The human immune system is designed to protect the body from external factors. Its selective mechanisms are very important to the human body, since it is an integrating system communicating with the nervous and endocrine systems.

The immune system is formed in fetal life, and then it develops throughout childhood and reaches full maturity around the age of 12. Its proper function depends on environmental factors, the most important of which is nutrition that should provide vitamin C. Previous studies have found that vitamin C plays a significant role in the structures of the immune system, which is associated with its high concentration in phagocytes and lymphocytes, exceeding the levels recorded in the plasma.

The digestive tract is the largest organ in the immune system and it is easily affected by pathogens.

The study of parasites, the organisms that live on or in the host, deals with their biology, occurrence and spread. It also analyses the course of parasitic diseases and develops the methods of their treatment and prevention. Parasitism is an antagonistic relationship in which the individuals of one species benefit at the expense of the individuals of another species, treating them as food and habitat. In this way a population is harmed. Interactions make the host’s population grow slower. The human body may harbor over 300 kinds of parasites. It is commonly believed that they only occur in intestine but the truth is they may live in any part of the body.

Statistical analysis showed that about 2 billion people is infected with at least one parasite, while the overall number of parasitoses exceeds 3 billion. According to WHO, over the last 10 years, more than 4.5 billion people got infected with different kinds of parasites. In the USA this number is 85-95%, while in Europe every third person is infected with a parasite. This induces an assumption of a possible 25% death rate. The recent study shows that in 95% of adults one to five species of parasites could be found. The human body can harbor both microscopic parasites and the ones visible to the naked eye.

Problems related to the occurrence of parasites in the human body are recurrent, and even in the 20th century, parasitic diseases become more common. Deeper knowledge about parasites, improvement of sanitary conditions and better preventive measures seem not enough.

The factors affecting a proper function of the defense mechanisms include genetic predispositions, age, health condition, stress and a diet. Out of the dietary components which display immunological effects and that can be found in the DuoLife products, those with immune modulating potential have been selected. Proper care for the condition of the immune system make the infections less frequent and milder.