Absorption of Undigested Proteins in Human Beings

Abstract

It has been shown in previous communications 1 that following the ingestion of such proteins as those of fish and eggs, detectable amounts of these substances are absorbed into the circulation in most normal adults. Absorption from the rectum was also demonstrated by the same technic.1c The present communication deals with an investigation of these phenomena of absorption in infants and children.Egg was chosen as the protein most suitable for study because it is a common constituent of the diet of the average child and is easily administered. The technic employed in this investigation was practically the same as that reported in the previous communications. A brief summary follows : METHODS OF INVESTIGATIONEgg in any form was excluded from the diet of the subject on the day that passive local sensitization was induced. This procedure consisted of an intracutaneous injection into the flexor surface of the forearm of about 0.05 cc. of a special serum obtained from a person who was sensitive to eggs (K 4 serum). On the following morning the test meal, containing egg, was taken by the fasting subject. No attempt was made to clear the intestinal tract before the test. Follow¬ ing the meal, the sensitized cutaneous site was kept under observation. The appear¬ ance of erythema or a wheal marked the onset of the local reaction, which indicated that unaltered egg protein had entered the circulation.The 4 serum used for producing passive local sensitization was the same as that employed in the series of adults. It was obtained from a patient 2yí years of age, suffering from eczema, asthma and urticaria, who was extremely sensitive From the Jewish Hospital.

Allergens in Atopic Dermatitis

“…However, some studies demonstrated ingested food antigens could penetrate the digestive tract barrier and were transported in the blood stream to mast cells in the skin [17,18]. The first murine model of an AD-like disorder induced by oral sensitization with a food protein has been established in 2001 [19].…”

Delayed-Onset Food Allergies

“…In the 1920s, reactions to food were linked, via experiment s, to such phys ic al sy mptoms as colitis, diarr hea , bla dd er pain , and Meniere 's syndrom e. 8,9 Other experiments were performed, demonstrating the ability of ingested food antigens to penetrate the GI barrier and become affixed to dermal mast cells. 10,11 Food allergie s other than type I were describ ed in the 1930s, with reports of delayed symptoms of hours to days following the ingestion of suspect foods. 12…”

Protein Delivery

“…Despite all of the above obstacles to peptide and protein absorption, there is both clinical and experimental evidence that large molecules may penetrate the intestinal mucosa (Gruber et al, 1987). The degree of this macromolecular absorption is certainly not of any nutritional significance but still is often high enough to be of biological importance (Alpers and Isselbacher, 1967;Bernstein and Ovary, 1968;Bockman and Winborn, 1966;Casley-Smith, 1967;Chisui, 1968;Cornel1 et al, 1971;Danforth and Moore, 1959;Walker et al, 1972;Warshaw et al, 1971), and such macromolecular absorption has been observed to occur under normal physiologic conditions (Gruskay and Cooke, 1955;Korenblat et al, 1968;Wilson and Walzer, 1935). Adults, for example, develop precipitins in serum following ingestion of milk proteins (Korenblat et al, 1968).…”