2,694,640 United States Patent Office Patented Nov. 16, 1954 1. 2 is characterized by the presence therein of the micro 2,694,640 organism. Lactobacillus bifidus as the predominating mi croorganism. The stools of infants who have been fed FOOD COMPOSITIONS exclusively with human milk are in fact remarkable in Paul György, Villanova, Pa., and Richard Kuhn and that this microorganism comprises practically the entire Friedrich Zilliken, Heidelberg, Germany, assignors, by bacterial flora present in the excretions. As seen in smears when freshly isolated from the mesne assigements, to American Home Products Cor infant feces the L. bifidus organism appears as gram poration, New York, N.Y., a corporation of Delaware positive, straight or curved rods that are non-motile and No Drawing. Application April 22, 1952, 10 that do not form spores. One or both ends may appear Seria No. 283,773 to be split longitudinally to give the effect of two short branches, this appearance leading to the term “bifid.' 4 Claims. (C. 99-54) shaped.One end of the organism may be bulbous or racket This invention relates to food products and, more par 5 While this microorganism predominates in the intes ticularly, to food products which are suitable for use in tinal tract and feces of infants fed with human milk from the feeding of infants. lactating mothers, it is not the characteristic or pre Our invention is more especially concerned with cer dominating microorganism in the intestinal tract of in tain new and improved food compositions which contain fants fed with other foods, such as cow's milk, or with the usual fat, protein, carbohydrate, fatty acid, amino 20 the commercially available food preparations derived acid, vitamin and mineral constituents necessary for from, or based on, cow's milk. Infants so fed show a growth of the infant, but which compositions also con less uniform intestinal flora with an appreciable propor tain, in addition, an added substance supplying a specific tion of gram-negative rods and cocci. factor or principle necessary to support the growth of The fact that a stable L. bifidus flora is characteristic the microorganism Lactobacillus bifidus as the predomi 25 only of the intestinal tract of breast-fed infants is now nant microorganism in the digestive tract of the infant fully understood and appreciated by pediatricians and fed therewith. other specialists in the medical, biological, and nutri There are a number of commercially available food tional Sciences. See, for example, the publications of compositions utilized for the feeding of infants which Tissier, Comptes rendus soc. biol., 51, pages 943-945; are based on cow's milk as an essential and important 30 and 60, pages 359-361; and Ann. inst. Pasteur, 19, pages nutritive constituent thereof. These compositions gener 109-123; and 22, pages 189-207. See also the papers ally contain, in addition to added vitamins, a fat con of Moro; Wien, klin, Wochschr.; 13, pages 114-115, and stituent, a milk protein, an edible Sugar (frequently lac Jahrb. Kinderheilk., 61, pages 687-734; and 61, pages tose), minerals, and ash. The relative proportion of 870-899. That the original observations of Tissier con these constituents is such as to provide a nutritive formula 35 cerning the predominance of L. bifidus in nurslings' stool meeting all the nutritional requirements of the infant have been amply confirmed is pointed out in the more when an aqueous solution of a specified concentration recent publication of Norris, Flanders, Tomarelli and is prepared and fed to the infant. Gyorgy in the Journal of Bacteriology, 60, pages 681-696 As an example, one well-known commercially avail (December 1950). able infant feeding formula, derived from cow's milk 40 Medical authorities are now in general agreement that but having major physical and chemical properties essen many of the advantages which a breast-fed infant seems tially the same as human milk, contains approximately to have, insofar as its nutrition and resistance to certain 1.5% of protein, 7.0% of carbohydrate, 3.5% of fat, diseases are concerned, are attributable, at least in part, 0.38% of ash and a mineral constituent, such as iron, to the predominance of L. bifidus in his intestinal tract. present in a relatively minor amount as, for example, 45 The prevalence of this organism in the intestinal tract approximately 0.0005%, as the food is made up as a is now believed to be of physiological significance, and liquid ready to feed to the infant. Such a composition its growth may prevent intestinal disorders caused by is, in many respects, similar to human milk, will supply other bacteria. Resistance to bacterial intestinal dis approximately 20 calories per fluid ounce, and contains eases, and even to parenteral disorders, such as respira of course, in addition, various vitamin constituents, such tory infections, is typical of breast-fed infants. Infants as vitamin A, thiamin, riboflavin, vitamin C, vitamin D who are bottle-fed with the milk of cows and other and niacin, all present (with the exception of vitamin C) animals, or with infant feeding formulas utilizing cow's in amounts considerably in excess of the amounts in milk as the source of protein, are definitely more sus which those vitamins are present in an equal volume of ceptible to such disorders. In this connection see the human or breast milk. 55 It should be understood, of course, that the particular article of Robinson in "Lancet,' entitled: "Infant Mor commercial food composition having the foregoing analy ity and Mortality,” vol. CCLX, page 788 (April 7, sis is but one of many available infant feeding formulas, In the infant colon in which a stable L. bifidus flora is all based on, or derived from, cow's milk, which com lacking it is now generally believed that the infant is positions are usually supplied, either in a concentrated 60 more likely to suffer from disorders attributable to the liquid form which is adapted to be diluted with water growth of other bacteria, some of which are harmful before use, or as a solid powder or granular composi to the infant, since competition for the available food tion which is dissolved in water in specified proportions supply in the infant intestinal tract where L. bifidus to provide solutions of specified concentrations. Such flourishes reduces the possibility that other bacteria, par compositions will vary to some extent from each other 65 ticularly the harmful B. coli, may grow in considerable in the ingredients utilized, i. e., the source of the fat numbers or in extensive colonies. In any event, where present therein, the content of saturated and unsaturated the gram-positive bacillus L. bifidus is present in large fatty acids and amino acids, the carbohydrate constituents, numbers in the infant intestine, which is now found the relative proportions of the ingredients, etc., but they only when the infant is breast-fed, there is considerably are essentially similar in that all are derived from the 70 less growth of other microorganisms, particularly of the milk of cows. gram-negative B. coli., the Clostridia, and certain air While some of these commercially available infant food borne microorganisms such as the Sarcinae bacteria. compositions are similar to human milk, to greater or While the reasons for the superior resistance to disease less degree, in their major physical and chemical prop of breast-fed infants as compared with infants who are erties, there are, however, certain important differences 75 fed on cow's milk, or on the usual infant formulas in in the predominating microorganisms present in the which cow's milk is a principal constituent, are not fully intestinal bacterial flora characteristic of an infant fed understood, pediatricians are generally agreed that in exclusively with human or breast milk, as compared with some measure, at least, the superior resistance is at the intestinal flora of an infant who is fed with one of tributable to the presence of an extensive L. bifidus flora the commercial food formulas based on, or derived from, 80 in the intestines of nurslings, this bacterium being absent cow's milk. The intestinal flora of the breast fed infant in any considerable numbers from the intestines of in 2,694,640 3 4 fants who are not fed with human milk. Interest in erably by treatment with a strong mineral acid, to yield the isolation and determination of the growth require the hydrolyzed product found to possess Lactobacillus ments of L. bifidus has therefore been stimulated by bifidus growth-promoting activity. its apparently unique predominance in the intestinal tract For example, lobster shell may be first treated, pref of the breast-fed infant. erably for one or two days, with a caustic solution such Extensive research work has been carried out on the as a ten percent solution of sodium hydroxide. After identification and isolation of the active biological prin the caustic treatment the lobster shell is subjected to the ciple which is responsible for promoting the growth of action of a mineral acid, such as hydrochloric acid of L. bifidus in the intestines of infants who are nourished about 5% concentration, for a period of one or two with human milk, which active principle is evidently not O days, at the end of which a skeletonized product is secured present in sufficient amount to insure the growth of L. which is practically pure chitin. bifidus as the predominant microorganism in the intestinal The chitin is first hydrolyzed, preferably at room tem tract of infants who are fed with cow's milk, or with perature, by treatment with a strong mineral acid, such any of the usual feeding compositions or infant formulas as Sulfuric acid of approximately 50% concentration, based on cow's milk.