Yeasts in foods and intestinal flora
Alquanto popolare tra i fautori di varie medicine alternative, praticamente assente nei libri di testo della medicina ufficiale, stiamo parlando dell’intolleranza ai lieviti, espressione generica per indicare una disbiosi della flora intestinale con sovracrescita della componente fungina, in particolare del lievito Candida albicans. Iniziamo col dire che spesso i termini funghi e lieviti sono utilizzati come sinonimi, dal momento che i lieviti rappresentano funghi unicellulari di dimensioni microscopiche. Oltre al genere Candida, nella flora batterica intestinale dell’uomo si riscontrano anche funghi appartenenti al genere Saccharomyces, Aspergillus and Penicillium . Analyzing the metabolism of these mushrooms in detail, we realize how the ideal environment for their proliferation is generally particularly rich in sugars or more complex carbohydrates , which reach the colon through food residues not absorbed at the level of the small intestine .
La flora batterica intestinale può essere considerata una sorta di impronta genetica, diversa da individuo ad individuo e influenzata soprattutto dalla dieta, che tende a favorire alcune specie microbiche rispetto ad altre. Molto importante, in tal senso, risulta la funzionalità dell’apparato digerente che – a parità di dieta – può diversificare la quantità di nutrienti inassorbiti o mal digeriti che giungono nel colon. Anche alcuni farmaci, primi fra tutti gli antibiotici, i corticosteroidi e le terapie ormonali (pillola anticoncezionale, terapia sostitutiva orale), possono interferire con la flora microbica generando quadri di disbiosi.
Although the alterations of the intestinal microbial flora find limited space in the textbooks of official medicine, more and more experts and empirical experiences hold them responsible for disorders that are not all in all disabling, but rather widespread in industrialized countries: from food intolerances to imbalances in the immune system and related consequences (increased susceptibility to infections, allergies , autoimmune diseases , etc.), from fungal diseases (particularly candida ) to bowel disorders ( diarrhea , constipation , meteorism , flatulence, abdominal cramps etc.), from genital and urinary infections to nutritional deficiencies (especially vitamins and minerals ), from the predisposition to colorectal tumors to low physical efficiency, with migraine and a sense of weakness.
Yeast intolerances: a personal matter…
When faced with the aforementioned ailments, food intolerances are very often brought up, which are very fashionable today and are often overestimated, sometimes confirmed and corroborated by diagnostic tests of dubious utility or completely unreliable. As often happens, we start from established scientific assumptions (those listed in the introductory part) and then get lost in simplistic reasoning reaching completely misleading conclusions. Let’s think, for example, of brewer’s yeast , the undisputed protagonist of the leavening of bread and bakery products ; the microorganisms that constitute it ( Saccharomyces cerevisiae) ferment the glucose of the bread producing the carbon dioxide necessary to make it leaven; here then that in the face of symptoms such as a swollen belly, meteorism and excess intestinal gas , it is easy to blame an intolerance to yeasts. In reality, the factors called into question are innumerable and must be carefully studied to find a solution to this disorder ( lactose or gluten intolerance , poor digestive efficiency, overeating in a sedentary context, excessive consumption of carbonated drinks , low or excessive consumption of fibers , digestive intolerance towards particular combinations of foods, aerophagiaand so on). Often, however, there is a tendency to prescribe pre-printed diets that eliminate certain categories of foods. For example, if an intolerance to yeasts is “diagnosed”, often at the hands of subjects who boast skills and qualifications never achieved, the following tends to be imposed:
- the avoidance of sugars, alcohol and foods rich in yeasts and mycotoxins . For this reason, at the top of the “black list” we find sucrose , fruit (both sugary and dried), most cereals , sugary and alcoholic beverages (especially beer ), smoked foods or foods rich in preservatives , peanuts , vinegar , bread ( admittedly unleavened) and hard cheeses . On the other hand, the candida diet encourages the consumption of yogurtunsweetened (as a food rich in bacteria useful for intestinal health), specific probiotic and prebiotic formulations, garlic , turmeric and various fermented foods such as miso or kefir . Allow fish , eggs , lean meat , olive oil and other seed oils , brown rice , algae and vegetables (well washed).
- The anti-candidal diet gives a lot of space to some supplements , such as the aforementioned probiotics (especially bacteria of the Lactobacillus genus ), prebiotics ( FOS and inulin ), caprylic acid , sorbic acid and sorbates , and supplements based on soluble fibers ( pectin , rubber guar , psyllium and flax seeds ).
- Other times, all fermented foods are eliminated from the diet altogether.
In reality, rather than providing pre-printed diets or abolishing certain categories of food out of the blue, in the face of a presumed yeast intolerance it would make much more sense to educate the subject to a healthy lifestyle and to respect a series of food standards of general character particularly useful in case of symptoms attributable to dysbiosis; for example, it is advisable to evaluate whether there is an improvement in symptoms:
- severely limiting the consumption of milk and dairy products for a few days;
- severely limiting the consumption of leavened baked products for a few days (bread, crackers , breadsticks , rusks , biscuits, sweets, pastry products…);
- severely limiting the consumption of carbonated and fermented drinks ( wine , beer, spirits in general, black tea );
- strongly reducing the consumption of food for a few days (see purifying diet ) in order to give the digestive system – overloaded by too much work – the time necessary to rebuild its enzymatic pool; possibly after this phase, start consuming probiotics (consult your doctor);
- chewing foods for as long as possible before swallowing them, consuming one’s meals in a serene and comfortable environment: “setting down the cutlery” with each bite;
- consuming small and frequent meals, rather than concentrating a large part of food intake at lunch and dinner;
- preferring simple cooking methods ( steamed , in a non-stick pan with a little oil) to the more laborious ones ( frying , grilling , various sauces…);
- increasing physical activity , especially for sedentary people;
- adopting the main rules of the dissociated diet , particularly useful in case of dyspeptic symptoms attributable to “food intolerances” in general: do not combine protein-rich foods with carbohydrate -based foods within the same meal , especially if rich in sugars ; avoid combining protein sources of different nature (for example meat and fish or legumes and dairy products); eat complex carbohydrates and sugars in separate meals; abandon the classic habit of concluding the meal with fruit and/or dessert; it is better to consume these foods alone and at different times of the day.
