Food intolerances (food intolerances) occur from congenital or acquired enzyme deficiencies or defects. The consequences can be disorders of the processes in the gastrointestinal tract (maldigestion), whereby food can no longer be broken down into its absorbable components, or can only be broken down inadequately.Functional failures of the intestinal mucosa, disorders of the absorption of the already broken-down nutrients and vital substances from the inside of the intestine, or disorders of the onward transport through the intestinal cell membrane into the organism – resorption disorders, malabsorption – are also frequently the leading symptoms of an enzyme deficiency. In malabsorption, the small intestine is no longer able to transfer water, vitamins, minerals, trace elements and cleavage products of complex carbohydrates into the blood and lymph channels with the help of special transport systems. Maldigestion,malabsorption as well as a variety of symptoms of metabolic diseases lead to an impairment of food utilization (malassimilation) and thus to a subnormal supply of nutrients and vital substances (macro- and micronutrients) as well as occurrence of non-utilizing macro- and micronutrients and non-absorbed bile acids in deeper intestinal sections.Leading symptoms are:
- Increased fat excretion with the stool due to maldigestion in the absence of the enzyme lipase – fat diarrhea (steatorrhea).
- Progressive weight loss despite usually good appetite and abundant food intake.
- Local irritation symptoms
- Changes in the intestinal flora (dysbiosis)
- Germ colonization of sections of the small intestine
- Exposure of the mucosa of the small intestine to more or less toxic metabolic products
- Flatulence or bloating (flatulence).
- Disorders of fluid absorption – watery diarrhea (diarrhea).
Common clinical symptoms of deficiency in general malnutrition include:
- Complete depletion of storage fat depots, muscle proteins, and building fat (adipose tissue that serves as a structural component, for example, mechanical protection, padding, or organ storage), as well as tissue atrophy with a gradual loss of organ function – weight loss, cachexia
- Muscle atrophy, weakness and involuntary muscle twitching – muscle atrophies.
- Anemias (anemia)
- Osteoporosis (bone loss), bone softening and deformation (osteomalacia).
- Skin changes as well as diseases, rough and itchy skin – pellagra-like skin eczema.
- Diarrhea (diarrhea) and loss of appetite – pellagra-like mucosal manifestations.
- Increased keratinization of the surface of the organ tissue.
- Blood clotting disorders
- Disease of the nerves affecting the affected organs, such as tingling and numbness of the extremities, cardiac arrhythmias, hypertension (high blood pressure), disorders of the digestive tract.
The clinical consequences of inadequate macro- and micronutrient utilization (nutrients, vital substances) depend on the nature, extent and duration of the disorder.
In contrast, utilization disorders that affect only the utilization of individual food components – for example, fructose and lactose – have symptoms that correspond to the deficiency of the non-utilizing vital substance (micronutrients).