of other nutrients too.
Just 2 tablespoons adds 6.6g of fibre!
Great stirred through Greek or kefir yoghurt for breakfast, with mixed berries and a handful of nuts.
Ingredients:
Keep reading with a 7-day free trial
Subscribe to Second Brain to keep reading this post and get 7 days of free access to the full post archives.