#WednesdayWisdom Series // Dietary Fibre + Prebiotics


🤓 I’ve discussed the gut microbiome and probiotics before, but have left out a very important part of the gut health puzzle until now – dietary fibre and prebiotics.

🧐 What is DIETARY FIBRE? It has a few slightly different definitions, but the term generally includes all carbohydrates that are neither digested or absorbed in the small intestine of human beings (who lack enzymes required to break them down) and have a degree of polymerization of ≥3 (plus lignin, which isn’t technically a carbohydrate).

🥖 Carbohydrates including oligosaccharides, resistant starch, and non-starch polysaccharides (pectin, cellulose) all fall under this definition.

🍐 SOURCES of dietary fibre include fruit, vegetables, nuts, and seeds, and despite what Paleo/Whole30 supporters suggest, all whole grains and legumes are AMAZING, affordable sources of dietary fibre that are really important for gut health.

🥗 What are PREBIOTICS? These are non-digestible food components that stimulate the growth and/or activity of gut bacteria. They kind of act like a fertiliser for the good guys that are sooo good for our gut, helping them grow and thrive more than the bad guys.

💊 Although there are plenty of prebiotic supplements out there that promise to help you meet the optimal prebiotic intake (or even max it out), there is really no evidence to show that consuming prebiotics through supplements has any direct health effects. Consuming them through whole foods is likely the best way to get prebiotics into your gut.

👅 They are found naturally in foods such as Jerusalem artichokes, chicory, onions, garlic, asparagus, and leeks. It’s important to note that PREBIOTICS are a type of dietary fibre, but that not all dietary fibre is prebiotic. Our bodies aren't able to break down prebiotic fibres, which means they are able to reach our large intestines intact to be broken down and fermented by our gut microbes.

🍌 What is RESISTANT STARCH? This is a form of starch that cannot be digested in the small intestine and passes to the colon where it is fermented by beneficial gut bacteria to produce short-chain fatty acids, which are known to benefit gut health. RS is found in unripe bananas, cooked & cooled starches (potato/pasta/bean salads), oats and cashews.

🥐 WHY is dietary fibre important? Dietary fibre helps our digestive systems work well and promotes regular bowel movements. Dietary fibre is also known to promote gut health, prevent constipation, improve satiety, and even possibly reduce our risk of developing colon cancer and cardiovascular disease.

🥪 HOW can you eat enough fibre each day? UK guidelines currently recommend 30g dietary fibre/day. This seems like quite a bit but is far from impossible to consume each day with the right food choices. Well as a starting point, @nicsnutrition shared this great post with a few easy examples of a day’s worth of food that’ll help you meet the 30g/day target.

Here are a few more simple tips and things to take into consideration to up your dietary fibre intake:

  1. If there is no medical reason for you to avoid gluten, then don’t cut gluten-containing whole grains out of your diet! Gluten-free alternatives to popular foods contain far less fibre, and often more sugar than their wholegrain gluten-containing counterparts.

  2. Choose whole grains over refined alternatives. This includes wholegrain cereals like oats, quinoa, and barley, wholewheat pasta, wholemeal sourdough, and wholegrain crackers.

  3. Enjoy a diverse, adventurous, plant-filled diet. One of my favourite gut-health experts, @theguthealthdoctor, often suggests that we should try to get as many different types of plant-based foods into our diet each week. VARIETY is key to supplying different types of dietary fibre, as well as other nutrients, to your gut.