Fibre and Gut Health: What You Need to Know
Why Fibre Matters for Gut Health
Fibre has moved back into the spotlight, and this time it’s not just about digestion.
During a recent Jim’s Gym nutrition talk, our resident dietitian Ian Thomas explained why fibre is becoming such a big focus in modern nutrition advice. Not as a trend for the sake of it, but because of its link to gut health, immune function, and long-term wellbeing.
If you’ve ever been told to “eat more fibre” without much explanation, this helps put things into context.
How much fibre do we actually need?
Current UK guidance recommends around 30g of fibre per day for adults. This is higher than older recommendations and reflects how much more we now understand about fibre’s role in the body.
Fibre feeds the gut microbiome – the community of bacteria living in the digestive system. Those bacteria influence digestion, inflammation, and how the immune system behaves.
Fibre, the gut, and the immune system
One of the key points Ian highlighted was the two-way relationship between the gut and the immune system.
The digestive system is our main point of contact with the outside world. When gut bacteria are well supported, they produce substances that help regulate immune responses.
There’s also a direct connection between the gut and the brain via the vagus nerve, which helps explain why digestion, mood, and mental well-being are often closely linked.
Not all fibre is the same
Fibre isn’t one single thing, and tolerance varies from person to person.
There are two main types:
Soluble fibre, which absorbs water and slows digestion
Insoluble fibre, which adds bulk and helps food move through the gut
Both play different roles, and not everyone responds to them in the same way. This is why gradual increases tend to be more effective than sudden changes.
Why variety matters
Rather than focusing purely on hitting a number, Ian encouraged thinking about variety.
Different plant foods feed different gut bacteria. A useful guideline discussed was to aim for around 30 different plant foods over the week. That includes vegetables, fruit, pulses, nuts, seeds, herbs, and spices.
As we age, digestion can become more sensitive, making a steady, varied approach far more effective than extreme changes.
What about protein and food trends?
Protein remains important, and recommendations may continue to rise over time. That doesn’t mean fibre should take a back seat – both work best together as part of a balanced approach.
We also touched on functional foods and heavily marketed products. Some are fine, but none are magic. Consistent habits and simple food choices still do most of the heavy lifting.
A sensible place to start
If fibre hasn’t been something you’ve thought much about before, there’s no need to overhaul everything overnight.
A good starting point is:
Adding one extra plant food to meals you already eat
Increasing fibre gradually
Paying attention to how your body responds
How this fits into Jim’s Gym
At Jim’s Gym, nutrition conversations like this sit alongside regular movement, routine, and community support. The aim isn’t perfection – it’s helping you feel better, move better, and understand what actually makes a difference.
FAQs
How much fibre should we aim for each day?
Current UK guidance recommends around 30g of fibre per day, but individual tolerance varies. Increasing intake gradually is important.
Is more fibre always better?
Not always. Some people experience digestive discomfort if fibre is increased too quickly or from certain sources.
What’s the difference between soluble and insoluble fibre?
Soluble fibre absorbs water and slows digestion, while insoluble fibre adds bulk and speeds transit. Both support gut health in different ways.
Does fibre affect the immune system?
Yes. Fibre feeds gut bacteria, which produce compounds that help regulate immune responses.
Want more support?
If you’d like regular movement, structure, and clear guidance alongside topics like this, Jim’s Gym brings everything together in one place.
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