Is a “standard” paleo diet high enough in fibre to optimally feed the gut microbiota? This is the question I have been asking after reading a lot about gut health recently. Jeff Leach of www.humanfoodproject.com recently wrote an interesting article Paleo versus Vegetarian – who eats more fiber? In this article he discusses some of the preliminary findings from American Gut Project, which suggest that many paleo people are only eating around 25g of fibre per day, compared to vegetarians at 32g and vegans at 43g per day. (Note that Jeff Leach describes this data as “not-so-great but interesting cross-sectional observational data” so we can’t rely on it too heavily.)
It got me thinking though, that even though most people I know eating a paleo diet do eat plenty of vegetables, there is a big focus on leafy greens and salads, which are not the highest in fibre.
- 100g of kale has 3.6g of fibre
- 100g of rocket (arugula) has 1.6g of fibre
- 100g of cooked carrots have 3g of fibre
At these sorts of values you would need to eat around 1kg of vegetables a day to get around 30g of fibre.
Compare this to some non-paleo foods
- 100g of cooked pinto beans have 9g of fibre
- 100g of oats have 10.6g of fibre
The other point to note is that most vegetables contain fibre in the form of non-starch polysaccharides. While these are an important source of fibre, there is also increasing evidence that we need to be eating more of a specific class of fibre called Resistant Starch. This is a polysaccharide that is resistant to digestion in the stomach and small intestine, and is then fermented by bacteria in the large intestine. Resistant starch is found in specific foods such as cooked and then cooled potatoes, rice and pulses/legumes. It is also found in green bananas, green plantains and tigernuts.
Another important fibre is inulin. This is found in foods such as raw onion, raw leeks and raw garlic, and also in chicory root, dandelion greens and Jerusalem artichokes. These are foods that again many people might not be including on a standard paleo diet as they are not that common, or not always eaten raw.
I recently submitted a gut bacteria sample to Ubiome and I am waiting on the results. This sample was submitted when I was eating a standard paleo diet but one which did not include many of the above foods, so I do not think it was particularly high in fibre.
Since submitting that sample I have started adding a lot more fibre to my diet and I plan to submit another sample after 6 weeks of this high-fibre paleo diet to see what, if any difference this has made.
My high-fibre (prebiotic) paleo diet
Each day for 6 weeks I plan on eating as many of the following as I can (plus my usual paleo foods of eggs, fish, meat, plenty of non-starchy vegetables, fruit):
- A salad of 50g raw leeks plus 1-2 cloves of raw garlic (inulin)
- 1 portion of cooked and then cooled potatoes, sometimes reheated, sometimes eaten cold (resistant starch RS3)
- A small handful of raw tigernuts and a handful of dried yacon flakes (resistant starch RS2 and FOS)
- A daily sachet of Bimuno (B-GOS)
- A high-fibre probiotic smoothie – recipe can be found here (green banana and tiger nut flour for resistant starch RS2, baobab for pectin, yacon syrup for FOS, oat bran for beta-glucan, frozen berries for polyphenols, gelatin, seeds (hemp/flax/chia))
- At least one cup a day of matcha green tea (polyphenols)
- 85%-100% dark chocolate for snacking on (polyphenols). I like Hotel Chocolat’s 100% dark chocolate drops for snacking on
- 1 tbsp psyllium husks in a little orange juice (I can’t stomach it in plain water, it makes me gag!)
When you increase your fibre intake you MUST do it gradually (I took two weeks to gradually up fibre dose before I got to the above and which I plan to follow for 6 weeks.) This is important to prevent gastrointestinal distress such as gas/bloating/diarrhoea/constipation. You must also drink plenty of water when consuming lots of fibre.
Pros of increasing fibre (prebiotic) intake
- I have felt much thirstier and as a result I have been drinking more water
- Fibre really fills you up – you might feel less hungry which should help with weightloss if this is a goal
- I have found I have increased energy after drinking my high-fibre smoothie
- Hopefully an improved gut microbiota – but results are not yet in!
Cons of increasing fibre (prebiotic) intake
- Initial gastrointestinal distress until your body adapts. Possible effects will be gas/bloating (which I did not experience), diarrhoea (I did experience), constipation (I did not experience)
- If you have gut dsybiosis then increasing fibre intake will feed all bacteria, both good and bad. This is not necessarily desirable and you may need to work on ‘weeding’ out pathogens before you add in prebiotics.
- Cost – buying the fibre supplements adds up and makes this quite expensive!
I will update this blog post once the results from my two Ubiome samples are in!