Composition for promoting the growth of Akkermansia muciniphila, containing dietary fiber

Abstract

To provide means for efficiently promoting the proliferation of Akkermansia muciniphila, known as slimming bacteria, in human enteric bacteria.SOLUTION: This invention has been completed with the findings that dietary fibers generally promote the proliferation of Akkermansia muciniphila.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a composition for promoting the growth of Akkermansia muciniphila containing dietary fiber.

Background Art

[0002] Dietary fiber is a component in food that cannot be digested by human digestive enzymes. Dietary fiber includes insoluble dietary fiber that is insoluble in water, represented by cellulose contained in wheat bran, and water-soluble dietary fiber that is soluble in water, represented by pectin contained in fruits. Hitherto, it has been found that dietary fiber is useful for preventing constipation by increasing the amount of feces, and recently, it has also been found that it is useful for preventing lifestyle-related diseases such as myocardial infarction, diabetes, and obesity. However, its mechanism of action is often not well understood.

[0003] In addition, from recent studies on intestinal bacteria, Akkermansia muciniphila has been reported as a new intestinal bacterium that contributes to the health of the host. Akkermansia muciniphila is a bacterium known as a so-called slimming bacterium among human intestinal bacteria, and means for efficiently growing Akkermansia muciniphila have been desired in various fields such as the food field including health foods.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention aims to provide a means for efficiently cultivating Akkermansia muciniphila, known as a "lean bacterium" in the human gut. [Means for solving the problem]

[0006] As a result of diligent research to solve the above problems, the present inventors discovered that dietary fiber promotes the growth of Akkermansia muciniphila, and thus arrived at the present invention.

[0007] In other words, the present invention is as follows: [1] A composition containing dietary fiber for promoting the growth of Akkermansia muciniphila. [2] The growth-promoting composition according to [1], wherein the dietary fiber is water-soluble dietary fiber. [3] The growth-promoting composition according to [2], wherein the water-soluble dietary fiber is selected from the group consisting of konjac flour, indigestible dextrin, polydextrose, isomaltodextrin, guar gum hydrolysate, inulin, and β-glucan. [4] The growth-promoting composition according to [1], wherein the dietary fiber is insoluble dietary fiber. [5] The growth-promoting composition according to [4], wherein the insoluble dietary fiber is insoluble glucomannan. [6] The growth-promoting composition according to [1], wherein the dietary fiber is a mixture of water-soluble and insoluble glucomannan or psyllium seed husk. A food product containing any of the compositions described in [7][1] to [6]. A method for promoting the growth of Akkermansia muciniphila, comprising administering to Akkermansia muciniphila a growth-promoting composition described in any of [8][1] to [6]. [Effects of the Invention]

[0008] The present invention provides a composition for promoting the growth of Akkermansia muciniphila, which contains dietary fiber. By promoting the growth of Akkermansia bacteria, which are intestinal bacteria, it is possible to exert effects such as inhibiting lipid absorption and resulting in weight loss. [Brief explanation of the drawing]

[0009] [Figure 1] This study demonstrates the effect of administering various dietary fibers in a liquid culture medium on promoting the growth of Akkermansia muciniphila. [Figure 2] This study demonstrates the growth-promoting effect of various dietary fibers on agar plates on Akkermansia muciniphila. Colony count (colony-forming units (CFU)) was measured. [Modes for carrying out the invention]

[0010] One embodiment of the present invention is a composition for promoting the growth of Akkermansia muciniphila, which contains dietary fiber.

[0011] The dietary fiber may be soluble dietary fiber, insoluble dietary fiber, or mixed dietary fiber containing both soluble and insoluble dietary fiber.

[0012] When the dietary fiber is water-soluble dietary fiber, it is not particularly limited as long as it does not hinder the effects of this embodiment, but can be selected from the group consisting of, for example, konjac powder, indigestible dextrin, polydextrose, isomaltodextrin, guar gum hydrolysate, inulin, and β-glucan. Preferably, the water-soluble dietary fiber is konjac powder, guar gum hydrolysate, or β-glucan.

[0013] When the dietary fiber is insoluble dietary fiber, it is not particularly limited as long as it does not interfere with the effects of this embodiment, but for example, it can be selected from the group consisting of insoluble glucomannan, chitosan, cellulose, and agar. Preferably, the insoluble dietary fiber is insoluble glucomannan.

[0014] When the dietary fiber is a mixed-type dietary fiber, it is not particularly limited as long as the effects of the present embodiment are not hindered. Examples include water-soluble and insoluble mixed glucomannan or psyllium husk. Here, the content ratio of the water-soluble dietary fiber to the insoluble dietary fiber in the water-soluble and insoluble mixed dietary fiber may be, for example, the water-soluble dietary fiber at a concentration of 8 to 50% by weight and the insoluble dietary fiber at a concentration of 50 to 92% by weight, the water-soluble dietary fiber at a concentration of 10 to 50% by weight and the insoluble dietary fiber at a concentration of 50 to 90% by weight, the water-soluble dietary fiber at a concentration of 20 to 50% by weight and the insoluble dietary fiber at a concentration of 50 to 80% by weight, the water-soluble dietary fiber at a concentration of 30 to 50% by weight and the insoluble dietary fiber at a concentration of 50 to 70% by weight, the water-soluble dietary fiber at a concentration of 40 to 50% by weight and the insoluble dietary fiber at a concentration of 50 to 60% by weight, the water-soluble dietary fiber at a concentration of 10 to 40% by weight and the insoluble dietary fiber at a concentration of 60 to 90% by weight, the water-soluble dietary fiber at a concentration of 10 to 30% by weight and the insoluble dietary fiber at a concentration of 70 to 90% by weight, or the water-soluble dietary fiber at a concentration of 10 to 20% by weight and the insoluble dietary fiber at a concentration of 80 to 90% by weight. Also, the weight ratio of the water-soluble dietary fiber to the insoluble dietary fiber in psyllium husk is not particularly limited as long as the effects of the present embodiment are not hindered.

[0015] The origin of the dietary fiber is not particularly limited as long as the effects of the present embodiment are not hindered. For example, it may be derived from konjac.

[0016] The dietary fiber may be a commercially available product or may be produced by a method known to those skilled in the art.

[0017] The shape of the dietary fiber is not particularly limited as long as the effects of the present embodiment are not hindered. For example, it may be powdery or thin film片状, or may be in a liquid or paste form in which the dietary fiber is mixed with an arbitrary solvent.

[0018] The content of dietary fiber in the composition of the present embodiment is not particularly limited as long as it does not prevent the effects of the present embodiment. For example, it may be 50% or more, 80% or more, 90% or more, 95% or more, or 98% or more based on the total weight of the composition.

[0019] The intake amount of the composition of the present embodiment is not particularly limited as long as it does not prevent the effects of the present embodiment. For example, in the case of a human weighing 60 kg, the amount of dietary fiber may be 3 g or more, 3.5 g or more, 5 g or more, 7 g or more, 10 g or more, 15 g or more, 20 g or more, or 30 g or more per day. There is no particular upper limit, but for example, it is 100 g or less.

[0020] The intake period of the composition of the present embodiment is not particularly limited as long as it does not prevent the effects of the present embodiment. For example, it may be 1 day or more, 2 days or more, 3 days or more, 5 days or more, 1 week or more, 2 weeks or more, 3 weeks or more, 1 month or more, 2 months or more, 3 months or more, 6 months or more, or 1 year or more.

[0021] The intake route of the composition of the present embodiment is not particularly limited as long as it does not prevent the effects of the present embodiment. Preferably, it is oral intake.

[0022] The composition of the present embodiment may contain additional components as long as it does not prevent the effects of the present invention. For example, components for food or components having other health-promoting effects are exemplified.

[0023] Another embodiment of the present invention is a food containing any of the above compositions. The food product is not particularly limited as long as it does not hinder the effects of the present invention, and can be used in all kinds of food and beverages. Specifically, examples include beverages such as drinking water, soft drinks, various soups, and various energy drinks, as well as foods containing a lot of water such as jelly and yogurt. However, the above composition can also be used by kneading it into dough during the processing of confectionery, bread, noodles, etc. Various foods can be manufactured by combining the above composition with ingredients according to the type of food. The amount of the above composition in a food product is not particularly limited, but the amount of dietary fiber can be, for example, 1% or more, 5% or more, 10% or more, 20% or more, or 30% or more of the total weight of the food product. Furthermore, the food can also be presented in the form of functional foods, such as foods for specified health uses, supplements, or other health functional foods that display functions such as "promoting the growth of Akkermansia muciniphila," "promoting the growth of lean bacteria," or "improving intestinal bacteria."

[0024] Another embodiment of the present invention is a method for promoting the growth of Akkermansia muciniphila, comprising administering any of the growth-promoting compositions described above to Akkermansia muciniphila. This promotion method is typically an in vitro method, or in vivo, by oral / enteral administration to non-human animals.

[0025] For example, a composition containing dietary fiber may be mixed with a culture medium at any dosage concentration, and Akkermansia muciniphila may be cultured in this mixed medium. Any dosage concentration may be, for example, 0.1 mg / ml, 0.5 mg / ml, 1 mg / ml, 5 mg / ml, 10 mg / ml, or higher. The administration period is not particularly limited as long as it does not interfere with cell proliferation, and may be 12 hours, 24 hours, 36 hours, 48 ​​hours, 72 hours, or longer.

[0026] During bacterial culture, the culture medium may be replaced as appropriate, and preferably the new culture medium to be replaced contains the composition of this embodiment.

[0027] The following describes, as a reference example, a method for producing konjac-derived insoluble glucomannan, which is an example of a desirable dietary fiber. Konjac-derived insoluble glucomannan is preferably obtained by grating konjac, dispersing it in water, and then heat-treating (drying) it. When the konjac-derived insoluble glucomannan is in liquid form, it can be produced, for example, by a method including the steps of grating konjac, dispersing the grated konjac in water to obtain a mixture, heat-treating the mixture, and homogenizing the heat-treated mixture using a homogenizer (Patent Document 1). Furthermore, if the konjac-derived insoluble glucomannan is in the form of thin film flakes, it can be produced by a method comprising the steps of grating konjac, dispersing the grated konjac in water to obtain a mixture, and drying the mixture to obtain dried grated konjac thin film flakes (Patent Document 2). Furthermore, if the konjac-derived insoluble glucomannan is in powder form, it can be manufactured by a method that includes, for example, the steps of grating konjac, dispersing the grated konjac in water to obtain a mixture (Patent Document 1), drying the mixture (Patent Document 2), and pulverizing the dried mixture (Patent Document 3).

[0028] <Method for producing liquid konjac-derived insoluble glucomannan> Liquid konjac-derived insoluble glucomannan can be produced by a method that includes, for example, the steps of grating konjac, dispersing the grated konjac in water to obtain a mixture, heat-treating the mixture, and homogenizing the heat-treated mixture using a homogenizer. The specific steps are as follows:

[0029] (The process of grating konjac) In the process of grating konjac, konjac is used as the raw material and is subjected to at least grinding and dewatering treatment. The type of konjac used here is not particularly limited, and any type of konjac can be used, such as konjac in sheet form, konjac in the shape of thread, or shirataki noodles.

[0030] Konjac can be obtained by dissolving konjac powder in water, adding a coagulant to the swollen konjac paste (so-called konjac glue), and then heating it to gel. The concentration of konjac powder in the konjac paste may be in the range of 2.0% to 3.5% by weight. The temperature of the water used to dissolve the konjac powder may be room temperature water or warm water up to about 70°C. In any temperature range, it is important that the konjac powder is completely dissolved in the water and swollen.

[0031] Any coagulant commonly used in konjac production, such as calcium hydroxide or sodium carbonate, can be used as a coagulant added to the konjac paste. Heating for gelation of the konjac paste can be done by immersing the paste in hot water at 80°C to 90°C or by leaving the paste in a steam atmosphere for 10 to 120 minutes.

[0032] In the process of grating konjac, the konjac is ground. The size of the ground konjac fragments is not particularly limited, as long as it is a size that does not interfere with the subsequent dehydration process and homogenization process using a homogenizer.

[0033] A grinding machine can be used for the grinding process. The grinding machine supplies the material to be ground between two grinders positioned opposite each other with a predetermined clearance between them, and the two grinders are positioned relative to each other. This method grinds the material to be ground by shearing it through rotation. By adjusting the clearance of the grinder, the size of the fragments obtained by grinding can be adjusted.

[0034] When using such a grinder for grinding, the size of the fragments can also be determined by the clearance of the grinder used in the grinder. To obtain the above size, the grinder clearance can be, for example, 0.1 mm to 0.5 mm.

[0035] Konjac can also be roughly cut before grinding. Rough cutting is a process that makes it easier to grind the konjac by cutting it into pieces small enough to feed into a grinder, for example, when grinding is done in a grinder. Therefore, if the konjac used in the production of ground konjac is of a size that does not hinder the grinding process, this rough cutting is unnecessary.

[0036] Grinding is preferably carried out with the addition of water. If rough cutting is performed prior to grinding, rough cutting may be performed without adding water, followed by grinding with water, or rough cutting may be performed with water, followed by grinding with the added water. Alternatively, rough cutting may be performed with water, the water may be drained, and then grinding may be carried out with newly added water. Furthermore, if grinding and / or rough cutting are performed following the production of konjac, these processes may be carried out immediately after heating for gelation of the konjac mixture, or after cooling.

[0037] Konjac that has been ground through a grinding process is then dehydrated to obtain grated konjac. A dehydrator can be used for the dehydration process, but the dehydration method of the dehydrator can be any method, such as a filter press method or a belt press method that uses a filter cloth, or a centrifugal separation method. For example, when dehydrating using a dehydrator that uses a filter cloth, if the size of the konjac particles after grinding is too small, the filter cloth may become clogged. Therefore, it is important to select the size of the konjac particles after grinding so that the dehydrator can perform to its full potential.

[0038] Dehydration can be combined with washing. One of the purposes of dehydration is to remove the konjac odor. Therefore, washing the finely ground konjac with water before dehydration, or repeatedly washing with water and dehydrating, can more effectively remove the konjac odor. Washing can also lower the pH of the grated konjac.

[0039] The water content of konjac after dehydration, i.e., grated konjac, is not particularly limited, but is preferably 75% to 90%.

[0040] (The process of dispersing grated konjac in water to obtain a mixture) The grated konjac obtained as described above is then dispersed in water to obtain a mixture containing at least grated konjac and water. The method of dispersing the grated konjac in water is arbitrary. The solid content concentration of the grated konjac in the mixture is preferably 1% to 6%, more preferably 2% to 5%, and even more preferably 3% to 4%.

[0041] The mixture may contain a thickening and stabilizing agent in addition to water. Examples of thickening and stabilizing agents include starch, xanthan gum, guar gum, tara gum, carrageenan, and locust bean gum, and the mixture may contain at least one of these. Furthermore, for flavoring and / or pH adjustment of the mixture containing dispersed grated konjac, the mixture may contain at least one of the following: acidulants, seasonings, spices, flavorings, fruits, vegetables, meats, and extracts. This step may also involve further finely grinding the grated konjac.

[0042] (The process of heat-treating the mixture) The mixture obtained in the above process (hereinafter also referred to as the grated konjac mixture) is heat-treated. The heating temperature can be appropriately determined according to the pH of the grated konjac mixture, and is preferably 100°C to 155°C, more preferably 120°C to 146°C, and even more preferably 130°C to 146°C. The heating time can be determined according to the heating temperature, and is, for example, 1 minute or more at 100°C, and 1 second or more at 155°C.

[0043] Either indirect heating or direct heating methods can be used. In the case of indirect heating, a tube-type sterilization device is preferably used, for example, which uses a double or triple tube, through which the mixture containing grated konjac flows in the inner tube (or the middle tube in the case of a triple tube), while a heat transfer medium flows in the outer tube (or the innermost and outermost tubes in the case of a triple tube), and the mixture containing grated konjac is heated through the tube walls by the heat transfer medium.

[0044] (A process of homogenizing a heat-treated mixture using a homogenizer.) The mixture containing heat-treated grated konjac is homogenized. A homogenizer, preferably a plunger-type homogenizer, is used for homogenization. A plunger-type homogenizer has a homogenizing valve with fine gaps, and when a fluid containing pressurized particles passes through these gaps due to the reciprocating motion of the plunger, the shear force acting on the particles homogenizes them. In this way, with a plunger-type homogenizer, the particles are made into fine particles by passing through the gaps, so the particle size of the homogenized particles has relatively little variation and is uniform. The pressure of the homogenizer is preferably 0.5 MPa or higher, more preferably 10 MPa to 200 MPa, and even more preferably 20 MPa to 100 MPa.

[0045] <Method for producing thin, flake-like insoluble glucomannan derived from konjac> Thin-film flaked konjac-derived insoluble glucomannan can be produced, for example, by a method including the steps of grating konjac, dispersing the grated konjac in water to obtain a mixture, and drying the mixture to obtain dried grated konjac thin-film flaks. The steps of grating konjac and dispersing the grated konjac in water to obtain a mixture can be adapted from the steps described in the method for producing liquid konjac-derived insoluble glucomannan described above. The other specific steps are as follows.

[0046] (A step in which the mixture is dried to obtain thin strips of dried grated konjac.) The process may include a drying step to remove moisture from the mixture and a thin-film fragmentation step to crush the hardened mixture obtained by drying to obtain thin film fragments. These drying and thin-film fragmentation steps can be carried out independently or at least partially in parallel. For example, the following methods (1) or (2) can be used. (1) A drying process to remove moisture from the mixture is carried out under conditions that yield a hardened product with the desired hardness required for the dried konjac thin film fragments. After that, the hardened product is crushed to obtain dried konjac thin film fragments. (2) The drying process to remove moisture from the mixture can also be divided into a first drying process, which is carried out until the mixture has a suitable hardness for obtaining thin film pieces, and a second drying process, which is carried out after crushing the dried material obtained in the first drying process to obtain thin film pieces, and then carrying out a further drying process to obtain the desired dried konjac thin film pieces. The drying process can be performed using a method selected from forced-air drying, reduced-pressure drying, and heat drying, depending on the purpose, and two or more of these methods may be used in combination.

[0047] To obtain the unique multilayer structure according to the present invention by drying multiple konjac fragments in a state where at least one part of each fragment overlaps, a drying process is provided which includes the steps of forming a layer of the mixture on the surface of the support (dried surface) and removing at least a portion of the moisture from the mixture layer thus obtained. This is preferable. The process of forming the mixture layer and the process of removing moisture from the mixture layer may be carried out separately or continuously. Alternatively, these processes may be carried out simultaneously. A drying step including the step of forming this mixture layer can preferably be used as the drying step in method (1) above and as the first drying step in method (2) above. The thickness of the mixture layer is not particularly limited and should be set to a degree that allows for obtaining the desired dried konjac thin film, depending on the amount of konjac fragments contained in the mixture layer. By drying the mixture layer into a thin film, a dried thin film consisting of dried konjac fragments can be obtained. The thickness of the mixture layer is preferably adjusted according to the solid content concentration of the mixture, etc., so that the final thickness of the dried konjac thin film is within the range of 5 μm to 400 μm.

[0048] As a support for forming the mixture layer, a support made of a material such as a metal with thermal conductivity for heating, in the shape of a flat plate or drum, can be used. When using a flat plate support, a partition wall having a height sufficient to obtain the desired thickness of the mixture layer may be provided to surround the planar area where the mixture layer is formed. Furthermore, a drum dryer can be used as a dryer that uses a drum-shaped support. In the drying process using a drum dryer, the mixture is applied in layers to the heatable drying surface of the drum (for example, the outer surface of the drum), and a dried thin film is formed from the mixture layer. The drum dryer is not particularly limited as long as it is capable of forming the desired dried thin film. Single-drum, double-drum, and twin-drum drum dryers can be appropriately selected and used. The mixture feeding method in the single-drum type is also not particularly limited and can be appropriately selected from dip-feed, lower-roll transfer, upper-roll feed, etc. The drying temperature and drying time of the mixture layer are set to obtain the desired degree of dryness. The drying temperature can be set to a temperature selected from, for example, 120°C to 180°C, and more preferably 130°C to 140°C. The drying time can be selected from, for example, 10 seconds to 5 minutes, but preferably 15 seconds to 3 minutes, and more preferably 20 seconds to 2 minutes. To form a more stable and efficient mixture layer on the support, as mentioned earlier, a thickening agent can be added to the mixture as needed.

[0049] The dried thin film obtained on the drying surface of the support has a shape formed by the drying surface on the surface in contact with the drying surface (bottom surface), for example, a shape that continuously or discontinuously forms a surface corresponding to the drying surface, and an irregular uneven shape derived from the konjac fragments is formed on the open surface opposite this bottom surface. Although the konjac fragments decrease in volume and deform upon drying, they maintain at least a part of the unique shape described above, which is obtained by grinding, as their basic shape, and at least a part of this unique shape is reflected in the dried konjac thin film fragments that are finally obtained.

[0050] By peeling the dried thin film from the dried surface of the support and forming it into a thin film, a dried konjac thin film piece according to the present invention can be obtained. The peeling step of the dried thin film and the thin film piece formation step may be performed separately or in sequence. To more efficiently peel a dried thin film from a support and break it into thin film fragments, it is preferable to use a continuous process that utilizes the peeling force when peeling the dried thin film from the support with a scraper, thereby simultaneously peeling the dried thin film from the support and breaking it into thin film fragments. The dried thin film formed on the support has gaps between dried grated konjac fragments, areas where the bonds between dried grated konjac fragments are weak, or areas where the dried film thickness is thin and easily torn. When peeling the dried thin film upwards from the support using a scraper, the force applied to these areas allows for automatic fragmentation of the thin film. By having a dry thin film thickness on the support within the range of 5 μm to 400 μm, the dry thin film can be more efficiently broken down into thin film flakes when peeled off with a scraper. Furthermore, the dried thin film formed on the dried surface of the support, or the dried thin film obtained from the dried thin film. The dried konjac film pieces may be in a semi-dried state, and further drying treatment may be performed as needed to obtain the desired degree of dryness. The size of the dried konjac thin film piece according to the present invention, that is, the maximum length from any one end of the dried konjac thin film piece on the same straight line to the other end, is preferably 30 to 50 mm.

[0051] <Method for producing powdered konjac-derived insoluble glucomannan> Powdered konjac-derived insoluble glucomannan can be produced, for example, by a method including the steps of grating konjac, dispersing the grated konjac in water to obtain a mixture, drying the mixture, and pulverizing the dried mixture. The steps of grating the konjac and dispersing the grated konjac in water to obtain a mixture can be adapted from the steps described in the method for producing liquid konjac-derived insoluble glucomannan described above. The step of drying the mixture can be adapted from the drying portion of the step of drying the mixture to obtain dried grated konjac film fragments described in the method for producing thin film fragments of konjac-derived insoluble glucomannan described above. The other specific steps are as follows.

[0052] (Process of grinding the dried mixture) This grinding process is not particularly limited as long as it achieves the desired grinding effect, and known grinding methods can be used for this grinding process. For example, at least one or a combination of dry grinding, wet grinding, and wet pressurizing can be used for the grinding process. When these powder particles are subjected to a grinding process to reduce their particle size, fragmentation similar to cleavage occurs, resulting in fragmented particles with reduced particle size in various shapes, such as hemispherical, flaky, or spherical shapes with parts of the sphere broken off. The particle size of the powder particles before grinding is based on the particle size of the powder particles contained in the konjac raw material powder and varies depending on the type of konjac raw material powder. However, the median value (D50 value) in the volume accumulation of the particle size distribution is usually between 300 μm and 400 μm. To obtain the above-mentioned water-holding capacity (swelling ability) and association ability, the grinding conditions are set so that the median value before grinding is reduced by grinding. The median particle size distribution of the pulverized powder is preferably 120 μm or less, more preferably 100 μm or less, and even more preferably in the range of 30 μm or more and less than 100 μm. Furthermore, the konjac powder after pulverization preferably contains powder particles with a particle size in the range of 1 μm to 300 μm, but it is acceptable if konjac powder with a particle size of 300 μm or more is mixed in. The D50 value is calculated from the particle size distribution of the powder, and the particle size distribution of the powder can be determined by known methods. The above D50 value was calculated from the particle size distribution obtained by the laser diffraction-scattering method. The particle size distribution can be measured by the laser diffraction-scattering method using a particle size distribution analyzer with the Microtrac-Bell MT3300 series (LOW-WET).

[0053] Next, a method for producing konjac-derived mixed water-soluble and insoluble glucomannan will be described as a reference example, as an example of a preferred dietary fiber. The method for producing konjac-derived mixed water-soluble and insoluble glucomannan can be based, for example, on the method described in Patent Document 4.

[0054] <Method for producing powdered konjac-derived mixed water-soluble and insoluble glucomannan> The konjac-derived mixed water-soluble and insoluble glucomannan powder according to this embodiment can be manufactured by a method comprising: (A) a mixing step of mixing konjac raw material powder with an alkali metal solution to supply the alkali metal solution to the powder particles contained in the konjac raw material powder; and (B) an insoluble glucomannan formation step of forming insoluble glucomannan in the powder particles to which the alkali metal solution has been supplied by the action of the alkali metal solution. Steps (A) and (B) described above maintain the particle form of the powder particles contained in the konjac powder, and the total glucomannan (water-soluble glucomannan and insoluble glucomannan) contained in the mixed water-soluble and insoluble glucomannan powder The process is carried out until the ratio (by weight) of insoluble glucomannan to the total amount of lucomannan is high enough that the gelling ability inherent in the konjac raw material is lost. Water-soluble and insoluble mixed glucomannan is clearly distinguished from konjac raw material powder in that it does not dissolve in water and does not have gelling ability, due to the significantly higher amount of insoluble glucomannan compared to konjac raw material powder. On the other hand, unlike conventional konjac raw material powder, water-soluble and insoluble mixed glucomannan is clearly distinguished in that it contains water-soluble glucomannan and has water-dispersibility and swelling properties.

[0055] (The process of mixing konjac raw material powder and alkali metal solution) In the method for producing a mixed type of water-soluble and insoluble glucomannan powder, first, a mixture of konjac raw material powder and an alkali metal solution is prepared. For preparing this mixture, a method of adding the alkali metal solution to the konjac raw material powder and mixing by stirring is preferably used. A known stirring mixer can be used for mixing the konjac raw material powder and the alkali metal solution.

[0056] Furthermore, when adding and mixing an alkali metal solution to konjac raw material powder, in order to maintain the particle shape of the powder particles, it is preferable to use a method of loosening the partially formed hard aggregates, which are formed by the absorption of the alkali metal solution and the aggregation and binding of particles, by stirring, etc., to separate the particles. Moreover, if more than twice the amount of alkali metal solution is added and mixed with the konjac raw material powder, it will not be possible to loosen it even by strong stirring, etc., and a sponge-like state in which aggregates are formed will occur. In this case, the particles may be separated by stirring, etc., after drying. It is also possible to separate the particles by washing with aqueous alcohol, neutralizing with acid, dehydrating, drying, etc., while the aggregates are still formed, or after the drying process.

[0057] In the method for producing a mixed type of water-soluble and insoluble glucomannan powder, the key is how to permeate the alkali metal compound into the konjac raw material powder. It is important that the alkali metal solution added to the raw material powder is completely absorbed, separating the individual powder particles. As for the konjac raw material powder, there are no particular restrictions on what can be used as long as it can produce the desired konjac powder by treatment with an alkali metal solution. For example, as the konjac raw material powder, you can use commonly used premium grade powder, first grade powder, or refined konjac powder such as Timak Mannan (Orihiro Co., Ltd.).

[0058] The alkali metal compounds included in the alkali metal solution added to the konjac raw material powder are preferably sodium compounds and potassium compounds, and at least one of these can be used. Examples of sodium compounds include sodium hydroxide; inorganic salts of sodium such as sodium carbonate, sodium bicarbonate, monosodium phosphate, disodium phosphate, trisodium phosphate, sodium pyrophosphate, sodium metaphosphate, and sodium polyphosphate; and organic salts of sodium such as monosodium citrate, disodium citrate, and trisodium citrate. Examples of potassium compounds include potassium hydroxide; inorganic salts of potassium such as potassium carbonate, potassium bicarbonate, dipotassium hydrogen phosphate, dipotassium phosphate, tripotassium phosphate, potassium metaphosphate, potassium polyphosphate, and potassium pyrophosphate; and organic salts of potassium such as tripotassium citrate. Among these, sodium hydroxide, potassium hydroxide, and sodium carbonate are preferred, and it is preferable to use these compounds individually or in combination of two or more. When using two or more alkali metal compounds in combination, a solution containing these two or more compounds can be prepared and used in the mixing process with the konjac raw material powder. Alternatively, solutions for each of these two or more compounds can be prepared and used in the mixing process with the konjac raw material powder.

[0059] An alkali metal solution contains an alkali metal compound and a liquid medium for dissolving it. Water suitable for food production can be used as the liquid medium. An aqueous solution of the alkali metal compound is preferred as the alkali metal solution. Furthermore, the alkali metal solution should not contain components such as sugar or alcohol, but consist of water and the alkali metal compound, with the alkali metal compound being the sole alkaline component; that is, an aqueous solution in which the alkaline component is an alkali metal compound is preferred. The concentration of the alkali metal compound in the alkali metal solution is not particularly limited and is set so as to obtain the desired conversion rate of water-soluble glucomannan to insoluble glucomannan contained in the konjac raw material powder. The concentration of the alkali metal compound in the alkali metal solution can be selected from the range of 0.1M to 5.0M, but it is preferably selected from the range of 0.1M to 3.0M, more preferably from the range of 0.2M to 2.0M, and even more preferably from the range of 0.2M to 1.0M. Furthermore, the pH of the alkali metal solution is not particularly limited as long as it is set so that the desired conversion rate of water-soluble glucomannan to insoluble glucomannan contained in the konjac raw material powder is obtained, but it is preferable to select it from a range of 11.0 to 14.0, for example. The amount of alkali metal solution added to the konjac raw material powder should be selected from a range that allows the powder particles contained in the konjac raw material powder to maintain their particle shape, while achieving the desired conversion ratio of glucomannan to insoluble glucomannan contained in the konjac raw material powder. It is preferable to select the amount of alkali metal solution to add to the konjac raw material powder based on the concentration of alkali metal compounds contained in the alkali metal solution and the amount of water supplied from the alkali metal solution to the konjac raw material powder. By adding an alkali metal solution in an amount preferably 0.5 to 10 times, more preferably 0.5 to 5 times, and even more preferably 0.5 to 1.5 times (by weight) relative to the amount of konjac raw material powder, it is possible to absorb the alkali metal solution into the powder particles while maintaining the shape of the powder particles.

[0060] (Insoluble glucomannan formation process) This process involves maintaining the temperature and time necessary for the formation of insoluble glucomannan by stirring the mixture obtained in the mixing step, or by allowing it to stand, as needed, thereby promoting the formation of insoluble glucomannan and obtaining a glucomannan powder containing both water-soluble and insoluble glucomannan with an increased proportion of insoluble glucomannan. In the insoluble glucomannan formation process, an alkali metal solution is supplied to the powder particles contained in the konjac raw material powder, and insoluble glucomannan is formed from water-soluble glucomannan within the powder particles, that is, on the surface and in at least a portion of the interior of the powder particles.

[0061] The mixing step and the insoluble glucomannan formation step can be partially overlapped or performed simultaneously. When adding and absorbing alkali metal compounds to the raw material powder during the mixing process, moderate heating is preferable to promote the conversion of glucomannan to insoluble glucomannan. The temperature for heating is not particularly limited, but it is preferable to select a temperature in the range of 5°C to 80°C, preferably 30°C to 70°C. Subsequently, the conversion to insoluble glucomannan may be promoted by performing an insoluble glucomannan formation process, which involves holding the mixture at room temperature or moderately heated to about 5°C to 80°C for several hours to several days. Furthermore, the conversion to insoluble glucomannan can also be promoted during a drying process at 80°C or below, and the conversion reaction to insoluble glucomannan may even be stopped by drying.

[0062] Maintaining the particle form of the powder particles means that, through the processing steps with alkali metal solution, including the mixing step and the insoluble glucomannan formation step described above, the powder particles contained in the konjac raw material powder maintain their primary particle state regardless of whether or not there are changes in the external shape or size of the particles. This means maintaining the state, and may include cases where powder particles swell due to the penetration of alkali metal solution into the powder particles, or where powder particles shrink due to the release of moisture or other substances outside the powder particles, or where changes occur in the particle shape or size. In the mixing process of konjac raw material powder and alkali metal solution and the process of forming insoluble glucomannan within the powder particles, the konjac raw material powder is processed in a powder state to become konjac powder, and the shape of the powder particles is maintained during this process.

[0063] The insoluble glucomannan formation process is terminated when the desired conversion of glucomannan to insoluble glucomannan is achieved. Whether the desired konjac powder has been obtained can be confirmed by measuring the content and ratio of water-soluble and insoluble glucomannan, measuring viscosity, and observing the dispersion state in water or warm water. When setting the completion time for the insoluble glucomannan formation process using the content ratio of water-soluble glucomannan to insoluble glucomannan, it is possible to measure the content ratio of water-soluble glucomannan to insoluble glucomannan in konjac powder obtained under various processing conditions, pre-select processing conditions that can obtain the desired content ratio, and then process the konjac raw material powder under the selected processing conditions. By sampling a test sample from konjac powder during the alkali metal solution treatment process and measuring the viscosity of the resulting aqueous dispersion, and further by observing the dispersion state in the aqueous dispersion, the completion time of the insoluble glucomannan formation process can also be confirmed. When the proportion of insoluble glucomannan to total glucomannan increases and the gelling ability is lost, the konjac powder does not dissolve in the aqueous dispersion and maintains its granular state, and the viscosity of the aqueous dispersion remains constant and does not increase. For example, as shown in the experimental examples and embodiments described later, an aqueous dispersion of konjac powder with no gelling ability at a predetermined concentration maintains a low viscosity state of 200 mPa·s or less. Thus, the maintenance of a low viscosity state can be used as an indicator of the loss of gelling ability. Furthermore, as the proportion of insoluble glucomannan to total glucomannan used as an indicator of the loss of gelling ability, a ratio of 50% by weight or more is preferably used.

[0064] The mixture of konjac raw material powder and alkali metal solution maintains a wet powder state during and after the processing step with the alkali metal solution. Washing and drying steps may be added as needed to the resulting wet powder or the dried powder obtained by drying the wet powder. The washing step may be used as a step to terminate the process and stop the action of the alkali metal solution. Furthermore, it is preferable to add a grinding process (including fine grinding) during or after at least one of the washing, drying, and neutralization steps described later, to reduce the particle size of the powder particles and improve their dispersibility and swelling properties. These processes are not particularly limited as long as they achieve the desired reduction in particle size. Known methods can be used for these processes. For example, the grinding process can utilize at least one of dry grinding, wet grinding, and wet pressurizing, or a combination of several different methods. In the grinding process, the most important thing is to adjust the particle size in order to ultimately obtain konjac powder with water-holding capacity.

[0065] In a mixed glucomannan powder containing both water-soluble and insoluble glucomannan, obtained by converting a portion of the water-soluble glucomannan into insoluble glucomannan while maintaining the particle shape of the raw material powder particles, it is believed that the outer shell of each powder particle mainly contains insoluble glucomannan, while the interior mainly contains water-soluble glucomannan. When these powder particles are subjected to a grinding process to reduce their particle size, fragmentation similar to cleavage occurs, resulting in fragmented particles with reduced particle size in shapes such as hemispherical, flaky, or partially broken spherical shapes. In other words, the outer shell containing the insoluble glucomannan of the powder particles is partially scraped or divided, reducing the particle size of the powder particles. The resulting fragments, i.e., the water-soluble and insoluble glucomannan in the konjac raw material powder, are converted to insoluble glucomannan by an alkaline agent while maintaining the shape of the powder. In the case of pulverized mixed glucomannan, the portion containing water-soluble glucomannan within the powder particles before pulverization becomes more easily exposed, which is thought to result in konjac powder that can more effectively utilize both water-soluble and insoluble glucomannan. Powder particles that have undergone such pulverization are a particularly preferable form for utilizing the properties and physiological functions of both water-soluble and insoluble glucomannan. In glucomannan powder containing both water-soluble and insoluble components after such grinding (ground product of glucomannan powder containing both water-soluble and insoluble components), both water-soluble and insoluble glucomannan are effectively utilized to more effectively acquire water-holding capacity (swelling ability) due to water absorption and association characteristics in which multiple powder particles associate with weak bonding forces in water. These properties are not observed in the powder particles before grinding, or are stronger than those of the powder particles before grinding. In addition to the particle size distribution, the behavior of these properties in water can also be observed to distinguish between powder particles before and after grinding. The particle size of the powder particles before grinding varies depending on the type of konjac raw material powder, based on the particle size of the powder particles contained in the konjac raw material powder. However, the median value (D50 value) in the volume accumulation of the particle size distribution is usually between 300 μm and 400 μm. When obtaining a glucomannan powder with a mixture of water-soluble and insoluble particles of this size, it is preferable to use a method of setting the grinding conditions so that the median value before grinding is reduced by grinding in order to obtain the above-mentioned water-holding capacity (swelling ability) and association ability. The median particle size distribution of the pulverized powder is preferably 120 μm or less, more preferably 100 μm or less, and even more preferably in the range of 30 μm or more and less than 100 μm. Furthermore, the konjac powder after pulverization preferably contains powder particles with a particle size in the range of 1 μm to 500 μm, but it is acceptable for konjac powder with a particle size exceeding 500 μm to be mixed in as long as it does not impair water dispersion and swelling properties.

[0066] Furthermore, in the mixed water-soluble and insoluble glucomannan powder after grinding, it is preferable that the proportion of total glucomannan in the powder particles be 50 to 98% by weight, similar to the mixed water-soluble and insoluble glucomannan powder before grinding. Regarding the lower limit of the total glucomannan proportion, 80% by weight or more is more preferable, and 90% by weight or more is particularly preferable.

[0067] Furthermore, it is preferable that the ratio of water-soluble dietary fiber to insoluble dietary fiber be within the range that includes the ratio in fibrous vegetables including cabbage, i.e., 8 to 50% by weight of water-soluble dietary fiber and 50 to 92% by weight of insoluble dietary fiber.

[0068] As a cleaning agent for washing konjac powder, any cleaning agent that can wash away excess alkali metal compounds that were not used in the conversion of glucomannan to insoluble glucomannan, i.e., dealkalize the konjac powder, can be used without limitation. As a cleaning agent, for example, alcohol-containing water containing 10 to 50% by weight of a volatile alcohol such as ethanol is preferred, and alcohol-containing water containing 10 to 35% by weight of a volatile alcohol is more preferred.

[0069] A neutralization step using an acid may be added during or after the washing process as needed. The acid used for neutralization is preferably one used as an acidic component in acidifying agents used in food. Examples of such acids include organic acids such as citric acid and malic acid, or inorganic acids such as hydrochloric acid, phosphoric acid, and phosphates. The acid can be added to the washing solution in powder or particulate form, or used as an aqueous solution for the neutralization treatment. The acid concentration should be selected to achieve the desired neutralization effect. For example, an aqueous solution with an acid concentration of 1 to 10% by weight is preferably used. Furthermore, in the process of washing the aforementioned mixed water-soluble and insoluble glucomannan powder, a wet pressurized processing treatment may be added for purposes such as improving washing efficiency.

[0070] The drying process is carried out according to the moisture content of the desired mixed water-soluble and insoluble glucomannan powder. This can be carried out under certain conditions and using a known powder drying apparatus. The moisture content of the mixed water-soluble and insoluble glucomannan powder after the drying process can be, for example, 10% by weight or less, preferably in the range of 2 to 8% by weight. [Examples]

[0071] The present invention will be described below using examples, but the present invention is not limited to these examples.

[0072] <Methods for obtaining or manufacturing various types of dietary fiber> Konjac powder was obtained from Orihiro Co., Ltd. (product name: Timak Mannan). Konjac powder is made by drying and powdering konjac potatoes, but since it is not treated with alkali, most of the glucomannan in konjac powder is water-soluble glucomannan. Indigestible dextrin, polydextrose, isomaltodextrin, guar gum hydrolysate, inulin, β-glucan, chitosan, cellulose, agar, and psyllium seed husk were each obtained from any manufacturer known to those skilled in the art. Guar gum hydrolysate is a linear main chain (β-(1-4)-D-mannopyranose) made of mannose to which galactose (α-D-galactopyranose) is α-(1-6)-bonded, with a weight-average molecular weight of about 20,000. Examples of the production of insoluble glucomannan powder (F1) and mixed water-soluble and insoluble glucomannan powder (G1) are as follows.

[0073] <Example of manufacturing insoluble glucomannan powder (F1)> Insoluble glucomannan powder (F1) was obtained by the following method. First, konjac was ground using a grinder with a grinder of arbitrary clearance, and this ground konjac was dehydrated using a dehydrator. An arbitrary amount of dehydrated grated konjac was dispersed in an arbitrary amount of water to obtain a mixture. The mixture was dried using a dryer. Insoluble glucomannan powder (F1) was obtained by grinding the dried mixture.

[0074] <Example of production of mixed water-soluble and insoluble glucomannan powder (G1)> A mixed glucomannan powder containing both water-soluble and insoluble substances (G1) was obtained by the following method. First, konjac flour (Orihiro Co., Ltd., product name: Timac Mannan (8.5% moisture content, 85.4% dietary fiber content)) was mixed with alkali metals. The mixture was homogenized using a cooking cutter (Hitachi, Ltd., model FV-F3), sealed, left to stand, and then heated to obtain a mixed water-soluble and insoluble glucomannan powder (G1).

[0075] <Example 1> Effect of administering various dietary fibers on promoting the growth of Ackermansia muciniphila Akkermansia muciniphila (ATCC BAA-835) was purchased from ATCC (American Type Culture Collection), and Brain Heart Infusion (BHI) medium was used as the culture medium. The various dietary fibers used in the study were: water-soluble dietary fibers: konjac flour, indigestible dextrin, polydextrose, isomaltodextrin, guar gum hydrolysate, inulin, and β-glucan; insoluble dietary fibers: insoluble glucomannan (indicated as F1 in the figure), chitosan, cellulose, and agar; and mixed dietary fibers: water-soluble and insoluble mixed glucomannan (indicated as G1 in the figure) and psyllium seed husk. Akkermansia muciniphila was cultured for 36 hours in BHI liquid medium to which each dietary fiber was added to a final concentration of 1 mg / ml, and then absorbance was measured. Colony counts were also measured after 36 hours of culture on BHI agar medium. Figure 1 shows the change in turbidity (ΔOD) in the culture medium after 36 hours of incubation. The results showed that all water-soluble dietary fibers had a high growth-promoting effect on Akkermansia muciniphila, and this tendency was particularly pronounced with high-molecular-weight dietary fibers such as konjac flour, guar gum hydrolysate, and β-glucan. Furthermore, among insoluble dietary fibers, insoluble glucomannan derived from konjac (indicated as F1 in the figure) showed a significant growth-promoting effect. A high growth-promoting effect on Akkermansia muciniphila was observed with ) . In addition, among mixed dietary fibers, a high growth-promoting effect on Akkermansia muciniphila was observed with mixed soluble and insoluble glucomannan (indicated as G1 in the figure) and psyllium seed husk. Similar results were obtained when the number of colonies on the agar plate after culture was measured using a method known to those skilled in the art (Figure 2). The above findings indicate that adding dietary fiber is useful in promoting the growth of Akkermansia muciniphila, also known as the "lean bacteria."

Claims

1. A composition for promoting the growth of Akkermansia muciniphila, which contains dietary fiber, The aforementioned dietary fiber, Water-soluble dietary fiber selected from the group consisting of indigestible dextrin and isomaltodextrin; Insoluble glucomannan; or Mixed water-soluble and insoluble glucomannan A growth-promoting composition.

2. The growth-promoting composition according to claim 1, wherein the dietary fiber is a water-soluble dietary fiber selected from the group consisting of indigestible dextrin and isomaltodextrin.

3. The growth-promoting composition according to claim 1, wherein the dietary fiber is insoluble glucomannan.

4. The growth-promoting composition according to claim 1, wherein the dietary fiber is a mixture of water-soluble and insoluble glucomannan.

5. A food composition for promoting the growth of Akkermansia muciniphila, comprising the composition described in any one of claims 1 to 4.

6. A method for promoting the growth of Akkermansia muciniphila, comprising administering the growth-promoting composition described in any one of claims 1 to 4 to Akkermansia muciniphila.

Images