JP2003334065A - Nucleic acid complex for protecting lactic acid bacterium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a food containing viable lactic acid bacteria, needing neither costly process nor material and efficiently deliverable to the intestine through its oral administration. <P>SOLUTION: A nucleic acid complex for protecting viable lactic acid bacteria from gastric juice comprising a nucleic acid, one or more gelatinizers and water is provided. A nucleic acid complex mixture with viable lactic acid bacteria protected therein comprising said nucleic acid complex and an emulsified product prepared by emulsifying a liquid containing the viable lactic acid bacteria with an emulsifier and fat and oil is provided. A method for producing said nucleic acid complex mixture comprises mixing said emulsified product with said nucleic acid complex. A method for protecting lactic acid bacteria from gastric juice is also provided. In the above, the nucleic acid complex is preferably such one that the nucleic acid is a DNA derived from living body waste in particular and the gelatinizer(s) comprises gelatin and carrageenan. Further, said emulsifier and oil and fat preferably comprise lecithin and cacao butter respectively. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel nucleic acid complex for protecting live lactic acid bacteria, which is capable of protecting live lactic acid bacteria from gastric juice and delivering them to the intestine while keeping most of them alive, The present invention relates to a mixture containing a nucleic acid complex and a method for producing the nucleic acid complex mixture.

[0002]

2. Description of the Related Art Lactic acid bacteria are well known as a health-beneficial bacterial species present in the intestines of humans and animals. This beneficial effect of lactic acid bacteria in the intestine is harmful due to aging, the use of drugs such as antibiotics, stress, and disorders of the gastrointestinal digestive system, etc. It is reduced by the predominance of bacteria. Therefore,
Foods containing various lactic acid bacteria represented by yogurt for supplementing such useful lactic acid bacteria are on the market.
However, since many of these useful lactic acid bacteria in the intestine are sensitive to acidity, when taken orally, the gastric juice having a low pH significantly reduces the viable cell count. Therefore, in foods containing many lactic acid bacteria, the number of viable lactic acid bacteria delivered to the intestine is very small in consideration of the number of viable lactic acid bacteria contained in such foods, and the delivery efficiency is extremely poor.

[0003] When ingesting foods containing lactic acid bacterium viable bacteria such as fermented milk, many studies have been conducted to make as much lactic acid bacterium viable bacteria as possible reach the intestines. The following approach is known as a method for making as many live lactic acid bacteria as possible reach the intestine upon ingestion. The first approach is to increase the amount of lactic acid bacteria added to food. However, the addition of more lactic acid bacteria than necessary increases the cost and also affects the taste and flavor of foods. The second approach is to use acid-resistant lactic acid bacteria. Therefore, for example, there is a method of using a strain or a mutant strain having high acid resistance (for example, JP-A-58-224).
685, JP-A-5-236945). However, such a special lactic acid bacterium may affect the taste, flavor and mouthfeel of food, and may require special culture conditions. The third approach is to suppress gastric acid secretion and protect lactic acid bacteria by adding a special substance to food. For example, in JP-A-5-207846, by adding and containing a peptide fraction having a gastric acid secretion inhibitory effect separated from milk to fermented milk or a lactic acid bacterium beverage, the gastric acid secretory activity in the stomach is suppressed, and the lactic acid bacterium is treated in the stomach. Disclosed is a fermented milk or lactic acid bacterium beverage that reaches the intestine while maintaining its activity without being killed. However, the preparation of such special materials requires additional steps and is costly. A fourth approach is to coat the lactic acid bacterial cell powder with a substance that does not dissolve in gastric juice to protect it from gastric juice. For example, Japanese Patent Laid-Open No. 5-186336 discloses
Disclosed is an enteric-coated granulated product, which comprises coating a dry lactic acid bacterium powder with a layer containing fats and oils, an excipient and a hydrous alcohol-soluble protein and a layer containing a hydrous alcohol-soluble protein. The product is assumed to ingest lactic acid bacteria as a dry product (powder). On the other hand, in the present invention, an oil and fat and an emulsifier are added to a liquid containing live lactic acid bacteria to emulsify the liquid, and the obtained emulsion is composed of nucleic acid that is difficult to digest in the stomach, a gelling agent and water. It is based on the new finding that live lactic acid bacteria can be protected from gastric juice by mixing a water-insoluble complex.

[0004]

That is, the object of the present invention is to enable efficient intestinal delivery by ingestion of useful live lactic acid bacteria without the need for costly special steps or materials. It is an object of the present invention to provide a new method for protecting live lactic acid bacteria in a liquid from gastric juice for the purpose of providing food. Specifically, the object of the present invention is to provide a material for protecting live lactic acid bacteria in a liquid containing live lactic acid bacteria,
Providing a food material that protects live lactic acid bacteria that is easy to provide as a liquid or semi-liquid food using the material, a system for protecting live lactic acid bacteria in a liquid containing live lactic acid bacteria, and live lactic acid bacteria Another object of the present invention is to provide a method for producing a food material in which live lactic acid bacteria are protected from a liquid containing.

[0005]

Means for Solving the Problems The present inventors have found that nucleic acid is not easily decomposed in the stomach because no nucleolytic enzyme is present in the gastric juice, and the single-stranded DNA has many phosphate groups. Since DNA is known to be a polyanion natural polymer, attention has been paid to forming a water-insoluble gel-like complex by reacting with a gelling agent such as gelatin which is a polycation polymer. As a material for protecting live lactic acid bacteria from gastric juice, they have found nucleic acids. Also,
A mixture of this nucleic acid, a gelling agent and water was added to a liquid containing viable lactic acid bacteria emulsified with an oil and fat and an emulsifier to prepare a nucleic acid complex. The number was found to be much more protected than the untreated one, thus completing the present invention.

The invention therefore relates to a nucleic acid complex for protecting live lactic acid bacteria from gastric juice, which comprises a nucleic acid, one or more gelling agents and water. The present invention also relates to an emulsion obtained by emulsifying a liquid containing live lactic acid bacteria with an emulsifier and an oil and fat, and a nucleic acid complex mixture in which live lactic acid bacteria containing the nucleic acid complex according to claim 1 are protected. The above-mentioned nucleic acid complex mixture can be said to be a protection system for live lactic acid bacteria.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A first aspect of the present invention is a nucleic acid complex containing a nucleic acid and one or more gelling agents and water for protecting live lactic acid bacteria. The nucleic acid used in the nucleic acid complex of the present invention may be of various embodiments, for example double-stranded, single-stranded or circular DNA or RNA.
May be Sources of DNA are various organisms such as animals, plants and microorganisms. In particular, fish, which is a waste product of fishery processing, in particular, salmon, herring, and cod testis (spores) contain a large amount of nucleic acid components, so it is not possible to use nucleic acids derived from these testes from the viewpoint of recycling waste. desirable.
Further, those obtained from thymus of mammals or birds, for example, cow, pig, chicken, etc. can be used. As an example of RNA, RNA obtained from yeast can be mentioned. Furthermore, synthetic DNA and synthetic RNA can also be used.

Further, the gelling agent used in the nucleic acid complex of the present invention is a polycationic polymer capable of reacting with a nucleic acid to form a water-insoluble gel-like complex. For example, a gelling agent selected from gelatin, carrageenan, pectin, agar, duran gum, xanthan gum and the like, and a mixture thereof. A mixture of two or more gelling agents is preferred,
Particularly preferred is a mixture of gelatin and carrageenan.

A particularly preferable nucleic acid complex for protecting live lactic acid bacteria emulsified with an emulsifier and oil is a nucleic acid complex obtained by mixing any of the above DNAs with a mixed aqueous solution of carrageenan and gelatin. . The preferable mixing ratio of the nucleic acid in the nucleic acid complex is about 2.5% by weight to about 10% by weight, preferably 3% by weight to 6% by weight, based on the total amount of the nucleic acid complex components. In addition, the blending ratio of the total amount of the gelling agent in the nucleic acid complex is about 3% by weight to about 20% by weight, preferably 6% by weight to 15% by weight, based on the total amount of the nucleic acid complex components.

In a second aspect of the present invention, a nucleic acid complex prepared from the nucleic acid, one or more gelling agents and water is mixed with a liquid containing lactic acid bacterium viable bacteria emulsified with an emulsifying agent and oil. This is a mixture of nucleic acid complexes obtained by protecting live lactic acid bacteria. This nucleic acid complex mixture is in the form of gel and can be easily prepared as a fermented dairy product such as a yogurt product.

The lactic acid bacterium used in the present invention is generally preferably a lactic acid bacterium which is widely used in fermented milk such as yogurt and fermented dairy products such as lactic acid bacterium beverages as a lactic acid bacterium active in the intestine. For example, the so-called Bifidobacterium genus Bifidobacterium [eg Bifidobacterium B. bifidum), Bifidobacterium breve (B. breve), Bifidobacterium infantis (B. infantis), B. adolesenti
s), Bifidobacterium longum (B. longam)
Etc.], and also the genus Lactobacillius [eg Lactobacillus bulgaricus]
Lactobacillus acidophilus,
Lactobacillus casei (L. casei.), Lactobacillus brevis (L. brevis) Lactobacillus plantarum (L. plantarum), Lactobacillus salvarius (L.
salivarius), Lactobacillus fermentum (L.fe)
rmentum), Lactobacillus reuteri (L. reuteri)
Etc.], Streptococcus genus [eg Streptococcus faecalis,
Streptococcus thermophilu
s), Streptococcus lactis
Etc.], and the genus Enterococcus [eg, Enterococcus faecalis, etc.], but is not limited thereto. These lactic acid bacteria can be used in liquids containing viable bacteria, especially aqueous solutions. Therefore, it is not necessary to previously treat the cells with a coating or the like. As the liquid containing live lactic acid bacteria, for example, gel-like or liquid yogurt and lactic acid bacterium beverage can be used as they are. Although the present invention is characterized in that lactic acid bacteria viable bacteria can be used, conventionally known lactic acid bacterium cell powder and the like,
Of course you can use it as well.

Examples of emulsifiers for emulsifying a liquid containing viable lactic acid bacteria include lecithin, glycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester and the like. Of these, lecithin is preferred. Oils and fats used with emulsifiers include cocoa butter, palm oil, coconut oil, soybean oil,
Solid fats and edible waxes such as vegetable oils and fats such as rapeseed oil or hardened oils obtained by hardening them, and animal fats and oils such as whale oil, lard and beef tallow. Cocoa butter is most preferred. The preferable mixing ratio of the liquid containing the emulsifier, the oil and fat, and the viable lactic acid bacteria in the emulsion is 100% by weight,
Oil and fat 20 to 60% by weight, emulsifier 0.01 to 10
20 to 60% by weight of a liquid containing the same by weight and viable lactic acid bacteria.

Of the nucleic acid complex mixture of the present invention obtained by appropriately combining the above-mentioned components, the most preferable one is emulsified yogurt containing live lactic acid bacteria in cocoa butter which is an oil and fat, using lecithin as an emulsifier. The yogurt emulsion is obtained by mixing any of the above DNAs with a mixed aqueous solution of carrageenan and gelatin.

A third aspect of the present invention is to emulsify a liquid containing viable lactic acid bacteria with an emulsifier and oil and fat, and to obtain an emulsion, which is a nucleic acid complex containing nucleic acid, one or more gelling agents and water. The present invention relates to a method for producing a nucleic acid complex mixture in which live lactic acid bacteria are protected by mixing with a body. Examples of preferable lactic acid bacteria, emulsifiers, oils and fats, nucleic acids and gelling agents used in this production method are the same as those described above.
In a preferred production method, cocoa butter as an oil and fat and lecithin as an emulsifier are mixed at about 30 ° C. to about 40 ° C., preferably 35 ° C., and the liquid mixture containing viable lactic acid bacteria is added to the mixed liquid stirred at this temperature. Is gradually added dropwise to prepare a W / O emulsion of this yogurt, and this emulsion is cooled to about 2 ° C. to about 10 ° C., preferably about 4 ° C. and solidified. The resulting solid is ground in a mortar, preferably with a thickening agent such as starch, and the resulting powder is
A nucleic acid complex mixture is prepared by adding to a complex mixture solution prepared from DNA, carrageenan, gelatin and distilled water while stirring. The mixing ratio of the emulsified live lactic acid bacterium mixture (solid content basis) and the nucleic acid complex mixture is preferably 1:10 to 1:50.

Further, the present invention emulsifies a liquid containing viable lactic acid bacteria with an emulsifier and fats and oils, and the resulting emulsion contains nucleic acid and 1
It also relates to a method for protecting live lactic acid bacteria from gastric juice by mixing with a nucleic acid complex containing a gelling agent of one or more kinds and water to form a nucleic acid complex mixture in which live lactic acid bacteria are protected. Preferably, a liquid containing live lactic acid bacteria is emulsified in cocoa butter using lecithin as an emulsifier, and the obtained emulsion is combined with any of the above DNAs and one or more gelling agents, preferably carrageenan and gelatin. It is a method for protecting live lactic acid bacteria by mixing with a nucleic acid complex mixture containing water and water.

Since the nucleic acid complex mixture of the present invention is a gel-like substance, it may be used as it is, or another conventional seasoning,
By adding a mixture of flavors, sweeteners, fruits and the like or by processing with other fermented milk or the like, it can be used as a fermented dairy product, particularly a drinkable or edible yogurt product. Further, by changing or adjusting the mouthfeel and fluidity, as a material for fermented foods that further utilize live lactic acid bacteria, for example, various lactic acid bacterium fermented drinks and frozen yogurt, ice cream, jelly, candy, gummi, etc. It can also be applied to health foods, medicines, and the like.

[0017]

The present invention is limited to the following examples.
Without further explanation. I. Examination of nucleic acid complex preparation conditions A nucleic acid complex suitable for use as the nucleic acid complex of the present invention
The following experiment was conducted in order to examine the preparation conditions for coalescence.
DNA uses DNA-Na salt of Salde
However, use other reagents from Wako Pure Chemical Industries, Ltd.
It was1. Effect of pH on DNA-gelatin complex formation Aqueous DNA solution (5% w / w) and gelatin (5% w / w)
And mix with various pH sodium phosphate buffers.
Absorbance was measured at 570 nm in each case. Clear aqueous solution
When water-insoluble matter is generated in it, the absorbance at 570 nm becomes
Since it increases due to light scattering, the measured absorbance
It is presumed whether more complex was formed. Experimental
As a result, the absorbance of the mixed solution is clearly D in the area below pH 4.
It is higher than the absorbance of NA aqueous solution and gelatin aqueous solution itself.
It was This causes DNA and gelatin to react at pH 4 or below.
It was suggested that

2. DNA, gelatin and carrageenan
Effect of stability (acid resistance) of a nucleic acid complex consisting of
DNA, gelatin, and carrageenan were mixed with fruit water in a mixed nucleic acid complex containing different amounts of methyl orange, and the amount of methyl orange released from each complex in the artificial gastric juice described below was measured. A simulated digestion test was conducted to estimate the synergistic effect of acid resistance. The nucleic acid complex is the following combination: (1) DNA (5 g) + gelatin (10 g), (2) Gelatin (10 g) + carrageenan (0.3 g), (3)
DNA (5 g) + gelatin (10 g) + carrageenan (0.3 g). Each contains 100 g of distilled water. By adding 0.015 g of methyl orange to each complex, add 1.0 g of each of the complex contained in the complex to the artificial gastric fluid, gently rotate it, and collect the synthetic gastric fluid at regular intervals (30 minutes). Then, the absorbance at 509 nm is measured. This absorbance is directly proportional to the concentration of methyl orange. As a result of the measurement, in the case of the complex of DNA + gelatin + carrageenan, the release of methyl orange could be maintained for 2 hours or more. However, in both the DNA + gelatin complex and the gelatin + carrageenan complex, the release of methyl orange was completed within 30 minutes. Therefore, DNA and 2
It has been found that the complex consisting of the seed gelling agent (gelatin + carrageenan) is more stable and can retain the functional substance for a longer time.

3. Of DNA content on the stability of the complex
Effect Carrageenan (0.1 g), gelatin (3.5 g), distilled water (30 g) and the total amount of the complex components, given DNA content (0%, 2.5%, 5%, 7% and 10%).
%) Complex was prepared. The obtained complex was subjected to a simulated digestion test in the following artificial gastric juice for 2 hours, and then the mass of the remaining insoluble matter was measured. As a result of the measurement, the stability of the complex was increased as the DNA content was increased.
It was found that when the A content was increased to 10%, the complex remained 100% and was hardly digested by artificial gastric juice. From these experimental results, a nucleic acid complex composed of DNA and a gelling agent is formed at pH 4 or lower, and it is preferable to use two or more gelling agents for acid resistance. The amount of DNA is about 2.5% to about 10% based on the total amount of the nucleic acid complex component formed with the gelling agent.
%, Preferably 5% to 8% has been found to be suitable.

II. Protection of live lactic acid bacteria by DNA complex
Effect Below, the effect of protecting the viable lactic acid bacteria by the DNA complex is shown. As a liquid providing live lactic acid bacteria, a commercially available Bulgarian yogurt LB81 ^R (manufactured by Meiji Dairy Co., Ltd.) was used. This yogurt is Lactobacillus bulgaricus 2038
Strains and live strains of Streptococcus thermophilus 1131. As the DNA, DNA-Na salt of Sarde Co. was used. Cocoa butter used a product of Merck Hoei. Other reagents used were those of Wako Pure Chemical Industries, Ltd. 1. Preparation of DNA complex mixture According to Hatschek method, cocoa butter (50% w / w) and lecithin (5% w / w) were mixed at 35 ° C, and yogurt ( 45% w / w) was gradually added dropwise to prepare a W / O emulsion of yogurt.
This emulsion was cooled to 4 ° C. and solidified. Obtained solid (1
g) was ground in a mortar with potato starch (2 g).
The powder obtained was treated with DNA (5 g), carrageenan (0.
8g), gelatin (11.5g) and distilled water (100m)
The mixture prepared in 1) was added with stirring. The resulting gel-like DNA complex mixture forms a multi-layered system.

2. Preparation of artificial gastric juice and artificial intestinal fluid Pepsin (3.2 g), NaCl (2.0 g) and concentrated hydrochloric acid (7 ml) were diluted with distilled water to a final volume of 1000 ml to prepare an artificial gastric juice with a pH of about 1.2. did. Also, K
H ₂ PO ₄ (6.9 g), pancreatin (10 g) and 0.2 M NaOH solution (190 ml) were diluted with distilled water to a final volume of 1000 ml to prepare an artificial intestinal fluid having a pH of about 7.5.

3. DNA complex mixing in simulated digestion test
Measurement of survival number of lactic acid bacteria in compound 1. After culturing the DNA complex mixture containing live lactic acid bacteria produced in 1. in artificial gastric juice at 37 ± 2 ° C. for 2 hours and artificial intestinal fluid for 6 hours, the gel mixture before and after the simulated digestion test was collected, and each of them was adjusted to 0. Dispersed in 85% NaCl solution.
The number of remaining bacteria was 37 ° C for 48 hours in agar culture medium,
The measurement was carried out by the visible bacterial drop method (CFU). The test results are shown in Table 1 below. The number of viable lactic acid bacteria was 5.20 × 10 ⁷ CFU / DNA complex mixture before the simulated digestion test.
Although it was present, when cultured for 2 hours in artificial gastric juice, 1.
It was 00 × 10 ³ CFU / g. However, when further cultured in artificial intestinal fluid for 6 hours, the number of viable lactic acid bacteria was 1.7.
It increased to 5 × 10 ³ CFU / g. This result shows that the number of viable lactic acid bacteria in the gel mixture is decreased by the acidic gastric juice, but thereafter, the viable number of lactic acid bacteria is increased in the alkaline intestinal fluid. It suggests that you can grow. On the other hand, in the control yogurt not protected by the DNA complex of the present invention, most lactic acid bacteria were killed in the artificial gastric juice.

[Table 1]

[0023]

INDUSTRIAL APPLICABILITY Since the novel nucleic acid complex of the present invention uses nucleic acid as a material, it is difficult for the stomach to digest when passing through the stomach. Therefore, this nucleic acid complex can be used as a material for protecting live lactic acid bacteria from gastric juice. Furthermore, since the nucleic acid complex as a protective material can utilize biological waste such as fish testis as a nucleic acid source, it is preferable in terms of resource recycling. The nucleic acid complex mixture comprising this nucleic acid complex and a liquid containing lactic acid bacterium viable bacteria emulsified with an oil and fat and an emulsifier can be provided as a system in which lactic acid bacterium viable bacteria are protected. Therefore, if orally ingested a food containing these nucleic acid complex mixture, or a food utilizing a system that protects lactic acid bacterium viable bacteria, the nucleic acid complex in the nucleic acid complex mixture protects lactic acid bacterium viable bacteria from gastric juice, Since more lactic acid bacteria can be delivered to the intestine while remaining alive, the intake efficiency of live lactic acid bacteria is good. As a result, when foods using such a nucleic acid complex mixture are orally ingested, the infection-preventing effect, intestinal rot-preventing effect, intestinal motility promoting effect, and immunostimulating effect of live lactic acid bacteria contained in these are sufficient. Can be expected. Further, the nucleic acid complex mixture of the present invention is in the form of gel,
As it is, it can be easily processed into liquid or gel foods and can be used as fermented dairy products such as drinkable or edible yogurt products, and it can also be used as a material for foods using other live lactic acid bacteria. You can further,
The nucleic acid complex mixture in which the viable lactic acid bacteria of the present invention is protected can be produced without using acid-resistant lactic acid bacteria or special components such as gastric acid secretion inhibiting substances, and without using complicated steps. Also, it can be produced by directly using a liquid containing live lactic acid bacteria, particularly a normal yogurt or lactic acid fermented product. Therefore, it is advantageous in terms of cost, including that the above-mentioned biological waste can be used.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) A61P 37/04 A61P 37/04 // A61K 35/74 A61K 35/74 A 47/24 47/24 47 / 26 47/26 47/36 47/36 47/42 47/42 47/44 47/44 (C12N 1/20 C12R 1: 225 C12R 1: 225) 1:44 (C12N 1/20 C12R 1:44) ( 72) Inventor Liu Mudong 1-2-12, Kita, Higashi-ku, Sapporo-shi, Hokkaido 1-21-1120 (72) Inventor Masashi Matsunaga 4-11-7 F-term Odaira, Sumida-ku, Tokyo (reference) 4B018 LB07 MD86 MF02 MF14 4B065 AA30X AA49X BD06 BD35 CA41 CA44 4C076 BB01 CC07 CC16 CC31 CC40 DD63F DD66Q EE30P EE42P EE53F FF63 4C087 BC56 CA09 MA05 MA52 NA05 ZA69 ZB09 ZB32

Claims (12)

[Claims] 1. A nucleic acid complex for protecting live lactic acid bacteria, which comprises a nucleic acid, one or more gelling agents, and water. 2. A nucleic acid complex mixture protected with viable lactic acid bacteria, which comprises an emulsion obtained by emulsifying a liquid containing viable lactic acid bacteria with an emulsifier and oil and fat, and the nucleic acid complex according to claim 1. 3. A method comprising emulsifying a liquid containing live lactic acid bacteria with an emulsifier and fats and oils, and further mixing the emulsion with a nucleic acid complex consisting of nucleic acid, one or more gelling agents and water. The resulting protection system for live lactic acid bacteria. 4. The nucleic acid complex according to claim 1, wherein the nucleic acid is DNA. 5. The nucleic acid complex according to claim 4, wherein the DNA is derived from fish testis. 6. The nucleic acid complex according to claim 1, wherein the gelling agent is a mixture of carrageenan and gelatin. 7. The nucleic acid complex mixture according to claim 2, wherein the liquid containing live lactic acid bacteria is yogurt. 8. The nucleic acid complex mixture according to claim 2, wherein the emulsifier is lecithin. 9. The nucleic acid complex mixture according to claim 2, wherein the oil or fat is cocoa butter. 10. A food containing the nucleic acid complex mixture according to claim 2. 11. A method comprising emulsifying a liquid containing live lactic acid bacteria with an emulsifier and an oil and fat, and mixing the resulting emulsion with a nucleic acid complex containing nucleic acid, one or more gelling agents and water. , A method for producing a nucleic acid complex mixture in which live lactic acid bacteria are protected. 12. A lactic acid bacterium is prepared by emulsifying a liquid containing live lactic acid bacteria with an emulsifier and fats and oils, and mixing the obtained emulsion with a nucleic acid complex containing nucleic acid, one or more gelling agents and water. A method for protecting live lactic acid bacteria from gastric juice by using a nucleic acid complex mixture in which live bacteria are protected.