CA2822892C - Method for inhibiting pathogens using a nutritional composition - Google Patents

Abstract

A method for inhibiting a bacterial invasive or adhesion mechanism involving administering to a human a nutritional composition including a lipid or fat; a protein source; a prebiotic composition; and at least about 10 mg/100kCal of lactoferrin produced by a non-human source.

Description

DESCRIPTION
METHOD FOR INHIBITING PATHOGENS USING A NUTRITIONAL
COMPOSITION
TECHNICAL FIELD
[0001] This disclosure relates generally to the field of nutritional compositions, such as infant formulas, human milk fortifiers, children's dietary supplements, and the like, having lactoferrin compositions therein. More particularly, the disclosure relates to a method for inhibiting the invasive mechanisms of harmful bacterial pathogens and/or inhibiting the adhesion of at least one pathogen in a human gastrointestinal tract by administering to the human a nutritional composition including lactoferrin produced by a non-human source.
BACKGROUND ART

[0002] There are currently a variety of dietary compositions for humans, especially young humans, to provide supplemental or primary nutrition at certain stages in life. Generally, commercial dietary compositions for infants seek to mimic to the extent possible the composition and associated functionality of human milk.
Through a combination of proteins, some of which have physiological activity, and blended fat ingredients, dietary compositions are formulated such that they simulate human milk for use as a complete or partial substitute. Other ingredients often utilized in dietary compositions for infants may include a carbohydrate source such as lactose as well as other vitamins, minerals and elements believed to be present in human milk for the absorption by the infant.

[0003] Some of the proteins present within human milk provide for a defense against pathogens to prevent and inhibit infection while additionally promoting an immunological response within the infant. Proteins including haptocorrin and lactoferrin are understood to help infants defend against a variety of bacterial pathogens via bacteriostatic and bactericidal activity.

[0004] Lactoferrin is one of the primary proteins in human milk and is considered a glycoprotein having an average molecular weight of approximately kilodaltons. It is an iron binding protein having the capacity to bind two molecules of iron in a reversible fashion and can facilitate the uptake of iron within the intestines for the human. Functionally, lactoferrin regulates iron absorption and as such can bind iron-based free radicals as well as donate iron for an immunological response.

[0005] An additional role of lactoferrin is its anti-microbial activity in guarding against intestinal infections in humans generally, but especially in infants. Lactoferrin has been known to be both bacteriostatic and bactericidal in inhibiting the growth of specific bacteria while also killing microbes prior to a successful invasion of intestinal cells.

[0006] In obtaining a commercially viable dietary composition, the addition of lactoferrin has generally been limited due to predicted losses of activity during processing. For example, generally, the temperature and pH requirements in processing infant formulas and other products such as human milk fortifiers and various children's products reduce specific functions of the lactoferrin, causing lactoferrin not to be included within a final formulation. In addition, lactoferrin is often considered only for its iron binding qualities; thus, lactoferrin may generally be excluded from a formulation where such properties are thought to be diminished by processing conditions.

[0007] Further, as known in the art, human breast milk is relatively low in iron, containing about 0.3 milligrams of iron per liter of breast milk. While this quantity is low, human infants have high absorption rate, absorbing about half of the iron from the breast milk. However, when human infants are fed prior art formulas with high levels of iron fortification, e.g. from about 10 mg to about 12 milligrams per liter, the infants absorb less than about 5% of the total iron.
With such increased levels of iron within the prior art formulas, virtually all of the lactoferrin iron binding sites would be expected to be occupied, as lactoferrin is a known iron transport protein.

[0008] Additional complications of the prior art formulas include the inability of providing a bacteriostatic effect. This is partially due to the use of lactoferrin with blocked or damaged binding sites as the bacteriostatic effect is at least partially related to the degree of binding to iron of the lactoferrin present within the formula.

[0009] Accordingly, it would be beneficial to provide a nutritional composition, such as an infant formula, human milk fortifier, children's dietary supplement, and the like, which contains lactoferrin, in particular, lactoferrin produced by a non-human source. Preferably, the lactoferrin included in the compositions has a bacteriostatic effect even after processing under conditions of high temperature and low pH. A combination of characteristics including the maintenance of the anti-invasion or anti-adhesion mechanisms of lactoferrin through either high or low pH or high temperature conditions, such as during pasteurization, provide for a dietary composition that may at least partially protect against harmful bacterial pathogens.
DISCLOSURE OF THE INVENTION

[0010] Briefly, the present disclosure is directed, in an embodiment, to a method for inhibiting one or more of the invasive mechanisms of a bacterial pathogen and/or the adhesion of at least one pathogen using a nutritional composition comprising a lipid or fat, a protein source, a prebiotic composition, and lactoferrin from a non-human source, where the composition provides active anti-invasion and anti-adhesion mechanisms against strains of undesirable bacteria found in the human gastrointestinal tract, even after processing which includes exposure to harsh environmental conditions.

[0011] In an embodiment, the disclosure is directed to a nutritional product comprising:
a. up to about 7 g/100 kcal of a fat or lipid, more preferably about 3 g/kcal to about 7 g/100 kcal of a fat or lipid;
b. up to about 5 g/100 kcal of a protein source, more preferably about 1 g/kcal to about 5 g/100 kcal of a protein source;
c. at least about 10 mg/100 kcal of lactoferrin, more preferably from about mg/100 kcal to about 220 mg/100 kcal of lactoferrin produced by a non-human source, most preferably about 90 mg/100 kcal to about 190 mg/100 kcal of lactoferrin produced by a non-human source; and d. about 0.1 g/100 kcal to about 1 g/100 kcal of a prebiotic composition comprising polydextrose and/or galactooligosaccharide. More preferably, the nutritional composition comprises about 0.3 g/100 kcal to about 0.7 g/100 kcal of a prebiotic composition which comprises a combination of polydextrose and galactooligosaccharide.

[0012] Preferably, the lactoferrin is non-human lactoferrin and/or human lactoferrin produced by a genetically modified organism. The term "organism", as used herein, refers to any contiguous living system, such as animal, plant, fungus or micro-organism. In one particularly preferred embodiment, the lactoferrin used is such that an effective amount of a nutritional composition containing lactoferrin may be administered to inhibit at least one of the invasive mechanisms of at least one pathogen in the gastrointestinal tract of a human, even if, during processing, the nutritional composition has been exposed to pH and temperature fluctuations typical of certain processing conditions like pasteurization. The lactoferrin includes anti-invasion mechanisms which may destruct the attachment factors and injection needle used by certain bacteria on human cells. In another particularly preferred embodiment, the lactoferrin used is such that an effective amount of a nutritional composition containing lactoferrin may be administered to inhibit the adhesion of at least one pathogen in the gastrointestinal tract of a human, even if, during processing, the nutritional composition has been exposed to pH and temperature fluctuations typical of certain processing conditions like pasteurization. Examples of such pathogens include Enterotoxigenic E. coli (ETEC), Enteropathogenic E. coli (EPEC), Haemophilus influenza, Shigatoxin producing E. coli (STEC), Enteroaggregative E. coli (EAEC), Salmonella ser.
Typhimurium, Shigella flexneri, Rotavirus, Norovirus, Respiratory syncytial virus (RSV), Adenovirus, and combinations thereof.
BEST MODE FOR CARRYING OUT THE INVENTION

[0013] The present disclosure provides novel nutritional products that are easily digested, provide physiochemical benefits, and/or provide physiological benefits. In an embodiment of the present disclosure, a nutritional composition comprises a lipid or fat, a protein source, a prebiotic composition having at least 20% of an oligosaccharide, especially one which comprises galacto-oligosaccharide (GOS), and lactoferrin which provides active anti-invasion or anti-adhesion mechanisms against strains of undesirable bacteria found in the human gastrointestinal tract. The lactoferrin included in the compositions is produced by a non-human source. In certain embodiments, the prebiotic comprises a combination of galacto-oligosaccharide and polydextrose. More particularly, the composition disclosed herein comprises:

a. up to about 7 g/100 kcal of a fat or lipid, more preferably about 3 to about 7 g/100 kcal of a fat or lipid;
b. up to about 5 g/100 kcal of a protein source, more preferably about 1 to about 5 g/100 kcal of a protein source;
c. d. about 0.1 g/100 kcal to about 1 g/100 kcal of a prebiotic composition comprising polydextrose and/or galactooligosaccharide. More preferably, the nutritional composition comprises about 0.3 g/100 kcal to about 0.7 g/100 kcal of a prebiotic composition which comprises a combination of polydextrose and galactooligosaccharide; and d. at least about 10 mg/100kCal of lactoferrin, more preferably about 70 mg to about 220 mg/100kCal of lactoferrin, most preferably about 90 mg to about 190 mg/100kCal of lactoferrin.
DEFINITIONS

[0014] As used herein, the term "prebiotic" means a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon that can improve the health of the host.

[0015] The term "probiotic" means a microorganism with low or no pathogenicity that exerts beneficial effects on the health of the host.

[0016] As used herein, the term "infant" is generally defined as a human from about birth to 12 months of age.

[0017] A "preterm infant" is an infant born after less than 37 weeks gestation.

[0018] A "full term infant" as used herein, means an infant born after at least 37 weeks gestation.

[0019] "Children" are defined as humans from the age of 12 months to about 12 years old.

[0020] An "anti-bacterially effective amount," as used herein is generally defined as an amount of lactoferrin that provides at least one anti-invasion mechanism against strains of bacteria.

[0021] "Lactoferrin produced by a non-human source" means lactoferrin which is produced by or obtained from a source other than human breast milk.
For example, lactoferrin for use in the present disclosure includes human lactoferrin produced by a genetically modified organism as well as non-human lactoferrin.

[0022] "Biologically active lactoferrin," means lactoferrin which possesses at least one anti-invasion or anti-adhesion mechanism against pathogens.

[0023] The term "non-human lactoferrin", as used herein, refers to lactoferrin having an amino acid sequence that is different from the amino acid sequence of human lactoferrin.

[0024] The term "organism", as used herein, refers to any contiguous living system, such as animal, plant, fungus or micro-organism.

[0025] The term "simulating," as used herein means having or taking the form or appearance of or having or producing a symptomatic resemblance to.
DISCLOSURE

[0026] In some embodiments, the nutritional product may be an infant formula. The term "infant formula" applies to a composition in liquid or powdered form that satisfies the nutrient requirements of an infant by being a substitute for human milk. In the United States, the content of an infant formula is dictated by the federal regulations set forth at 21 C.F.11. 100, 106 and 107. These regulations define macronutrient, vitamin, mineral, and other ingredient levels in an effort to simulate the nutritional and other properties of human breast milk. In a separate embodiment, the nutritional product may be a human milk fortifier, meaning it is a composition which is added to human milk in order to enhance the nutritional value of human milk. As a human milk fortifier, the disclosed composition may be in powder or liquid form. In yet another embodiment, the disclosed nutritional product may be a children's nutritional composition.

[0027] The nutritional products of the disclosure may provide minimal, partial, or total nutritional support. The compositions may be nutritional supplements or meal replacements. In some embodiments, the compositions may be administered in conjunction with a food or nutritional composition. In this embodiment, the compositions can either be intermixed with the food or other nutritional compositions prior to ingestion by the subject or can be administered to the subject either before or after ingestion of a food or nutritional composition. The compositions may be administered to preterm infants receiving infant formula, breast milk, a human milk fortifier, or combinations thereof.

[0028] The compositions may, but need not, be nutritionally complete. The skilled artisan will recognize "nutritionally complete" to vary depending on a number of factors including, but not limited to, age, clinical condition, and dietary intake of the subject to whom the term is being applied. In general, "nutritionally complete" means that the nutritional composition of the present disclosure provides adequate amounts of all carbohydrates, lipids, essential fatty acids, proteins, essential amino acids, conditionally essential amino acids, vitamins, minerals, and energy required for normal growth. As applied to nutrients, the term "essential"
refers to any nutrient which cannot be synthesized by the body in amounts sufficient for normal growth and to maintain health and which therefore must be supplied by the diet. The term "conditionally essential" as applied to nutrients means that the nutrient must be supplied by the diet under conditions when adequate amounts of the precursor compound is unavailable to the body for endogenous synthesis to occur.

[0029] The composition which is "nutritionally complete" for the preterm infant will, by definition, provide qualitatively and quantitatively adequate amounts of all carbohydrates, lipids, essential fatty acids, proteins, essential amino acids, conditionally essential amino acids, vitamins, minerals, and energy required for growth of the preterm infant. The composition which is "nutritionally complete"
for the term infant will, by definition, provide qualitatively and quantitatively adequate amounts of all carbohydrates, lipids, essential fatty acids, proteins, essential amino acids, conditionally essential amino acids, vitamins, minerals, and energy required for growth of the term infant. The composition which is "nutritionally complete" for a child will, by definition, provide qualitatively and quantitatively adequate amounts of all carbohydrates, lipids, essential fatty acids, proteins, essential amino acids, conditionally essential amino acids, vitamins, minerals, and energy required for growth of a child.

[0030] The nutritional composition may be provided in any form known in the art, including a powder, a gel, a suspension, a paste, a solid, a liquid, a liquid concentrate, or a ready-to-use product. In one preferred embodiment, the nutritional composition is an infant formula, especially an infant formula adapted for use as sole source nutrition for an infant.

[0031] In the preferred embodiments, the nutritional product disclosed herein may be administered enterally. As used herein, "enteral" means through or within the gastrointestinal, or digestive, tract, and "enteral administration"
includes oral feeding, intragastric feeding, transpyloric administration, or any other introduction into the digestive tract.

[0032] Lactoferrins are single chain polypeptides of about 80 kD containing ¨ 4 glycans, depending on the species. The 3-D structures of lactoferrin of different species are very similar, but not identical. Each lactoferrin comprises two homologous lobes, called the N- and C-lobes, referring to the N-terminal and C-terminal part of the molecule, respectively. Each lobe further consists of two sub-lobes or domains, which form a cleft where the ferric ion (Fe3+) is tightly bound in synergistic cooperation with a (bi)carbonate anion. These domains are called Ni, N2, Cl and C2, respectively. The N-terminus of lactoferrin has strong cationic peptide regions that are responsible for a number of important binding characteristics. Lactoferrin has a very high isoelectric point (¨pI 9) and its cationic nature plays a major role in its ability to defend against bacterial, viral, and fungal pathogens. There are several clusters of cationic amino acids residues within the N-terminal region of lactoferrin mediating the biological activities of lactoferrin against a wide range of microorganisms. For instance, the N-terminal residues 47 of human lactoferrin (1-48 of bovine lactoferrin) are critical to the iron-independent biological activities of lactoferrin. In human lactoferrin, residues 2 to (RRRR) and 28 to 31 (RKVR) are arginine-rich cationic domains in the N-terminus especially critical to the antimicrobial activities of lactoferrin. A
similar region in the N-terminus is found in bovine lactoferrin (residues 17 to 42;
FKCRRWQWRMKKLGAPSITCVRRAFA).

[0033] As described in "Perspectives on Interactions Between Lactoferrin and Bacteria" which appeared in the publication BIOCHEMISTRY AND CELL BIOLOGY, pp 275-281 (2006), lactoferrins from different host species may vary in their amino acid sequences though commonly possess a relatively high isoelectric point with positively charged amino acids at the end terminal region of the internal lobe.
Suitable lactoferrins for use in the present disclosure include those having at least 48% homology with the amino acid sequence AVGEQELRKCNQWSGL at the HLf (349-364) fragment. In some embodiments, the lactoferrin has at least 65%

homology with the amino acid sequence AVGEQELRKCNQWSGL at the HLf (349-364) fragment, and, in embodiments, at least 75% homology. For example, non-human lactoferrins for use in the present disclosure include, without limitation, bovine lactoferrin, porcine lactoferrin, equine lactoferrin, buffalo lactoferrin, goat lactoferrin, murine lactoferrin and camel lactoferrin.

[0034] Surprisingly, the forms of lactoferrin included herein maintain relevant activity even if exposed to a low pH (i.e., below 7, and even as low as about 4.6 or lower) and/or high temperatures (i.e., above about 65 C, and as high as about 120 C, conditions which would be expected to destroy or severely limit the stability or activity of human lactoferrin or recombinant human lactoferrin. These low pH
and/or high temperature conditions can be expected during certain processing regimen for nutritional compositions of the types described herein, such as pasteurization. For instance, while bovine lactoferrin has an the amino acid composition which has only about a 70% sequence homology to that of human lactoferrin, and is stable and remains active under conditions under which human or recombinant human lactoferrin become unstable or inactive, bovine lactoferrin has bactericidal activity against undesirable bacterial pathogens found in the human gut.

[0035] In U.S. Patent No. 4,791,193, Okonogi et al. discloses a process for producing bovine lactoferrin in high purity. Generally, the process as disclosed includes three steps. Raw milk material is first contacted with a weakly acidic cationic exchanger to absorb lactoferrin followed by the second step where washing takes place to remove nonabsorbed substances. A desorbing step follows where lactoferrin is removed to produce purified bovine lactoferrin. Other methods may include steps as described in U.S.
Patent Nos. 7,368,141, 5,849,885, 5,919,913 and 5,861,491.

[0036] In one embodiment, lactoferrin is present in the nutritional composition in an amount of at least about 10 mg/100 kCal, especially when the nutritional composition is intended for use by children. In certain embodiments, the upper limit of lactoferrin is about 240 mg/100 kCal. In another embodiment, where the nutritional composition is an infant formula, lactoferrin is present in the nutritional composition in an amount of from about 70 mg to about 220 mg/100 kCal; in yet another embodiment, lactoferrin is present in an amount of about mg to about 190 mg/100 kCal. Nutritional compositions for infants can include lactoferrin in the quantities of from about 0.5 mg to about 1.5 mg per milliliter of formula. In nutritional compositions replacing human milk, lactoferrin may be present in quantities of from about 0.6 mg to about 1.3 mg per milliliter of formula.

[0037] Suitable fat or lipid sources for practicing the present disclosure may be any known or used in the art, including but not limited to, animal sources, e.g., milk fat, butter, butter fat, egg yolk lipid; marine sources, such as fish oils, marine oils, single cell oils; vegetable and plant oils, such as corn oil, canola oil, sunflower oil, soybean oil, palmolein, coconut oil, high oleic sunflower oil, evening primrose oil, rapeseed oil, olive oil, flaxseed (linseed) oil, cottonseed oil, high oleic safflower oil, palm stearin, palm kernel oil, wheat germ oil; medium chain triglyceride oils and emulsions and esters of fatty acids; and any combinations thereof.

[0038] Bovine milk protein sources useful in practicing the present disclosure include, but are not limited to, milk protein powders, milk protein concentrates, milk protein isolates, nonfat milk solids, nonfat milk, nonfat dry milk, whey protein, whey protein isolates, whey protein concentrates, sweet whey, acid whey, casein, acid casein, caseinate (e.g. sodium caseinate, sodium calcium caseinate, calcium caseinate) and any combinations thereof.

[0039] In one embodiment, the proteins are provided as intact proteins. In other embodiments, the proteins are provided as a combination of both intact proteins and partially hydrolyzed proteins, with a degree of hydrolysis of between about 4% and 10%. In yet another embodiment, the protein source may be supplemented with glutamine- containing peptides.

[0040] In a particular embodiment of the disclosure, the whey:casein ratio of the protein source is similar to that found in human breast milk. In an embodiment, the protein source comprises from about 20% to about 85% whey protein. In another embodiment, the protein source may comprise from about 20%

to about 80% casein. In yet another embodiment of the disclosure, the protein source includes about 60% to about 85% whey and about 15% to about 40% casein.

[0041] In one embodiment of the disclosure, the nutritional composition may also contain one or more probiotics. Any probiotic known in the art may be acceptable in this embodiment provided it achieves the intended result. In a particular embodiment, the probiotic may be selected from Lactobacillus species, Lactobacillus rharnnosus GG, Bifidobacterium species, Bifidobacteriurn longum, Bifidobacterium breuis and Bifidobacterium animalis subsp. lactis BB-12.

[0042] If included in the composition, the amount of the probiotic may vary from about 104 to about 1049 colony forming units (du) per kg body weight per day.
In another embodiment, the amount of the probiotic may vary from about 106 to about 109 cfu per kg body weight per day. In yet another embodiment, the amount of the probiotic may be at least about 106cfu per kg body weight per day.
Moreover, the disclosed composition may also include probiotic-conditioned media components.

[0043] In an embodiment, the probiotic(s) may be viable or non-viable.
As used herein, the term "viable", refers to live microorganisms. The term "non-viable" or "non-viable probiotic" means non-living probiotic microorganisms, their cellular components and metabolites thereof. Such non-viable probiotics may have been heat-killed or otherwise inactivated but retain the ability to favorably influence the health of the host. The probiotics useful in the present disclosure may be naturally-occurring, synthetic or developed through the genetic manipulation of organisms, whether such new source is now known or later developed.
[00441 The nutritional composition contains one or more prebiotics. Such prebiotics may be naturally-occurring, synthetic, or developed through the genetic manipulation of organisms and/or plants, whether such new source is now known or developed later. In certain embodiments, the prebiotic included in the compositions of the present disclosure include those taught by U.S. Patent No.

7,572,474.
[00451 Prebiotics useful in the present disclosure may include oligosaccharides, polysaccharides, and other prebiotics that contain fructose, xy]ose, soya, galactose, glucose and mannose. More specifically, prebiotics useful in the present disclosure may include lactulose, lactosucrose, raffinose, gluco-oligosaccharide, inulin, polydextrose, polydextrose powder, galacto-oligosaccharide, fructo-oligosaccharide, isomalto-oligosaccharide, soybean oligosaccharides, lactosucrose, xylo-oligosacchairde, chito-oligosaccharide, manno-oligosaccharide, aribino-oligosaccharide, siallyl-oligosaccharide, fuco-oligosaccharide, and gentio-oligosaccharides.
[0046] In an embodiment, the total amount of prebiotics present in the nutritional composition may be from about 1.0 g/L to about 10.0 g/L of the composition. Alternatively, the total amount of prebiotics present in the nutritional composition may be from about 2.0 g/L and about 8.0 g/L of the composition. At least 20% of the prebiotics should comprise galacto-oligosaccharide (GOS), polydextrose, or a mixture thereof. Preferably, the nutritional compositions comprise polydextrose and galactooligosaccaharide. Optionally, in addition to polydextrose and/or galactooligosaccaharide, the nutritional compositions comprise one or more additional prebiotics. The amount of each of galacto-oligosaccharide and/or polydextrose in the nutritional composition may, in an embodiment, be within the range of from about 1.0 g/L to about 4.0 g/L.
[0047] In an embodiment, the total amount of prebiotics present in the nutritional composition may be from about 0.1 g/100 kcal to about 1 g/100 kcal.
More preferably, the total amount of prebiotics present in the nutritional composition may be from about 0.3 g/100 kcal to about 0.7 g/100 kcal. At least 20%
of the prebiotics should comprise galactooligosaccharide (GOS) and/or polydextrose (PDX).
[0048] The amount of galacto-oligosaccharide in the nutritional composition may, in an embodiment, be from about 0.2 g/100 Kcal to about 1.0 g/100 Kcal.
In another embodiment, the amount of galacto-oligosaccharide in the nutritional composition may be from about 0.1 g/100 Kcal to about 0.5 g/100 Kcal. In yet another embodiment, the amount of galactooligsaccharide is within the range of from about 0.2 g/100 kcal to about 0.6 g/100 kcal. If polydextrose is used as a prebiotic, the amount of polydextrose in the nutritional composition may, in an embodiment, be within the range of from about 0.1 g/100 kcal to about 1 g/100 kcal.
In another embodiment, the amount of polydextrose is within the range of from about 0.2 g/100 kcal to about 0.6 g/100 kcal. In yet another embodiment, if polydextrose is used in the prebiotic composition, the amount of polydextrose in the nutritional composition may, in an embodiment, be within the range of from about 0.1 g/100 Kcal to about 0.5 g/100 Kcal. In certain embodiments, the ratio of polydextrose to galactooligosaccharide in the prebiotic composition is between about 9:1 and about 1:9.

[0049] Preferably, the prebiotic composition, in combination with lactoferrin, inhibits the adhesion of one or more pathogens in the gastrointestinal tract when the nutritional compositions are provided to humans. An example of one such pathogen is Enterobacter sakazakii (otherwise known as Cronobacter sakazakii).

Another pathogen for which adhesion is inhibited by the combination of lactoferrin with the prebiotic composition is E. coll.
[0050] The nutritional formulation of the disclosure may also contain a source of long chain polyunsaturated fatty acids (LCPUFAs) which comprise docosahexanoic acid (DHA). Other suitable LCPUFAs include, but are not limited to, a-linoleic acid, y-linoleic acid, linoleic acid, linolenic acid, eicosapentanoic acid (EPA) and arachidonic acid (ARA).
[0051] In one embodiment, the nutritional composition is supplemented with both DHA and ARA. In this embodiment, the weight ratio of ARA:DHA may be from about 1:3 to about 9:1. In one embodiment of the present disclosure, this ratio is from about 1:2 to about 4:1.
[0052] The amount of long chain polyunsaturated fatty acids in the nutritional composition may vary from about 5 mg/100 kcal to about 100 mg/100 kcal, more preferably from about 10 mg/100 kcal to about 50 mg/100 kcal.
[0053] The nutritional composition may be supplemented with oils containing DHA and ARA using standard techniques known in the art. For example, DHA
and ARA may be added to the formula by replacing an equivalent amount of an oil, such as high oleic sunflower oil, normally present in the formula. As another example, the oils containing DHA and ARA may be added to the formula by replacing an equivalent amount of the rest of the overall fat blend normally present in the formula without DHA and ARA.
[0054] If utilized, the source of DHA and ARA may be any source known in the art such as marine oil, fish oil, single cell oil, egg yolk lipid, and brain lipid. In some embodiments, the DHA and ARA are sourced from the single cell Martek oil, DHASCO and ARAS CO respectively, or variations thereof. The DHA and ARA
can be in natural form, provided that the remainder of the LCPUFA source does not result in any substantial deleterious effect on the infant. Alternatively, the DHA and ARA can be used in refined form.
[0055] In an embodiment of the present disclosure, sources of DHA and ARA

are single cell oils as taught in U.S. Pat. Nos. 5,374,567; 5,550.156; and 5,397,591.
However, the present disclosure is not limited to only such oils.
[0056] In certain embodiments, the nutritional compositions comprise from about 0.5 mg/100 kcal to about 5 mg/100 kcal of iron, including iron bound to lactoferrin.
[0057] A benefit of lactoferrin as used in embodiments of the present disclosure is its anti-invasion and anti-adhesion mechanism in the human gastrointestinal tract. Specifically, lactoferrin may destroy the injection needle used by certain bacteria to invade and cause pathogenesis. Likewise, lactoferrin inhibits the adhesion of pathogens in the gastrointestinal tract of humans.
One such example of a bacterium known to cause pathogenesis is Escherichia coli which may cause diarrhea in infants, children and adults and is realized as an agent for pediatric diarrhea. The K coli produces and translocates bacterial protein through a needle complex via a type III secretory system.
[0058] The secretory system of many gram-negative pathogenic bacteria is a type III secretion including the following bacteria: Shigella, Salmonella, Pseudotnonas, and Escherichia coli. The type III secretory system functions through use of a needle for the transport of virulent proteins from the bacterial cytoplasm through the needle directly into the host cell's cytoplasm. The use of the needle provides for a passage through the multiple membranes including the double membranes of the gram-negative bacterium and the eukaryotic membrane of the human cell. Specifically, in strains of E. coli the needle complex is comprised of E. coli secretion component F (EscF) with E. coli secreted protein A (EspA) attaching to the tip of the needle, forming a generally hollow structure for the passage of components from the bacteria to the host human cell. At this point, bacterial proteins such as EspB may be introduced into the host cell through this tube. While the physiology of EspB may not be fully understood in the article "The Enteropathogenic E. coli effector EspB facilitates micro villas effacing and Ant iphagocytosis by Inhibiting Myosin Function" in CELL HOSTS AND MICROBE, pp 383-392 (2007), EspB is described as binding to myosins which ultimately suppresses phagocytosis as a human immune response. Generally, myosin proteins interact with actin filaments to participate in cellular processes such as phagocytosis in eliminating potential bacterial pathogens. Harmful symptoms occur where EspB emitted by the E. coli inhibits the interaction between various myosin proteins and actin filaments in suppressing phagocytosis, leading to diarrhea or other gastric distress in infants, children and adults.
[0059] One of the anti-invasion mechanisms of lactoferrin is in inhibiting the translocation of EspB into human cells. Specifically, one mechanism may include the inhibition of the formation of the necessary secretory structures for translocating EspB from the bacteria. Lactoferrin is capable of degrading EspA, the protein responsible for the tube like structure for translocating Esp B
into the host cell. As EspA may be degraded by lactoferrin, the portal through the human cell membrane would not be created thus alleviating pathogenesis created from Esp B entering into the human cell's cytoplasm. Furthermore, lactoferrin may also possess proteolytic activity resulting in the degrading EspB. Ultimately, lactoferrin effectively disrupts the needle complex associated with the pathogen's secretion system while simultaneously degrading proteins responsible for symptoms including gastrointestinal distress and diarrhea.
EXAMPLES
[0060] The following examples are provided to illustrate embodiments of the nutritional composition of the present disclosure but should not be interpreted as any limitation thereon. Other embodiments within the scope of the claims herein will be apparent to one skilled in the art from the consideration of the specification or practice of the nutritional composition or methods disclosed herein. It is intended that the specification, together with the example, be considered to be exemplary only, with the scope and spirit of the disclosure being indicated by the claims which follow the examples.

[0061] This Example exemplifies the inhibition of pathogens, namely E.
sakazakii 4603 and 29004 and E. coli E2348/69, by lactoferrin alone and in combination with polydextrose and galactooligosaccharide.
[0062] Based on a preliminary experiment, it is determined that cultures of E. sakazakii 4603 and 29004 give the highest adherence rates to HEp-2 cells.
After 6 hour incubation, cultures of these E. sakazakii strains as well as cultures of E. coli E2348/69 are harvested by centrifugation, washed with phosphate buffered saline, and re-suspended in minimal essential medium (MEM) supplemented with 10% fetal bovine serum. HEp-2 cells (obtained from the ATTC) are grown in 75 cm2 tissue culture flasks containing 25 ml of MEM supplemented with 10% FBS in a CO2 incubator at tissue culture conditions. Confluent HEp-2 cells are harvested by adding 0.5 ml of 0.25% Trypsin-EDTA Solution (Sigma) and incubating for 15 minutes at tissue culture conditions. Tryp sin is inactivated with 0.5 ml of FBS, and the cells are seeded onto 12-mm diameter glass coverslips in 24-well tissue culture plates at approximately 3.6 x 105 viable cells per well. Plates are incubated under tissue culture conditions for two days prior to the start of each experiment, or until confluency is reached.
[0063] Immediately before the start of the assay, lactoferrin at final concentrations of 0.1 mg/ml, 0.6 mg/ml, and 1 mg/ml, alone and in combination with a 1:1 blend of galactooligosaccharide (obtained from DOMO) and polydextrose (obtained from DMV) at final concentrations of 4 mg/ml and 16 mg/ml of, is added to the HEp-2 cells. Control wells containing no lactoferrin are also prepared.

Then, 900:1 of the E. coli or E. sakazakii culture (containing ca. 107 cells) are added to each well (in triplicate). Tissue culture plates are then incubated at 37 C
in a CO2 incubator for three hours. The wells are then washed five times to remove non-adherent cells, and adhered bacteria are enumerated by microscopic enumeration and quantitative real-time PCR.
[0064] For microscopic enumeration, coverslips are fixed with 100%
methanol, stained with 10% Geimsa for 15 minutes, washed with distilled water, and dried overnight. The coverslips are mounted on microscope slides and observed under a phase contrast microscope with the 100x objective. Fifteen photomicrographs of each coverslip are taken using Motic Image software following an established geometric pattern throughout the entire coverslip. The number of cells and bacteria in each image is counted using Image J image analysis software.
Adherence is calculated as the number of adhered bacteria per HEp-2 cell.
Adherence inhibition is calculated as the number of adhered bacteria per cell in the control minus the number of adhered bacteria per cell in the treatment divided by the number of adhered bacteria per cell in the control. For experiments using cultures of E. coli, cells with E. coli microcolonies are manually counted.
Cells with four or more bacteria are considered positive for having a typical localized adherence phenotype. The number of HEp-2 cells with adhered microcolonies is determined and adherence and adherence inhibition is calculated as described above. Experiments are performed in triplicate and replicated three times (n =
9).
[0065] In addition to the microscopic enumeration, adhered cells are also enumerated by quantitative real-time PCR (qRT-PCR), as described in Humphries et al., Interactions of enteropathogenic Escherichia coli with pediatric and adult intestinal biopsy specimens during early adherence, Infect. Immun., 77, 4463-(2009). Briefly, genomic DNA are extracted from the infected HEp-2 cells and quantified by qRT-PCR using oligonucleotide primers that amplify the 16s rRNA
region of E sakazakii 4603 and 29004 or E. coli 2348/69. Appropriately diluted whole genomic DNA is used as internal controls and to prepare standard curves relating qPCR endpoints to cell concentrations. The PCR mixture consists of 11.250 SYBR solution, 2.5 MasterMix, 1 pl of each primer, and 5 pd of DNA
template. The PCR reactions are performed using an Eppendorf Mastercycler Realplex2.

[0066] This example illustrates an embodiment of a nutritional product according to the present disclosure.
Description kg per 100 kg carbohydrate, total 38.9 protein, total 28.8 fat, total 25.6 prebiotics 4.5 soy lecithin 0.8 lactoferrin 0.3 calcium carbonate 0.5 potassium citrate 0.2 ferrous sulfate 0.05 potassium chloride 0.048 magnesium oxide 0.023 sodium chloride 0.025 zinc sulfate 0.015 cupric sulfate 0.002 manganese sulfate 0.0003 sodium selenite 0.00003 choline chloride 0.144 ascorbic acid 0.093 Niacinamide 0.006 calcium pantothenate 0.003 vitamin A palmitate 0.007 vitamin B12 0.002 vitamin D3 0.000001 Riboflavin 0.0008 thiamin 0.0006 vitamin B6 0.0004 folic acid 0.0001 vitamin K1 0.006 biotin 0.00002 inositol 0.03 vitamin E acetate 0.01 taurine 0.05 L-carnitine 0.001 10067] This example illustrates another embodiment of a nutritional product according to the present disclosure.
Description kg per 100 kg carbohydrate, total 24.7 protein, total 31.9 fat, total 39.3 prebiotics 3.6 lactoferrin 0.1 calcium carbonate 0.15 ferrous sulfate 0.03 zinc sulfate 0.01 copper sulfate 0.00025 manganese sulfate 0.0002 sodium selenite 0.00001 choline bitartrate 0.05 ascorbic acid 0.004 sodium ascorbate 0.04 niacinamide 0.007 calcium pantothenate 0.0005 vitamin A palmitate 0.0005 vitamin D3 0.0002 riboflavin 0.0001 thiamin 0.00005 vitamin B6 0.00005 folic acid 0.000067 vitamin K1 0.00002 vitamin E acetate 0.008 taurine 0.02 fish oil 0.2 B-glucan 0.03 10068] This example illustrates one embodiment of ingredients that can be used to prepare the nutritional product according to the present disclosure.
water 872 ml lactose 65.6 mg vegetable oil blend 353.0 mg nonfat milk evaporated 34.0 mg whey protein concentrate 8.5 mg galacto-oligosaccharide 4.7 mg casein 3.5 mg polydextrose 2.4 mg lactoferrin solution (10%) 1.0 mg single cell DHA and ARA oil blend 0.94 mg mono- and di-glycerides 0.7 mg calcium carbonate 0.44 mg calcium phosphate 0.4 mg potassium citrate 0.4 mg potassium chloride 0.4 mg soy lecithin 0.4 mg sodium chloride 0.3 mg potassium phosphate 0.3 mg choline chloride 0.2 mg magnesium oxide 0.08 mg calcium hydroxide 0.08 mg ferrous suflate 0.07 mg 10069] This example illustrates another embodiment of ingredients that can be used to prepare the nutritional product according to the present disclosure.
water 686 ml reduced minerals whey 215 mg nonfat milk evaporated 67 mg vegetable oil blend 33 mg lactose 17 mg galacto-oligosaccharide 4.7 mg polydextrose 2.4 mg lactoferrin solution (10%) 1.0 mg single cell DHA and ARA oil blend 0.9 mg mono- and di-glycerides 0.7 mg calcium carbonate 0.44 mg calcium phosphate 0.4 mg potassium citrate 0.4 mg potassium chloride 0.4 mg soy lecithin 0.4 mg potassium phosphate 0.3 mg carrageenan 0.3 mg sodium citrate 0.2 mg choline chloride 0.2 mg magnesium oxide 0.08 mg calcium chloride 0.08 mg ferrous suflate 0.07 mg [0070] The discussion of the references cited herein is intended merely to summarize the assertions made by their authors and no admission is made that any reference constitutes prior art. Applicants reserve the right to challenge the accuracy and pertinence of the cited references.
[0071] Although preferred embodiments of the disclosure have been described using specific terms, devices, and methods, such description is for illustrative purposes only. The words used are words of description rather than of limitation.
It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of the present disclosure, which is set forth in the following claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. For example, while methods for the production of a commercially sterile liquid nutritional supplement made according to those methods have been exemplified, other uses are contemplated. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained therein.

Claims (5)

What is claimed is:

1. Use of a nutritional composition comprising:
a) a fat or lipid source;
b) a protein source;
c) lactoferrin produced by a non-human source, wherein the lactoferrin is present at a level of about 70 mg/100 kcal to about 220 mg/100 kcal; and d) a prebiotic composition comprising galactooligosaccharide and polydextrose;
for inhibiting the adhesion Enterobacter sakazakii of at least one pathogen in the gastrointestinal tract of a human.

2. The use of claim 1, wherein the nutritional composition further comprises about 5 to about 100 mg/100 kcal of a source of long chain polyunsaturated fatty acids which comprises docosahexaenoic acid.

3. The use of claim 2, wherein the source of long chain polyunsaturated fatty acids further comprises arachidonic acid.

4. The use according to claim 1, wherein the fat or lipid source is present at a level of about 3 g/100 kcal to about 7 g/100 kcal.

5. The use according to claim 1, wherein protein source is present at a level of about 1 g/100 kcal to about 5 g/100 kcal.