Diets for Re-balancing the Gut Flora in Allergy
Re-balancing the Gut Flora
The gut flora are a large collection of bacteria and yeasts living, usually without harmful effects, in our intestines. Some of these microbes are acquired by a baby during birth - several of the most useful kinds live in the vagina too, and the baby swallows them en route to the outside world. Recent research shows that babies delivered by Caesarean section take much longer to acquire the normal gut flora. However, they catch up eventually because, like other babies, they pick up bacteria in the months immediately after birth, mainly from the mother.
There are hundreds of different kinds (species) of microbe in the gut flora, with the exact mix varying from one person to another. They eat the remains of our meals, and provide certain benefits in return:
• they make some useful vitamins that we can then absorb
• they keep disease-causing bacteria at bay simply by being there, taking up all the potential ‘parking spaces’ on the lining of the gut so that alien bacteria can’t find a foothold
• they may also aid digestion in some way, although this is less certain.
On the downside, the gut flora also produce toxins, but we have had aeons of evolution to get used to these, and the liver normally breaks them down quite happily. Only if the liver is badly diseased (as in cirrhosis) do these toxins become a problem.
The immune system is familiar with these fellow-travellers and tolerates them, while ensuring that they do not invade the body any further. However, a loss of immune competence, as in AIDS, can allow them to become invasive and cause disease.
Research into the gut flora is a relatively new field of medicine, and most of the studies have been published in rather obscure medical journals. So the majority of doctors are unaware that abnormalities of the gut flora – the increase of some species at the expense of others – have been found in patients with rheumatoid arthritis, atopic eczema, irritable bowel syndrome and Crohn’s disease. The relationship between these abnormalities and the disease process is unclear at present: it is not necessarily
a cause-and-effect relationship. The implications, as far as treatment is concerned, are far from clear as yet.
The controversial condition known as ‘candidiasis’ appears to be a particular form of gut-flora imbalance, in which yeasts are overly successful. It is called yeast overgrowth in this book (see p. 82).
Among the factors that can cause an imbalance in the gut flora are:
• prolonged or repeated treatment with antibiotics; also a single high-dose treatment, as may be given before a hysterectomy operation (see p. 76). These seem to kill off the beneficial bacteria in the gut flora, allowing others to flourish.
• severe diarrhoea, which can deplete the normal community of bacteria. Usually the effect on the gut flora is temporary, but it can sometimes be long-lasting and may lead to food intolerance (see p. 76).
Additional factors that might contribute to a disturbed gut flora are:
• a diet that is high in sugar and refined carbohydrates; this is thought to give yeasts an unfair advantage over other members of the gut flora, by providing yeasts with their preferred food
• taking the contraceptive pill; this is very controversial, but some doctors believe there is a link between the widespread use of the contraceptive pill and the number of cases of suspected yeast overgrowth in young women.
Bacterial replacers or probiotics
Bacterial replacers, also known as probiotics, supply live bacteria to replenish the gut flora with favourable species.
Experimental trials suggest that taking bacterial replacers may be a useful treatment for irritable bowel syndrome, for food sensitivity in babies, and for atopic eczema (including prevention – see p. 243). This approach may also be of value in yeast overgrowth, when combined with dietary treatment (see below).
All bacterial replacers have to be taken every day: the bacteria do not seem to establish themselves permanently in the gut flora. And any benefits from taking them vanish within a few days of stopping the treatment – so this is quite an expensive option.
Unless the bacteria in the product are alive – and alive in considerable numbers – the bacterial replacer is of no value. Refrigeration is the key to keeping the bacteria alive since, after three days at room temperature, their numbers start to decline steeply. Bacterial replacers purchased from a health-food shop may have been stored at room temperature for some time and so contain very few live bacteria. Buying by mall, directly from the supplier, is a good plan: ask how long the delivery usually takes.
Many different brands of bacterial replacer are now available. To locate companies selling by mail order, see p. 255.
The no-yeast-no-sugar diet
Although this diet has not been tested scientifically, it is widely used by doctors who are interested in gut-flora disturbances, and often produces strikingly good results with people who had previously intractable health problems. This is not hard scientific data, but the impressive results with certain patients (see p. 82) suggest that the diet is sometimes worth trying. Those with symptoms ascribed to yeast overgrowth or ‘candidiasis’, especially bowel problems and an itchy anus (see p. 82), benefit most frequently.
The best way to do this diet is to start with a relatively low-key approach (Stage 1). Only progress to more stringent dietary measures if you don’t improve adequately. If there is no improvement at all, even on the Stage 4 diet, then you can be reasonably sure that yeast overgrowth is not the cause of your problems.
Stage 1
If you are taking the contraceptive pill, talk to your doctor about changing to another form of contraception. Although the link between yeast overgrowth and the pill is not in any way established, stopping the pill often seems to be beneficial.
Cut out sugar and all sweet foods, including honey, syrup, jam, chutney, pickles, cakes and biscuits, soft drinks and fruit squash. Note that ‘no-added -sugar’ jam should also be excluded – it is very rich in fruit sugars. Also avoid dried fruits, and change
any medicines taken as syrups to tablet form. Do not eat peanut butter, tinned sweetcorn or baked beans, except sugar-free brands. Avoid sweet potatoes, and any vegetables that become sweet when cooked e.g. baked parsnips, caramelised onions. Your ’sweet tooth’ should be your guide – if it tastes sweet, it’s off the menu. Only artificial sweeteners are allowed.
Not eating sugar is thought to deprive the yeast of much of its food supply. Persist with this diet for 4-6 weeks. If you are no better, or only partially better, go on to Stage 2.
Stage 2
In addition to the restrictions of Stage 1, cut all fruit out of your diet, except for pure, unsweetened lemon juice and lime juice. These juices, plus salads and lightly cooked vegetables, should give you enough Vitamin C – or you could take a supplement.
Cut out white bread and anything made with white flour (e.g. pancakes, pastry, noodles and other pasta). Small servings of wholemeal bread, potatoes and unpolished rice (’brown rice’) are allowed. Your staple diet should be vegetables and high-protein foods such as meat, fish and eggs.
Do eat herbs, spinach and fresh garlic, as these may help to curb the growth of yeast. Don’t eat cheese or anything fermented.
Stick with this diet for at least four weeks, and longer if you begin to feel partially better. If you feel a lot better, continue for several weeks, then gradually reintroduce fruits and other excluded foods – but not sugar, honey, jam, syrup or any other very sweet foods.
Stage 3
In addition to all the restrictions of Stages 1 and 2, cut out any foods containing yeast (see p. 190). Why this should work is not entirely understood (see p. 83).
A response to this diet, even a partial response, is a good sign. Consider going on to Stage 4.
Stage 4
Your doctor must agree to you trying this diet, as it may not be safe for everyone.
Avoid all starchy foods including bread, flour, potatoes, rice, pasta, cornmeal, parsnips, beans, lentils etc. Nuts can be eaten in small quantities, but not cashew nuts. This is an extreme diet which gives the yeast almost nothing to live on. No one should stay on this diet for more than a few weeks: it is only used to confirm the diagnosis, or to get the problem under control before tackling it with other treatments.
If there is any improvement with the Stage 4 diet, talk to your doctor about anti-fungal drugs (see p. 83).