**2. Sources and general properties of β-glucans**

β-glucans are long-chain, multidimensional polymers of glucose, in which particular particles of glucopyranose are linked with glycosidic bonds of β type, linearly, in (1→3) and/or (1→4) structure or in a branched way, i.e. with side chains of varied length, linked to the main core with glycosidic bonds of β-(1→6) type. They are structural components of plant cell walls (mostly cereals – oats and barley), yeast (*Saccharomyces cerevisiae, Saccharomyces fragilis, Candida tropicalis, Candida utilis* among others), as well as the socalled Chinese or Japanese fungi. Also beta glucans constituting the components of cell walls, or being the excretion of various bacteria (e.g. *Alcaligenes faecalis* var*. Myxogenes, Cellulomonas flavigena Bacillus* or *Micromonospora)* [4] are known. The presence of β-glucans have also been confirmed in the cell walls of some vegetables (carrot, radish, soybean) and fruit (bananas) [5].

Spent Brewer's Yeast and Beta-Glucans Isolated from Them as Diet Components

polymerisation (DP) is higher than 100 [6]. Insoluble or slightly soluble beta glucans contain

Molecular weight of beta glucans obtained from various sources differs within a wide range of values from 0,2 x 101 kDa to 4 x 104 kDa. From technological point of view, beta glucans of high molecular weight (> 3 x 103 kDa) are characterised by high viscosity, and those of low molecular weight (about 9 kDa) constitute gels. Hydrolysed beta-glucans are soluble, but

Physicochemical properties of β-glucans might be modified through the use of various technologies during their isolation. Used chemical or enzymatic methods, leading to the hydrolysis of long-chain β-glucans, allow to lower the degree of depolymerisation and their particle mass in relation to native form, which simultaneously increases their solubility and

Among many methods leading to depolymerisation of long-chained and multi-branched βglucans, it is essential to distinguish other chemical modifications, e.g. esterification [8], phosphorylation [9], sulphonation [10], chlorosulphonation [11], or carboxylmethylation [12]. This last method is considered to be one of the most effective methods transforming insoluble forms into soluble fractions [13]. All authors state, however, that introducing an additional functional group to β-glucan chain might lead to simultaneous growth of glucan particle size, which in turn leads to excessive increase in their viscosity in water solution, and therefore, shows different than expected physiological influence [14]. There is also research published showing that viscosity of β-gluccans depends to a large extent on the

very long, multi-branched side chains in the particle (Fig. 2).

**Figure 1.** An example of the molecular structure of soluble yeast β-glucan.

not very viscous and do not constitute gels.

degree of purification during their isolation [15].

lowers viscosity in liquids [7].

Modifying Blood Lipid Metabolism Disturbed by an Atherogenic Diet 263

β-glucans isolated from fungi seem to be the most advantageous, i.e. of greatest pro-health influence. β-glucans from cereals are quite well-known. Present interest in isolating βglucans takes into account new sources of β-glucans, e.g. baker's yeast *Sacharomyces cerevisiae*, considered a better source than cereals or fungi in terms of economics.

The pro-health influence of beta glucans on the body depends on their physicochemical properties. The physicochemical properties of *β*-glucans differ depending on characteristics of their primary structure, including linkage type, degree of branching, molecular weight, and conformation (e.g. triple helix, single helix, and random coil structures) [3,4].

Native β-glucans, depending on their origin contain different bonds, show varied solubility degree and varied direction of pro-health influence. Beta glucans from:


A lower level of branching and lower polymerisation degree are characterised by better solubility (Fig. 1). It is believed that insoluble β-glucans are those whose degree of polymerisation (DP) is higher than 100 [6]. Insoluble or slightly soluble beta glucans contain very long, multi-branched side chains in the particle (Fig. 2).

**Figure 1.** An example of the molecular structure of soluble yeast β-glucan.

262 Lipid Metabolism

fruit (bananas) [5].

inflammatory.

mostly (13)-(16)-β forms.

**2. Sources and general properties of β-glucans** 

β-glucans are long-chain, multidimensional polymers of glucose, in which particular particles of glucopyranose are linked with glycosidic bonds of β type, linearly, in (1→3) and/or (1→4) structure or in a branched way, i.e. with side chains of varied length, linked to the main core with glycosidic bonds of β-(1→6) type. They are structural components of plant cell walls (mostly cereals – oats and barley), yeast (*Saccharomyces cerevisiae, Saccharomyces fragilis, Candida tropicalis, Candida utilis* among others), as well as the socalled Chinese or Japanese fungi. Also beta glucans constituting the components of cell walls, or being the excretion of various bacteria (e.g. *Alcaligenes faecalis* var*. Myxogenes, Cellulomonas flavigena Bacillus* or *Micromonospora)* [4] are known. The presence of β-glucans have also been confirmed in the cell walls of some vegetables (carrot, radish, soybean) and

β-glucans isolated from fungi seem to be the most advantageous, i.e. of greatest pro-health influence. β-glucans from cereals are quite well-known. Present interest in isolating βglucans takes into account new sources of β-glucans, e.g. baker's yeast *Sacharomyces* 

The pro-health influence of beta glucans on the body depends on their physicochemical properties. The physicochemical properties of *β*-glucans differ depending on characteristics of their primary structure, including linkage type, degree of branching, molecular weight,

Native β-glucans, depending on their origin contain different bonds, show varied solubility




A lower level of branching and lower polymerisation degree are characterised by better solubility (Fig. 1). It is believed that insoluble β-glucans are those whose degree of

*cerevisiae*, considered a better source than cereals or fungi in terms of economics.

and conformation (e.g. triple helix, single helix, and random coil structures) [3,4].

degree and varied direction of pro-health influence. Beta glucans from:

concentration and triacyloglycerols in blood,

Molecular weight of beta glucans obtained from various sources differs within a wide range of values from 0,2 x 101 kDa to 4 x 104 kDa. From technological point of view, beta glucans of high molecular weight (> 3 x 103 kDa) are characterised by high viscosity, and those of low molecular weight (about 9 kDa) constitute gels. Hydrolysed beta-glucans are soluble, but not very viscous and do not constitute gels.

Physicochemical properties of β-glucans might be modified through the use of various technologies during their isolation. Used chemical or enzymatic methods, leading to the hydrolysis of long-chain β-glucans, allow to lower the degree of depolymerisation and their particle mass in relation to native form, which simultaneously increases their solubility and lowers viscosity in liquids [7].

Among many methods leading to depolymerisation of long-chained and multi-branched βglucans, it is essential to distinguish other chemical modifications, e.g. esterification [8], phosphorylation [9], sulphonation [10], chlorosulphonation [11], or carboxylmethylation [12]. This last method is considered to be one of the most effective methods transforming insoluble forms into soluble fractions [13]. All authors state, however, that introducing an additional functional group to β-glucan chain might lead to simultaneous growth of glucan particle size, which in turn leads to excessive increase in their viscosity in water solution, and therefore, shows different than expected physiological influence [14]. There is also research published showing that viscosity of β-gluccans depends to a large extent on the degree of purification during their isolation [15].

Spent Brewer's Yeast and Beta-Glucans Isolated from Them as Diet Components

Slightly different properties are characteristic of β-glucans isolated from sorghum, in which all three types of chains, i.e. both β-(1→3)-, β-(1→ 4)-, and β-(1→ 6) [17] have been found. In β-glucans isolated from most cereals β-(1→3) bonds constitute about 30%, whilst β-(1→4) bonds - about 70% of all bonds, with slight deviations characteristic of particular cereals [18]. β-glucans from oat are known as substances of pro-health influence comparable to βglucans isolated from barley [19], particularly in the ability to lower glucose concentration in

β-glucans extracted from cereals, which mainly contain β-(1,3-1,4)-d-glucan, have been demonstrated to reduce blood lipid levels, including cholesterol and triacylglycerols levels. The mechanisms by which β-glucans from cereals reduce blood lipid levels have been shown to include prevention of cholesterol reabsorption by adsorption, elimination of bile acid by adsorption, an increase in bile acid synthesis, and suppression of hepatic cholesterol biosynthesis by short-chain fatty acids produced by fermentation with intestinal bacteria

There are "medicinal" fungi, used in traditional medicine of the countries of the East [25], such as Chinese Reishi (*Ganoderma lucidum),* or Japanese Shiitake *(Lentinula edodes)* and Maitake (*Grifola frondosa*), arboreal fungi: Chaga (*Inonotus obliquus),* Turkey Tail (*Trametes versicolor),* Split Gill (*Schizophyllum commune),* Mulberry Yellow Polypore (*Phellinus linteus)*  and cultivated, e.g. Hiratake (*Pleurotus ostreatus, Oyster mushroom*). The concentration of βglucans in Basidiomycota fungi is relatively low and ranges from 0.21 to 0.53 g/100 g of dry

O

*(1-6)-*

O

O O

CH2

OH

HO

OH

n

CH2

O

OH

O

OH

OH

CH2

O

OH

HO

CH2

O O

OH

*(1-3)-*

HO

OH

β-glucans isolated from fungi are heteroglucans containing both (13)/(14)-β and (13)/(16)-β bonds. They usually constitute the mixture of insoluble (about 53-83%

OH

blood [20], total cholesterol and triacylglycerols in blood [21,22].

[23,24].

mass [26].

**2.2. β-glucans isolated from fungi** 

O

O

O

CH2

O

OH

OH

O

OH

OH

HO

CH2

OH

**Figure 4.** Primary molecular structure of lentinan from *Lentinus edodes*.

CH2

OH

HO

O

OH

Modifying Blood Lipid Metabolism Disturbed by an Atherogenic Diet 265

**Figure 2.** An example of the molecular structure of insoluble yeast β-glucan.

#### **2.1. β-glucans isolated from cereals**

Among cereals, the greatest amount of β-glucan in relations to dry mass can be found in barley grains (3-11%) and oat grains (3-7%). Small quantities of β-glucans are also found in rice (about 2%), wheat (about 1%) and sorghum (0.2-0.5%) [11]. In case of oat, β-glucans are present mostly in external layers of the grain, whilst in barley grain, these substances are spread evenly in the entire grain.

Unlike insoluble cellulose, whose glucose particles are linked linearly with -D-(1→4) bonds, β-glucans contained in the endosperm of cereals grains are the mixture of -Dglucose unbranched chains linked with -(1→3) and -(1→4) glycosidic bonds (Fig. 3) [16].

**Figure 3.** Primary molecular structure of (1-3)/(1-4)-β-glucan from barley grain.

Slightly different properties are characteristic of β-glucans isolated from sorghum, in which all three types of chains, i.e. both β-(1→3)-, β-(1→ 4)-, and β-(1→ 6) [17] have been found. In β-glucans isolated from most cereals β-(1→3) bonds constitute about 30%, whilst β-(1→4) bonds - about 70% of all bonds, with slight deviations characteristic of particular cereals [18].

β-glucans from oat are known as substances of pro-health influence comparable to βglucans isolated from barley [19], particularly in the ability to lower glucose concentration in blood [20], total cholesterol and triacylglycerols in blood [21,22].

β-glucans extracted from cereals, which mainly contain β-(1,3-1,4)-d-glucan, have been demonstrated to reduce blood lipid levels, including cholesterol and triacylglycerols levels. The mechanisms by which β-glucans from cereals reduce blood lipid levels have been shown to include prevention of cholesterol reabsorption by adsorption, elimination of bile acid by adsorption, an increase in bile acid synthesis, and suppression of hepatic cholesterol biosynthesis by short-chain fatty acids produced by fermentation with intestinal bacteria [23,24].

#### **2.2. β-glucans isolated from fungi**

264 Lipid Metabolism

**Figure 2.** An example of the molecular structure of insoluble yeast β-glucan.

O

6 1

<sup>O</sup> <sup>O</sup>

1

**Figure 3.** Primary molecular structure of (1-3)/(1-4)-β-glucan from barley grain.

O

2

HOH2C

3

4 <sup>5</sup>

1 n

2

Among cereals, the greatest amount of β-glucan in relations to dry mass can be found in barley grains (3-11%) and oat grains (3-7%). Small quantities of β-glucans are also found in rice (about 2%), wheat (about 1%) and sorghum (0.2-0.5%) [11]. In case of oat, β-glucans are present mostly in external layers of the grain, whilst in barley grain, these substances are

Unlike insoluble cellulose, whose glucose particles are linked linearly with -D-(1→4) bonds, β-glucans contained in the endosperm of cereals grains are the mixture of -Dglucose unbranched chains linked with -(1→3) and -(1→4) glycosidic bonds (Fig. 3) [16].

O

O

O

<sup>1</sup> <sup>2</sup>

O

O

HOH2C

5 6

4

<sup>6</sup> <sup>1</sup> <sup>2</sup> 3

HOH2C

**2.1. β-glucans isolated from cereals** 

O

4

2

4 5

HOH2C

3

spread evenly in the entire grain.

O

HOH2C

6

5

3

There are "medicinal" fungi, used in traditional medicine of the countries of the East [25], such as Chinese Reishi (*Ganoderma lucidum),* or Japanese Shiitake *(Lentinula edodes)* and Maitake (*Grifola frondosa*), arboreal fungi: Chaga (*Inonotus obliquus),* Turkey Tail (*Trametes versicolor),* Split Gill (*Schizophyllum commune),* Mulberry Yellow Polypore (*Phellinus linteus)*  and cultivated, e.g. Hiratake (*Pleurotus ostreatus, Oyster mushroom*). The concentration of βglucans in Basidiomycota fungi is relatively low and ranges from 0.21 to 0.53 g/100 g of dry mass [26].

**Figure 4.** Primary molecular structure of lentinan from *Lentinus edodes*.

β-glucans isolated from fungi are heteroglucans containing both (13)/(14)-β and (13)/(16)-β bonds. They usually constitute the mixture of insoluble (about 53-83% participation) and soluble (about 16-46%) fractions [40] of varied properties. They are mostly known as factors stimulating the immune system, having antiviral, antimicrobial and antiallergic properties [27,28]. They also have the ability to lower high blood pressure, slow down the excessive cholesterol synthesis and lower glucose concentration in blood [29], as well as show antioxidating properties [23]. They are also known as substances of antitumour properties [4]. β-glucans well-known in terms of structure and biological activity are identified in accordance with their names, e.g.: lentinan (Fig. 4) obtained from *Lentinus edodes*, schizophyllan (SPG) (Fig. 5A) from *Schizophyllum commune*, pleuran from *Pleurotus* o*streatus or* pullulans (AP-FBG) (Fig. 5B) from *Aureobasidium pullulans,* scleroglucan (SGG) (Fig. 6) from S*clerotium* rolfsii, grifolan (GRN) from *Grifola frondosa*, krestin (PSK polysaccharide-K and PSP - polysaccharopeptide) from *Coriolus versicolor* [30-34].

Spent Brewer's Yeast and Beta-Glucans Isolated from Them as Diet Components

Polysaccharides of bacterial origin are known and widely used in food industry mostly as additives. They are often called bacterial egzopolisaccharides and constitute the ingredient of the cell wall, or can be excretions of various microorganisms, such as: *Cellulomonas flavigena* of KU strain [36], *Bacillus curdlanolyticus* and *Bacillus kobensis* [37], *Bacillus* and *Micromonospora* [38] *Agrobacterium* spp. ATCC31749 [39], *Bradyrhizobium, Rhizobium* spp.

The ones mass produced and used are: xanthan, dextran, pullulan or gellan. β-glucans of bacterial origin have the structure similar to mannans, but glucose constitutes their basic unit building block. Mucilages called xanthans produced by *Xanthomonas campestris* bacteria pathogenic for plants are widely used*.* Beta glucans produced as a result of microbiological fermentation called curdlan (Fig. 7) and laminarin are known from technological point of

**Figure 7.** Primary molecular structure of (1-3)-β-glukan (A – curdlan; B - laminarin).

**2.4. β-glucans isolated from Saccharomyces cerevisiae** 

containing glucose particles connected most often with (1→6) bonds of α type [41].

Dextran is a glucan synthesized from saccharose by *Leuconostoc mesenteroides* and *Streptococcus*,

Microorganisms used in food industry, mostly lactid acid bacteria (LAB) are a rich source of

Yeast, both baker's and spent brewer's yeast, are characterised by high concentration of beta glucans, amounting on average to 7.7%, located in the cell wall. Cell wall (constituting 15- 30% of dry mass of yeast cells), is a complex, multi-particle structure, consisting in 50-60% of β-glucans and in about 40% of mannoproteins. Natural β-glucans isolated from yeast are insoluble in water, and their insolubility is caused by chitin, a polisaccharid consisting of residues of N-acetyl-glucosamine, linked with (1→4)-β-glycosidic bonds (chitin amounts to about 1% of cell wall mass). Chitin complex–(1→3)-β-glucan (about 3-9% of cell wall mass), is located on the inside of cell wall (1→6)-β β-glucan branches, link particular components of cell wall with the use of mannoproteins and covalent bonds. Mannoproteins are located on

**2.3. β-glucans isolated from bacteria** 

*Sarcina ventriculi* [40].

egzopolisaccharides [42].

the outside of yeast cell wall [43].

view.

Modifying Blood Lipid Metabolism Disturbed by an Atherogenic Diet 267

**Figure 5.** Primary molecular structure of Schizophyllan (A) from *Schizophyllum commune* and pleuran (B) from *Aureobasidium pullulans.*

**Figure 6.** Primary molecular structure of scleroglucan from S*clerotium rolfsii.*

Recently characterized structure of a novel water-soluble polysaccharide (ZPS - Zhuling polysaccharide) from the fruit bodies of medicinal mushroom *Polyporus umbellatus* and investigate its immunobiological function [35].

#### **2.3. β-glucans isolated from bacteria**

266 Lipid Metabolism

(B) from *Aureobasidium pullulans.*

participation) and soluble (about 16-46%) fractions [40] of varied properties. They are mostly known as factors stimulating the immune system, having antiviral, antimicrobial and antiallergic properties [27,28]. They also have the ability to lower high blood pressure, slow down the excessive cholesterol synthesis and lower glucose concentration in blood [29], as well as show antioxidating properties [23]. They are also known as substances of antitumour properties [4]. β-glucans well-known in terms of structure and biological activity are identified in accordance with their names, e.g.: lentinan (Fig. 4) obtained from *Lentinus edodes*, schizophyllan (SPG) (Fig. 5A) from *Schizophyllum commune*, pleuran from *Pleurotus* o*streatus or* pullulans (AP-FBG) (Fig. 5B) from *Aureobasidium pullulans,* scleroglucan (SGG) (Fig. 6) from S*clerotium* rolfsii, grifolan (GRN) from *Grifola frondosa*, krestin (PSK -

polysaccharide-K and PSP - polysaccharopeptide) from *Coriolus versicolor* [30-34].

**Figure 5.** Primary molecular structure of Schizophyllan (A) from *Schizophyllum commune* and pleuran

6

CH2 OH

OH

3

O

O

2 1

OH

O

OH

n

CH2OH

3

OH

4 5

O O O O

Recently characterized structure of a novel water-soluble polysaccharide (ZPS - Zhuling polysaccharide) from the fruit bodies of medicinal mushroom *Polyporus umbellatus* and

OH

4 4

1

5 5

OH

1 1 2 2

3

CH2

O

O

1

OH

**Figure 6.** Primary molecular structure of scleroglucan from S*clerotium rolfsii.*

OH

6

6 6

OH

CH2 OH

5 4

investigate its immunobiological function [35].

3 2

Polysaccharides of bacterial origin are known and widely used in food industry mostly as additives. They are often called bacterial egzopolisaccharides and constitute the ingredient of the cell wall, or can be excretions of various microorganisms, such as: *Cellulomonas flavigena* of KU strain [36], *Bacillus curdlanolyticus* and *Bacillus kobensis* [37], *Bacillus* and *Micromonospora* [38] *Agrobacterium* spp. ATCC31749 [39], *Bradyrhizobium, Rhizobium* spp. *Sarcina ventriculi* [40].

The ones mass produced and used are: xanthan, dextran, pullulan or gellan. β-glucans of bacterial origin have the structure similar to mannans, but glucose constitutes their basic unit building block. Mucilages called xanthans produced by *Xanthomonas campestris* bacteria pathogenic for plants are widely used*.* Beta glucans produced as a result of microbiological fermentation called curdlan (Fig. 7) and laminarin are known from technological point of view.

**Figure 7.** Primary molecular structure of (1-3)-β-glukan (A – curdlan; B - laminarin).

Dextran is a glucan synthesized from saccharose by *Leuconostoc mesenteroides* and *Streptococcus*, containing glucose particles connected most often with (1→6) bonds of α type [41].

Microorganisms used in food industry, mostly lactid acid bacteria (LAB) are a rich source of egzopolisaccharides [42].

#### **2.4. β-glucans isolated from Saccharomyces cerevisiae**

Yeast, both baker's and spent brewer's yeast, are characterised by high concentration of beta glucans, amounting on average to 7.7%, located in the cell wall. Cell wall (constituting 15- 30% of dry mass of yeast cells), is a complex, multi-particle structure, consisting in 50-60% of β-glucans and in about 40% of mannoproteins. Natural β-glucans isolated from yeast are insoluble in water, and their insolubility is caused by chitin, a polisaccharid consisting of residues of N-acetyl-glucosamine, linked with (1→4)-β-glycosidic bonds (chitin amounts to about 1% of cell wall mass). Chitin complex–(1→3)-β-glucan (about 3-9% of cell wall mass), is located on the inside of cell wall (1→6)-β β-glucan branches, link particular components of cell wall with the use of mannoproteins and covalent bonds. Mannoproteins are located on the outside of yeast cell wall [43].

Sparse research on β-glucans isolated in the laboratory from cell walls of baker's yeast *Saccharomyces cerevisiae,* shows varied biological activity depending on the used technology of their isolation. They can strengthen the immune system, show antioxidant properties, and delay the process of cell aging [23,44].

Spent Brewer's Yeast and Beta-Glucans Isolated from Them as Diet Components

Functional properties, i.e. physico-chemical properties of dried spent brewer's yeast and βglucans isolated from them have been characterized. In order to determine the influence of glucan preparations (soluble BG-CMG and native - insoluble BG-HP) and spent brewer's yeast on the lipid metabolism of the rat body, examined preparations have been added to atherogenic diet of animals (1% of cholesterol and 20% of fat) in such an amount so as to

a. for β-glucans: 10 and 100 mg/kg of body mass - the dose of 10 mg/kg body mass is the amount calculated for an adult weighing 70 kg - 700 mg per day, the dose 100 mg/kg

b. Spent brewer's yeast were added in the amount 100 mg daily (0.5% of diet components, which is about 500 mg/kg body weight). This amount corresponded to the intake of

The research has been conducted in relation to control group, which has not been given




The experimental animals were growing male rats (Wistar) with an initial body weight of about 100 g. Prior to the start of the experiment, animals were given water and commercial, standard rat food LSM® ad libitum for 7 days to adapt them to the experimental conditions. Later the animals were randomly divided into 6 groups (7 rats in one group) in relation with

beta-glucans from spent brewer's yeast in an amount of 10 mg/kg body weight.

**4. Research material and conditions of biological experiment** 


walls): insoluble BG-HP (Beta HP(1/3)-(1/6)-β-D-Glucane Powder),

German company LEIBER GmbH - INTER YEAST.

**4.1. Biological experiment and its progress** 

obtain the following levels:

yeast preparation additive.

Material consisted of:

diet composition:

a. Control - without β-glucans,

b. BG-CMG - with carboxymethylglucan: BG-CMG10 (10 mg/kg of body mass), BG-CMG100, (100 mg/kg of body mass),

c. BG-HP - with insoluble beta glucan: BG-HP10 (10 mg/kg of body mass), BG-HP100 (100 mg/kg of body mass), d. and SBY – with dried spent brewer's yeast.

body mass – 7 g per day,

Modifying Blood Lipid Metabolism Disturbed by an Atherogenic Diet 269

Due to a high content of β-glucans in spent brewer's yeast *Saccharomyces cerevisiae*, remaining after alcohol fermentation in the process of beer production, it seems that they can be an effective and inexpensive material for obtaining β-glucan preparations.

Fig. 8 presents the diagram showing the use of spent brewer's yeast, which constitute troublesome waste for the brewing industry.

**Figure 8.** The possibilities of using spent brewer's yeast *Saccharomyces cerevisiae*.

Beta glucans might be obtained as a byproduct in the production of preparations enhancing flavour (yeast extracts), and the remains after fibre extraction constitute a good material for obtaining beta glucans.

So far no research has been conducted on pro-health β-glucans obtained from spent brewer's yeast *Saccharomyces cerevisiae*, which constitute a natural, often a troublesome byproduct of the brewing industry, waste product after alcohol fermentation in beer production. Sparse research on β-glucans obtained from this type of material is conducted on a laboratory scale and aims mostly to examine their technological properties, conditioning their usage as additional substances of thickening, gelling and/or water binding properties.

#### **3. The purpose and scope of work**

This work has aimed to assess pro-health activity of β-glucans isolated from a new, uninvestigated within this scope source, i.e. spent brewer's yeast *Saccharomyces cerevisiae*. Functional properties, i.e. physico-chemical properties of dried spent brewer's yeast and βglucans isolated from them have been characterized. In order to determine the influence of glucan preparations (soluble BG-CMG and native - insoluble BG-HP) and spent brewer's yeast on the lipid metabolism of the rat body, examined preparations have been added to atherogenic diet of animals (1% of cholesterol and 20% of fat) in such an amount so as to obtain the following levels:


The research has been conducted in relation to control group, which has not been given yeast preparation additive.
