"Grow" prebiotics to "feed" probiotics - or how gardeners and growers can re-energise the wholefood movement
by Hans Wieland
Do probiotics ever sleep? I was thinking about that recently, because I eat raw garlic. Whole peeled cloves! Five of them with a piece of sourdough and a pinch of salt! In the evening! Around midnight, before I got to bed. Puzzled? Read on!
Fermented foods contain beneficial probiotic bacteria
Fermented foods are trendy in Ireland. No weekend goes by without a new take on kimchi published in the food supplements of the weekend papers. Trends come and go, but the real challenge in Ireland is incorporating fermented and cultured food into everyone’s diet. My wife Gaby and I have been giving courses on fermented foods since our arrival in Ireland in 1985, quietly trying to convince people about the many benefits of fermentation from preserving food to health benefits and creating exquisite and exiting flavours. Our mission was and still is to pass on skills, knowledge and recipes, so that fermenting foods can become part of everyone’s daily life. If riding on the trend helps us to make more people aware of the wonderful world of beneficial bacteria, all the better. And we have been joined by many other wonderful fermentistas on our journey.
In my article Operation Fermentation in the Autumn 2016 edition of GROW I have highlighted the importance of probiotics in fermented foods. Here I will make the connection to prebiotics.
It’s an interesting fact and more than coincidence that garlic, the vegetable that started GIY is one of the best prebiotic foods, it is even more assuring that many thousands of gardeners grow prebiotic foods without much being aware of it. Finally, eating organic whole foods rich in fibre (carbohydrates) is as important for your gut health as consuming fermented foods.
But first things first!
“Grow” prebiotics to “feed” probiotics!
Probiotics and prebiotics both serve important health functions for our digestive system in
the human gut.
Probiotics are live microorganisms that live inside your gastrointestinal tract. They aid in digestion by essentially cleaning out the gut so that things keep flowing. Like all living things, probiotics need to be fed in order to remain active and healthy and to benefit us as much as possible.
Prebiotics are types of dietary fibre that feed the friendly bacteria in our gut. Prebiotics act as food for probiotics. In other words, probiotics eat prebiotics. This helps the gut bacteria produce nutrients for our colon cells and leads to a healthier digestive system’. In a nutshell, prebiotics are a type of un-digestible plant fibres that can only be eaten by nice bacteria. The more food or prebiotics that probiotics have to eat, the more efficiently these live bacteria work and the healthier our gut will be.
The health benefits of prebiotic food
Higher intakes of prebiotics are linked to many health benefits:
· lower risk for cardiovascular disease
· healthier cholesterol levels
· better gut health
· improved digestion
· lower stress response
· better hormonal balance
· higher immune function
· lower risk for obesity and weight gain
· lower inflammation and autoimmune reactions
The importance of fibre in prebiotic foods
Talking about plant fibre in prebiotic foods there are two important ones, which occur naturally in many healthy foods: Oligofructose and Inulin. Together they fertilise Bifido and Lactobacilli, the healthy bacteria that live throughout the colon.
Fructooligosaccharide (FOS) is a simple carbohydrate and soluble fibre that is immediately fermented when it enters the colon in the right lower side of the abdomen down by the appendix. Inulin is a more complex soluble fibre that takes much longer to ferment and is more available to the bacteria that reside in the rest of the colon, mostly on the left side. Other important nutrients in prebiotic foods are fatty acids that can be absorbed into the bloodstream and improve metabolic health.
What are the best prebiotic foods?
Since fibre is the source for prebiotics, foods that are high in fibre are also typically high in prebiotics. Everyone seems to have his own version of the Top 10 Foods Containing Prebiotics or 7 Reasons to get Prebiotics in your Diet or 14 Prebiotic Foods you should be eating or 18 prebiotic rich foods for a gut friendly diet.
Here are some of my top contenders on the prebiotic foods list:
1. Chicory Root, popular for its coffee-like flavour and a replacement for coffee, is a great source of prebiotics., because nearly half of chicory root fibre comes from Inulin.
2. Dandelion Greens are a great fibre-rich substitute for greens in your salad or a spicy addition, containing 4 grams of fibre per 100 grams serving with a high portion of Inulin.
3. Jerusalem Artichokes have been shown to increase the friendly bacteria in the colon even better than chicory root, providing about 2 grams of dietary fibre per 100 grams, 76% of which comes from inulin. Jerusalem artichoke can be eaten cooked or raw.
4. Garlic and Onions not only give great flavour to our foods but provide us with prebiotics. About 11% of fibre content comes from Inulin and 6% from the FOS. Leeks provide even more inulin, up to 16%.
5. Asparagus is another great source of prebiotics and also protein. The inulin content may be around 2-3 grams per 100-gram serving.
Bananas, barley, oats, cocoa, flaxseed and seaweed are all excellent sources of dietary fibre besides vitamins and minerals. Apples are very high in pectin fibre (50%). Burdock root commonly used in Japan is another interesting prebiotic plant. It has been shown to promote healthy bowel movements, inhibit the formation of harmful bacteria in the colon and boost the immune system. Yacon Root is particularly rich in prebiotic fructooligosaccharides (FOS) and inulin.
Probiotics love Prebiotics and Prebiotics love Gardeners
As gardeners and growers we are in a very powerful position if it comes to gut health. We can grow the best prebiotic foods ourselves to feed the probiotic bacteria in our gut.
“Since bacteria are so much smaller than we are, they view food from as very different perspective from our own. Every little grain becomes a major event, a comet of deliciousness. Food we cannot digest in the small intestine is called dietary fibre or roughage. But, despite the name, it is not rough on the bacteria of the large intestine. Quite the opposite, in fact: they love it! Not all kinds, but some, anyway. Some bacteria love undigested asparagus fibres; others prefer undigested meat fibres.” (Guilia Enders, Gut, the inside story of our body’s most under-rated organ, Scribe 2015)
If it comes to prebiotics not all vegetables are the same and probiotics are choosy! Probiotic bacteria, namely bifidobacteria and lactobacilli, especially love vegetables from the onion family (garlic, onion, leeks, chives, scallions) and the daisy family (Jerusalem Artichoke, globe artichoke, chicory, endive and lettuce and scorzonera), vegetables rich in their preferred foods: Inulin and Fructooligosaccharide.
They also love potato skins, organic apple cider vinegar and bananas. And they like resistant starches that form when potatoes and rice are boiled and left to cool. No wonder they love Hans and Gaby’s favourite prebiotic dishes: Potato salad and Sushi. Naturally probiotic bacteria love whole-grain and sprouted-grain breads. Important to note is the fact that raw is best, because if you cook vegetables you lose some of that precious prebiotic fibre.
How do I get prebiotics and how much?
While there is no broad consensus on an ideal daily serving of prebiotics, recommendations typically range from 4 to 8 grams per day. Given a recommended average 6 grams per day, below are the amounts of some prebiotic foods required to achieve a daily serving of prebiotic fibre:
6 cloves of garlic (35grms), 1 raw onion (70g) or 120g of cooked onion, 9.3 grams chicory root, 19 grams Jerusalem Artichoke, 24.7 Dandelion Greens, 51grams leek, 120 grams Asparagus, 600 grams Bananas.
Grow it yourself for health: Classic Vegetables for Fermentation
If you want to grow vegetables for preserving using the fermentation method, here are my classic vegetables varieties:
· Cabbage: Filderkraut for sauerkraut
· Winter cabbage: January King and Dottenfelder for sauerkraut and storage
· Red cabbage: Rodynda
· Spring cabbage: Pixie and Hispi
If you want to make a lot of Kimchi you can grow your own Chinese cabbage. The best varieties are: Jade and Pagoda, a cylindrical type. Also great for Kimchi are radishes especially Moolie or Daikon varieties.
Beetroot is great for making Kvass and my favourite varieties are: Detroit Globe (dark red), Boltardy (early variety), Jannis (very good for the Winter), Barbietola di Chioggia and Cylindra.
And I strongly believe that every garden should have a Horseradish plot.
Grow it yourself for health: Classic Prebiotic Vegetables:
As you can see from my top contenders on the prebiotic food list, many are very easy to grow and belong to the onion family: Garlic, onion, leeks, chives and scallions. Maybe not so well known are the members of the daisy family: Jerusalem Artichoke, globe artichoke, chicory, endive and lettuce and scorzonera. Give Jerusalem and Globe artichokes a permanent bed in your garden and you will be richly awarded. Endive and chiocory are fantastic salad plants throughout the Winter month and deserve to be grown more. And then there is one of my favourite “unusual” vegetables Yacon. I grow it in the polytunnel with great success and good yield. It tastes best raw, grated in a salad with carrots.
Burdock and dandelion are often seen as weeds and are treated like the worst enemies, but I believe they deserve a place in our garden, wild or cultivated.
Do yourself and your gut bacteria a favour by growing and eating plenty of these prebiotic foods. I think I am pretty much covered growing and eating as much garlic as possible. Remember my daily night time binge of raw garlic provides me with the recommended daily intake of prebiotics.