WO2005020699A1

WO2005020699A1 - Tea for gut health

Info

Publication number: WO2005020699A1
Application number: PCT/EP2004/008897
Authority: WO
Inventors: Johannes Matheus Maria Van Amelsvoort; Maaike Johanna Bruins; Bernardus Jan-Willem Van Klinken; Joerg Erwin Ueckert
Original assignee: Unilever N.V.; Unilever Plc; Hindustan Lever Limited
Priority date: 2003-08-29
Filing date: 2004-08-06
Publication date: 2005-03-10

Abstract

The present inventions provides the use of tea leaves, tea extract or mixture thereof in the manufacture of an edible composition for use in a method of preventing or treating infectious diarrhoea, and wherein said method comprises ingesting the edible composition in an amount such that the subject consumes a daily dosage of; - greater than 50 mg/kg of body weight of tea extract, or - greater than 150 mg/kg of body weight of tea leaves, or - greater than 100 mg/kg of body weight of mixture of tea leaves and tea extract.

Description

TEA FOR GUT HEALTH

FIELD OF THE INVENTION

The present invention relates to the use of black or green tea, and extracts thereof, to aid in the treatment or prevention of infectious diarrhoea.

BACKROUND OF THE INVENTION

Travelers' diarrhoea is a common problem for those travelling overseas. Current estimates are that 60 million travelers from the West visit high risk areas annually, and of these about 30- 50% suffer bouts of diarrhoea. Furthermore, diarrhoeal diseases pose a heavy burden on developing countries, accounting for 1.5 billion bouts of illness a year, and are the second largest infectious killer among children under five years of age. Today, diarrhoeal diseases claim nearly two million lives a year among children under five years of age (WHO, 1999) . There are two types of diarrhoea, infectious and non-infectious .

Some of the pathogens most strongly associated with diarrhoea are rotavirus, Shigella spp. and enterotoxigenic Escherichia coli (ETEC) . Although problems occur mostly in children, travelers to areas of the world with poor hygiene are also at risk. Even those travelling within northern Europe, North America, or Australia are at increased risk (4-8% chance) . The most important pathogens causing travelers ^■ diarrhoea are ETEC and other E. coli types and Shigella. Tea may modulate the microflora inhibiting the growth of pathogens and may limit pathogen-induced fluid losses involved in diarrhoea.

Several suggestions have been made to use green tea to improve intestinal microflora balance in animals. N.Ishihara et al in Livestock Production Science, 68 (2001) pages 217-219 disclose that green tea extracts were added to the feed of calves and showed moderate and wide-spectrum inhibitory effects on the growth of pathogenic bacteria which overall lead to an improvement in the microflora balance in the calves guts' and a decrease in the frequency of non-infectious diarrhoea.

It is also known to treat tea leaves for inclusion in food products. EP-A-0 951 839 discloses treating fresh green tea leaves with a solution of water and a crystalline trehalose to obtain a treated tea leaf. The treated tea leaf may be incorporated into foods and avoids the need for frying food and thus increasing the fat content thereof. US 6,207,214 discloses a process of making traditional Korean snacks comprising 80-95 %wt glutinous rice. The snacks may comprise 5 to 20 %wt of powdered green tea and they are steamed to produce the snack food. JP 03168046 (Nippon Kayaku Co Ltd) discloses the use of a tea extract as a food raw material by compounding the tea extract with a cyclodextrin and/or a peptide. JP 02265446 (House Food Ind Co Ltd) discloses the use of a black tea extract used to make a black tea jelly. US 4,839,187 discloses a composition comprising a food susceptible to lipid oxidation and a black tea extract containing 0.005% to 1.5% tea solids based on the weight of the food, wherein the tea extract has been obtained by aqueous extraction of the black tea at a temperature of from 130 to 210 °C. None of these documents are concerned with health effects in the consumers of the food product .

It is also known in south east Asian cooking to include tea leaves in raw foods such as salads. JP 06/056, 689-A discloses food compositions for the prevention and treatment of infectious diarrhoea. The compositions comprise a chitin which contains a tea extract either adsorbed or chemically bonded therewith. When the tea is not bound with chitin, the compositions are said to have an unacceptable, bitter, taste.

Bruneton in "Pharmacognosy", 2^nd edition, chapterδ, 1999, Intercept Ltd, Paris, France, discloses that the tea leaf can be used orally, traditionally for the symptomatic treatment of mild diarrhoea.

Besra at al in "Antidiarrhoeal activity of hot water extract of black tea (camellia sinensis)", Phytotherapy Research, April 2003, pages 380-384, discloses that black tea extract was found to possess antidiarrhoeal activity in a rodent model of castor oil-induced diarrhoea.

Toda et al in "The protective activity of tea against infection by Vibrio cholerae 01", Journal of Applied Bacteriology, 70 (2), 109-112, discloses that black tea extract reduced fluid accumulation induced by cholera toxin in sealed intestines of mice and by cholera in ligated intestinal loops of rabbits.

However, despite the above, there is still a need in the art for effective methods of treating or preventing infectious diarrhoea. In particular, there is a need for such methods which do not rely upon pharmaceuticals and/or synthetic ingredients .

Furthermore, there is also a need for such compositions which are effective and economical and relatively simple to produce. There is also a need for such compositions that fulfil one or more of the following criteria: they can be stored without refrigeration and have good keeping characteristics. - they can be consumed as a part of the typical daily diet for all people, they do not require any further special preparation, they can be added to other food products, they can be made from readily available and economical ingredients, the ingredients that they are prepared from do not need to be pre-prepared with other materials.

The present invention seeks to address one or more of the above-mentioned problems.

SUMMARY OF THE INVENTION We have surprisingly found that when tea, a tea extract or a mixture thereof, is consumed at a given dosage beneficial effects upon the treatment or prevention of infectious diarrhoea are obtained. This is especially true when the compositions are taken as a part of the daily diet.

The present invention therefore provides the use of tea leaves, tea extract or mixture thereof in the manufacture of an edible composition for use in a method of preventing or treating infectious diarrhoea and wherein said method comprises ingesting the edible composition in an amount such that the subject consumes a daily dosage of; - greater than 50 mg/kg of body weight of tea extract, or greater than 150mg/kg of body weight of tea leaves, or greater than 100 mg/kg of body weight of a mixture of tea leaves and tea extract,

The term "use of tea" and "tea" as used herein refers to the tea leaves, or, to pieces of tea leaves, as the context requires. The term "tea leaves" as used herein includes pieces of tea leaves and not just the whole tea leaf.

The amount of tea extract refers to the dry weight of the tea extract .

The edible compositions of the invention can be used by anyone to treat or prevent infectious diarrhoea. The edible compositions can take many forms and are suitable for inclusion as a part of the daily diet to simply replace the non-tea containing equivalent. This means that they are readily accepted into a daily diet by adults and children alike. Furthermore they can be formulated so that they can be stored without refrigeration and have good keeping characteristics, which is particularly important in developing countries where refrigerated storage facilities are often not available and/or the climate is warm.

Furthermore, the edible compositions can generally be prepared from readily available and economical ingredients (as long as a supply of tea leaf or tea extract is available) . Also, the tea can be used in its conventional state of either the leaf or as an extract and does not require pre-processing with other ingredients before it can be added to the ingredients of the composition.

Without wishing to be bound by theory, it is believed that the polyphenols in the black and green tea leaves and tea extracts are able to inhibit the growth of both Gram-negative and Gram- positive pathogenic bacteria and viruses, which are major causative agents of intestinal infection leading to diarrhoea. This is achieved without adversely affecting beneficial gut bacteria, such as lactobacilli and bifido bacteria, even at very high concentrations of the bacteria. Furthermore, it is believed that black and green tea leaves and tea extracts are able to limit pathogen- and enterotoxin-induced intestinal fluid losses in diarrhoea.

Again, without wising to be bound by theory, it is believed that the tea may provide the effects referred to above by one or more of the following possible modes of action:

• complexation of iron, which is an essential micronutrient required for bacterial growth.

• disturbance of the membrane potential which leads to cessation of metabolic functions of the bacteria

• interaction with membrane proteins and block energy (glucose) transport into cells of the bacteria • causing membrane damage and subsequent leakage of cell constituents into the environment

• inhibition of enterotoxin secretion from pathogens

• neutralisation of enterotoxin

• inhibition of pathogen- and enterotoxin-induced chloride and water transport to the gut lumen. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about." All amounts in the food product are by weight, based on the weight of the food product unless otherwise specified.

The term "comprising" is meant not to be limiting to any subsequently stated elements but rather to encompass non- specified elements of major or minor functional importance. In other words the listed steps, elements or options need not be exhaustive. Whenever the words "including" or "having" are used, these terms are meant to be equivalent to "comprising" as defined above.

DETAILED DESCRIPTION OF THE INVENTION

The invention will now be discussed in greater detail .

The tea or tea extract

According to the present invention, the edible composition is consumed by a subject in an amount such that the subject consumes a daily dosage of;

- greater than 50 mg/kg of body weight of tea extract, or - greater than 150 mg/kg of body weight of tea leaves, or

- greater than 100 mg/kg of body weight of a mixture of tea leaves and tea^' extract. The edible composition is preferably consumed by a subject in an amount such that the subject consumes a daily dosage of up to 1000 mg/kg of body weight of tea extract, more preferably 55 to 500 mg/kg, such as 60 to 200 mg/kg. Alternatively the subject preferably consumes a daily dosage of up to 3000 mg/kg of body weight of tea leaves, more preferably 165 to 1500 mg/kg, such as 180 to 600 mg/kg. When a mixture of tea leaves and tea extract is used the subject preferably consumes a daily dosage of up to 2000 mg/kg of body weight of the mixture, more preferably 150 to 1500 mg/kg, such as 200 to 1000 mg/kg.

The dosage required will depend upon the individual according to their needs. The subject may be a human or animal but is preferably a human.

The tea or tea extract may be used in any suitable form according to the invention in an edible composition. A mixture of tea and a tea extract may also be used.

Preferably the tea is used in an unbound state. As used herein

"unbound state " means that the tea is used (either as the leaf or as an extract of the tea, or as the mixture thereof) in a state in which it is not adsorbed or chemically bound to another material .

Both green tea and black tea, and their extracts may be used according to the present invention. Any black or green tea, or extract thereof may be used according to the invention. The term black tea as used herein also includes semi-fermented tea such as oolong. Where the tea leaf is used, it may be used in a dried or non- dried form. It may be as the whole leaf, as pieces of the leaf, or as particles produced from the leaf.

The tea extract may be produced by any conventional method such as making an extract of the tea with hot or boiling water.

Tea extracts are thought to have inhibitory (in vitro and in vivo) effect against Vibrio cholerae, Salmonella typhi, Campylobacter, Helicobacter pylori, Shigella, different E. Coli types, Salmonella, Clostridium, and Candida growth, rotavirus and influenza A virus activity, pathogen enterotoxin secretion and enterotoxin-induced intestinal fluid secretion.

This inhibitory effect may occur through one or more of the following active compounds in tea and tea extracts: Catechins (present in low concentrations in black tea) , Theaflavins, Theasinensins, Thearubigins (including proanthocyanidins) .

Edible composition

The edible composition may, in principle, be of any type and may be produced by any suitable method for producing that type of composition. Beverages may also be used but the tea beverage itself is excluded from the term "edible compositions" (that is the drink that is made directly from the tea leaf being steeped in boiling water and drunk as it is or with milk added) .

The edible composition may be a cooked food product such as a cookie (biscuit) ; a bread product which can be either leavened (raised) or unleavened (unraised) , such as leavened bread, tortilla, roti, chapati, nan bread, rye-bread; pastries; cake; bun; or a snack product such as a samosa, pastie, pie, pakora, crisps etc and cereal based products such as pasta and rice- based products and bar products including snack bars and nutritional bars .

The edible composition may also be a food product which is mixed with a liquid such as milk or water during preparation. Examples of this type of edible composition include porridges and other cereal products such as breakfast cereals. Such edible compositions are generally subjected to a heating/ cooking step during their preparation. Porridges are an especially preferred type of edible composition according to the invention.

It is especially preferred that the edible composition is one that has good keeping qualities and which does not need refrigeration.

It is also preferred that the edible composition does not contain substantial amounts of water in order to extend its keeping qualities. However, for edible compositions which are conventionally in a relatively dry state such as pasta and rice based products, and those which are mixed with a liquid just prior to consumption and which are typically stored in the substantially dried state, it is not so important to have a low water content in the cooked food product .

The compositions, if they comprise the tea leaf, preferably comprise an amount of from 0.01 to 25 %wt thereof, more preferably of from 0.1 to 20 %wt, most preferably of from 0.3 to 15 %wt . The compositions, if they comprise the tea extract, preferably comprise an amount of from 0.01 to 15 %wt thereof, more preferably 0.05 to 10 %wt, most preferably, 0.1 to 5 %wt . If a mixture is used, it is especially preferred to use 0.1 to 10 %wt of the tea leaf and 0.1 to 5 %wt of the tea extract based on the weight of the composition.

Preferably the tea leaves, extract or the mixture thereof is present in the food product when it is cooked or prepared for consumption.

Any suitable ingredients may be used to produce the edible composition, depending upon the type of composition desired.

The composition may comprise a flour of which amount and type will depend upon the composition. The flour may be made, for example, from cassava, wheat, beans, rice, maize, millet or oats. If desired the composition may further comprise baking powder or any other raising agent .

The composition product may comprise a fat of some sort and the amount and type thereof will depend upon the composition. The fat may be, for example, dairy-based such as butter, cream or cheese, a vegetable oil, animal oil, nut oil etc.

The composition may comprise milk or milk based ingredients (butter is considered as a fat as referred to above) . Suitable examples include, milk and milk powder, especially skimmed milk powder. The amount and type of the milk or milk based ingredient will depend upon the composition. For sweet tasting food compositions, such as cookies, cakes, buns or pastries the inclusion of a milk or milk based ingredient, especially skimmed milk powder, provides an especially pleasing taste in combination with the tea. It is preferred that the milk or milk based ingredient is present in an amount of up to 5 or 10 %wt, more preferably of from 0.1 to 3 %wt, most preferably of from 0.5 to 2.5 % wt . in the composition. The compositions may also comprise egg in any suitable amount. The egg may be in the form of whole egg, egg whites, egg yolk or egg-derived products.

The compositions may also optionally comprise one or more natural sweeteners (sugars) . Suitable natural sweeteners include sucrose, fructose, glucose, maltose and mixtures thereof. Sucrose is especially preferred either alone or combination with another sugar. The amount of the sugar added is a matter of taste but will usually be in the range of from 1 to 25 %wt, preferably of from 2 to 20 %wt, most preferably 5 to 15% based on the weight of the composition. In some cases sugar and/or fat free products may be used.

The compositions may contain any of the usual minor food ingredients in conventional amounts, for example: flavourings including herbs and spices, salt, pepper colourings, preservatives, flavour improvers, emulsifiers, stabilisers, artificial sweeteners, aromas etc. Typically these ingredients are used in an amount of 5 %wt or less per ingredient, with the composition comprising less than 25 %wt in total of these ingredients.

Fruits and fruit pieces, vegetables and vegetable pieces, honey, cereals such as oats and rice, nuts etc may also be added to give flavour and/or texture . Depending upon the type of composition, it may comprise a fruit juice. Any desired fruit juice can be added. Typically amounts of up to 30%wt in total of these ingredients may be added. The tea and/or tea extracts are typically added to the compositions before they are cooked or prepared for consumption.

The present invention will be further explained with reference to the following non-limiting examples. Further examples within the scope of the present invention will be apparent to the person skilled in the art.

EXAMPLES

Example 1

In an in si tu experiment in which perfusion of piglet (10 kg body weight) small intestinal segments (200 cm total), 12.5 mg black tea extract per kg body weight was found effective in inhibiting ETEC- and enterotoxin-induced fluid secretion. Taking into account a 1.3x dilution of the total amount of tea consumed in the jejunum, 160 mg black tea extract per kg body weight per day is calculated to be effective for the treatment or prevention of infectious diarrhoea in humans.

Example 2

A concentration of 3 g per L black tea extract is found effective in si tu against infectious diarrhoea. A consumption of 120 mg per kg body weight black tea extract per day is calculated to be effective for the treatment or prevention of infectious diarrhoea in humans (e.g. a child of 15 kg body weight consuming 0.6 L fluids per day) .

Example 3

60 grams of biscuits comprising 3%wt of black tea extract or 9%wt of black tea consumed by a subject (e.g. a child of 15 kg body weight) such that the subject receives a daily dosage of black tea extract of 120 mg per kg body weight is effective in the treatment or prevention of infectious diarrhoea.

Example 4

100 grams of porridge comprising 2%wt of black tea extract or 6 %wt of the black tea consumed by a subject (e.g. a child of 15 kg body weight) such that the subject receives a daily dosage of black tea extract of 120 mg per kg body weight is effective in the treatment or prevention of infectious diarrhoea.

Claims

1. The use of tea leaves, tea extract or mixture thereof in the manufacture of an edible composition for use in a method of preventing or treating infectious diarrhoea, and wherein said method comprises ingesting the edible composition in an amount such that the subject consumes a daily dosage of; greater than 50 mg/kg of body weight of tea extract, or greater than 150 mg/kg of body weight of tea leaves, or greater than 100 mg/kg of body weight of a mixture of tea leaves and tea extract,

2. The use according to claim 1, wherein the subject consumes a daily dosage of 55 to 500 mg/kg of body weight of tea extract, or 165 to 1500 mg/kg of body weight of tea leaves, or 150 to 1500 mg/kg of body weight of a mixture of tea leaves and tea extract .

3. The use according to either one of claims 1 or 2 , wherein the composition comprises 0.1 to 20 %wt of tea leaves, or 0.05 to 10%wt tea extract.

4. The use according to any one of the preceding claims, wherein the composition is a cooked product selected from cookies; bread products; pastries; cakes; buns; snack products, bars, rice based products or cereal based products .

5. The use according to any one of claims 1 to 3 , wherein the composition is a porridge or breakfast cereal .