This is the time of year when the tall stalks of the Jerusalem artichokes are dying back and their edible roots are dug up. If you haven’t eaten this vegetable since last year, prepare yourself for some unfortunate bowel events! The flatulence and sometimes diarrhoea that this vegetable cause is enough to make many veer clear of it! This is a real pity as they are so good for you. The solution to the problem lies in introducing it to your diet gradually - rather than having a whole plate full one night for your dinner after not having it for a whole year!
After the initial uncomfortable bowel disturbance, they will beneficially disturb you bowels, as they actually feed the very important good bacteria in your bowels! The two most well-known prebiotics are FOS and Inulin. These are plant fibres found in abundance in Jerusalem artichokes and chicory root, and in (approximate) descending order in leeks, onions, salsify, garlic, bananas, fruit, asparagus, oats, whole rye and whole wheat. It is important that the foods are fresh, otherwise, the inulin breaks down in the plant into sugars - the fresher the vegetable the higher the inulin content. Inulin is actually the plants equivalent of fat, they accumulate it when there is plenty of solar energy and use it as fuel when the skies are dark or overcast. The acids (acetic and butyric acid) produced by the well-fed good bacteria inhibit the growth of bad bacteria.
As a result the balance of bowel bacteria tips in a healthy direction. Prebiotics have other benefits too. They are antagonistic to some disease-producing bacteria such as salmonella, listeria and campylobacter, and the acids that the probiotics produce smooth out blood sugar levels, discourage the body from laying down fat and they stimulate the immune system.
Unfortunately, there are downsides to everything! As previously mentioned, in some people they may cause flatulence, and if very large amounts are taken, diarrhoea. FOS is more likely to cause problems than inulin. If onion, leek or Jerusalem artichoke soup causes bowel discomfort for you, you need to start eating these foods gradually. Starting in small doses will soon cause the initial problems to subside – once the new colonic regime becomes established!