You can use all the luminosity-giving skincare in the world, but if you’re lacking in fibre you’re unlikely to get the glow of your dreams

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Being told you 'need more fibre ’ feels like advice your granny might give, but if your skin is lacking a little in the glow department, fibre could be the beauty booster you're in need of. Clear-skinned supermodel Molly Sims, 47, is a convert to the high fibre diet, writing on her blog  that nutritionist Rebecca Baer advised she switched to a high fibre diet ahead of her wedding. Davina McCall , she of boundless energy and flawless face, is an avid follower of The Gut Health Doctor, Dr Meghan Rossi, who advocates eating 30 types of fibre per week. Davina says she can't live without Dr Rossi's Bio&Me Gut Loving Granola £4.99,  which has 15 types of fibre in one serving.

We all know fibre is key to gut health, keeping us regular, as well as beneficial in preventing diseases such as type one and type two diabetes. But a lesser-known superpower of fibre is the glow that it gives to skin. If we fill up on fibre it can help lead to glowing skin, clear of inflammation  that causes acne, eczema  and rosacea .

Unfortunately, we don't eat anywhere near enough fibre in the UK, consuming on average 14g per day according to French pharmacist Marie Drago, founder of microbiome skincare brand Gallinée. The World Health Organisation and the NHS recommend 30g per day, but we need 50g of fibre to eliminate inflammation, which can affect the skin resulting in inflammatory conditions such as acne and rosacea, says Marie.

How does fibre give your glowing skin?

1. Fibre keeps everything moving

If you’re not getting enough fibre in your diet you can experience irregular bowel movements or constipation.  These spell trouble for your complexion resulting in dull, tired skin and flare-ups.

“Regular bowel movements facilitate the elimination of toxins from your body, which helps to decrease inflammation," explains Valentina Cartago, nutritional advisor at Bio-Kult . which is often associated with common skin complaints such as acne, rosacea and eczema as well as puffiness, dark circles or rashes. An imbalance of gut microbes is commonly seen in a number of these skin conditions, so supporting a healthy microbiome through eating fibre rich foods may be of benefit for reducing symptoms.”

2. Fibre feeds your good gut microbes

Research emerging during the last three years has shown how much our gut affects our skin, as Marie Drago explained in our digital masterclass, The Gut-Skin Connection . In the same way that our gut is in constant conversation with our brain, our gut has an intimate dialogue with our skin via a connection known as the gut–skin axis.

“The gut and skin communicate and can influence each other," says Marie. "An unbalanced gut leads to skin inflammation in the form of acne, rosacea and eczema. Prebiotics found in fibre act on the gut level and send signals to the skin to reduce inflammation."

Different gut bugs feed on different sources of fibre, so it is vital to bring many different fibre-rich foods into our diets as we can. "Aim for at least 30 different forms of fibre in your diet in a week," says nutritionist Jennifer Medhurst.

Once we've fed the microbes, they certainly get busy. The billions of microbes living in our gut produce B vitamins which are essential for normal skin growth and repair, explains Dr Sabine Donnai of health assessment service Viavi.“The gut microbes thrive on fibre, so providing plenty of good-quality fibre will help enhance skin health by keeping those microbes happy and productive. A diet high in fibre means a healthy digestive system and this in turn will boost the health of your skin.”

MORE GLOSS: Is your skin condition caused by your gut?

3.  Fibre helps you absorb skin-supporting nutrients

“Fibre increases the absorption of essential nutrients and antioxidants,” nutritionist Lisa Richards  told US wellness website Well and Good. “Certain nutrients such as lutein, lycopene, and vitamin C are needed for collagen production and eating enough fibre enables your digestive system to absorb these nutrients more easily."

Eating fibre sources including guava, papaya, avocado and apple provide good amounts of skin-loving antioxidants to decrease inflammation. They also include bountiful vitamin C to support collagen production so it’s a win-win.

Walnuts are a good fibre-rich nibble too; they contain plant-based anti-inflammatory omega 3 alpha-linoleic acid. “Less inflammation in the skin means less risk of flare-ups,” explains Valentina.

4. Fibre reduces inflammation

You'll have gathered by now that a lack of fibre can lead to inflammation in the body in general but for the skin, it shows itself as acne, rosacea and eczema. "If you have leaky gut [when bacteria is absorbed into the bloodstream via a porous ('leaky') bowel] or inflammation in your gut, bacteria leaks into the blood and inflames the skin, degrading collagen, and provoking eczema and acne," explains Marie Drago. "You can reverse this with good bacteria, also known as probiotics  which will help add anti-inflammatory factors into the blood that will go all the way to the skin and soothe the skin."

MORE GLOSS: Are probiotics key to good health?

5. Fibre slows down ageing

Fibre could also be a key player in preserving the youth of our body, of which the largest organ is the skin. Fibre is though to help preserve our telomeres, which are the caps at the ends of each of our DNA that protect our chromosomes from becoming damaged. “Some of the health benefits associated with dietary fibre could be a result of the preservation of telomeres,” explains Jennifer Medhurst. “Studies have shown that adults with high fibre consumption have longer telomeres than their counterparts, suggesting significantly less biological ageing. Populations who live in the ‘blue zones’ where they see a record number of centenarians and people living well into old age healthily have a fibre intake significantly higher than in Western diets," continues Jennifer.

Which type of fibre is good for skin?

There are two main types of fibre: soluble fibre and insoluble fibre. Insoluble fibre does not dissolve in water and is the roughage that moves everything along. Soluble fibre, on the other hand, dissolves in water and many types of it feed the good bacteria in your gut, and are known as prebiotic fibre.

Plant foods tend to have a mix of both types of fibre with some having more than the other, for example, avocados have 13.94 grams of insoluble fibre and 3.06 grames of soluble and lentils which have 14.40grams of insoluble and 1.2 grams of soluble.

Insoluble fibre - what you need to keep everything moving

Insoluble fibre is key to healthy skin and digestive system. “Insoluble fibre (found in nuts and seeds, beans, cauliflower, potatoes, green beans and lentils –  what we call whole foods) helps your intestines absorb water from your body, softening your stools and increasing their bulk to support healthier and more regular bowel movements,” says Valentina. Regular bowel movements excrete toxins and unwanted waste from your body to help support glowing skin.

Insoluble fibre doesn't provide the 'prebiotic' food that gut bugs thrive on. However, one exception is a type of insoluble fibre called resistant starch, found in cooked and cooled potatoes, pasta rice, oats, green bananas and  tiger nuts . Resistant starch not only feeds gut bugs but also helps you stay fuller for longer thereby reducing skin-unfriendly snacking.

Prebiotic fibre - food for your good gut bugs

Prebiotic fibre is a type of soluble plant fibre found in fresh fruit and veg that dissolves in water and feeds your good gut bugs helping them to thrive, which in turn supports the gut skin connection. The bacteria ferment and thrive on it. Think of it as good bacteria fertiliser. The abundant good bacteria can then crowd out the bad bacteria, so reserve a space on your plate for this type of fibre.

"Prebiotic fibres are indigestible plant fibres that travel to your gut and feed your beneficial bacteria, supporting the composition and activity of our gastrointestinal microflora," says Valentina.

Look for prebiotic fibres found in fruit, vegetables and legumes, in particular, garlic, onions, leeks, slightly green bananas, Jerusalem artichokes and asparagus, advises Valentina. Inulin, found in many plants, is another form of prebiotic fibre beneficial to the gut.

If eating the advised 30 types of fibre per week seems unmanageable, supplementing is a good option. Indi Body supplement , £45 for 30 servings, is a berry and hibiscus flavour smoothie powder that has inulin to support the immune system and balance hormones, along with biotin and vitamin B12 .

Healthspan's EasyFibre Inulin , £12.95 for 450g is a powder form of fibre supplement made from 100 per cent chicory root to help support your digestive system which can be added to juice, water or to your meals.

If capsules are our preference try,  The Nue Co's Debloat supplement , £40 for 60 capsules, which has inulin or  Together Health's Multibiotic Microbiome Support , £14.99 for 30 capsules.

The moral of the fibre and skin story? Fill up on both soluble and insoluble fibre to nourish your gut microbes and to keep your digestive system moving, freeing the body from toxins that can dull the skin and contribute to inflammation and skin flare-ups.

"Let’s put all of the above information into practice," says Valentina. "Avocado toast sprinkled with sunflower and pumpkin seeds for breakfast, an apple with a handful of walnuts for a snack and a lentil stew for lunch and your vegetable soup for dinner. This is your one day plant-based, skin-loving, fibre rich menu,” Valentina suggests.

MORE GLOSS: What should you look for in a skin supplement?