Anti-obesity effects of potential probiotic Lactobacillus strains isolated from Mongolian fermented dairy products in high-fat diet-induced obese rodent model.

This study aims to investigate the anti-obesity properties of lactic acid bacteria (LAB) isolated from fermented dairy products such as "Airag" and "Khoormog" in Mongolia. These traditional dairy products are widely used in Mongolia and believe in having potential probiotic, anti-diabetes, anti-cancer, and anti-tuberculosis properties and are made from unheated two-humped camel milk and mare milk, respectively. We chose three LAB strains based on their probiotic characteristics, including tolerance of gastric and bile acids. Then we checked the anti-obesity activity of probiotic strains in vivo. An animal model was evaluated in twenty male C57BL/6J mice by inducing obesity with a high-fat diet (HFD), which was divided into five groups: regular diet group (Negative control), HFD group (Positive control), HFD with Lacticaseibacillus paracasei X-1 (X-1), Lacticaseibacillus paracasei X-17 (X-17), and Limosilactobacillus fermentum BM-325 (BM-325). For six weeks, 5 × 109 colony-forming units (CFU) of bacteria were given orally to the LAB-fed groups. Fasting blood glucose (FBG), lipid profiles, organ index, and organ morphology were all measured. The probiotic strains suppressed growth in adipose cell volume, stabilized FBG, reduced liver cell degeneration, and slowed HFD-induced body weight gain. The results suggest that some strains increase general metabolism while lowering body weight.

Fermented Mare Milk and Its Microorganisms for Human Consumption and Health.

Mare milk is consumed by approximatively 30 million people in the world. In countries in Asia and East Europe, mare milk is mainly consumed as source of fermented products, called koumiss, airag or chigee, alcoholic beverages obtained by means of a culture of bacteria and lactose-fermenting yeasts. Recent research concerning mare milk and its derivatives deals mainly with their potential employment for human health. Studies about the isolation and characterization of Lactobacillus spp. and yeasts from koumiss have been aimed at assessing the potential functional properties of these micro-organisms and to find their employment for the industrial processing of mare milk. The aim of this literature review is to summarize recent research about microorganisms in fermented mare milk products and their potential functional properties.

Comparative study of physicochemical composition and microbial community of Khoormog, Chigee, and Airag, traditionally fermented dairy products from Xilin Gol in China.

Due to their outstanding nutritional and functional properties, the traditionally fermented dairy products (TFDP) from camel, mare, and cow gained universal praise during their long history of production. In this study, the physicochemical composition and microbial communities of Khoormog, Chigee, and Airag, the TFDP from Xilin Gol in China, were investigated and compared. The physicochemical analysis revealed a higher content of total solid content, protein, and fat in Khoormog (12.5 ± 1.6%; 4.6 ± 0.7%; 4.4 ± 1.3%) compared to Chigee (7.8 ± 1.3%; 2.1 ± 0.2%; 0.8 ± 0.2%) and Airag (8.9 ± 0.7%; 3.7 ± 0.4%; 1.4 ± 0.5%). All three types of TFDP shared 41.2% of bacterial and 25.4% of fungal OTUs, and 95.34% of bacterial and 95.52% of fungal sequence reads. The bacterial and fungal community consisted of four phyla and five genera, and three phyla and seven genera, respectively. Lastly, Lactobacillus predominated in Khoormog, Chigee, and Airag at the genus level, while the dominant fungal genera varied among the samples. In conclusion, the microbial community structures of TFDP from camel, mare, and cow were not significantly different in a definite area (Xilingol region), and Khoormog, Chigee, and Airag bred the common "core microbiota".

Biotransformation of Major Ginsenoside Rb1 to Rd by Dekkera anomala YAE-1 from Mongolian Fermented Milk (Airag).

Dekkera anomala YAE-1 strain separated from "airag" (Mongolian fermented mare's milk) produces ß-glucosidase, which can convert ginsenoside Rb1 from Panax ginseng. Ginseng-derived bioactive components such as ginsenoside Rb1 have various immunological and anticancer activities. Airag was collected from five different mare milk farms located near Ulaanbaatar, Mongolia. YAE-1 strains were isolated from airag to examine the hydrolytic activities of ß-glucosidase on Korean Panax ginseng using an API ZYM kit. Supernatants of selected cultures having ß-glucosidase activity were examined for hydrolysis of the major ginsenoside Rb1 at 40°C, pH 5.0. The YAE-1 strain was found to be nearly identical at 99.9% homology with Dekkera anomala DB-7B, and was thus named Dekkera anomala YAE-1. This strain exerted higher ß-glucosidase activity than other enzymes. Reaction mixtures from Dekkera anomala YAE-1 showed great capacity for converting ginsenoside Rb1 to ginsenoside Rd. The ß-glucosidase produced by Dekkera anomala YAE-1 was able to hydrolyze ginsenoside Rb1 and convert it to Rd during fermentation of the ginseng. The amount of ginsenoside Rd was highly increased from 0 to 1.404 mg/ml in fermented 20% ginseng root at 7 days.

Electrical Conductivity, pH, Minerals, and Sensory Evaluation of Airag (Fermented Mare's Milk).

Traditional airag (fermented mare's milk) is a sour, slightly alcoholic drink handmade by Mongolian nomads. As airag is not heated after production, the fermentation continues to proceed and the taste changes rapidly. The objective of this study was to investigate the association of the sensory taste evaluation of airag with some properties-electrical conductivity (EC), pH and concentrations of macro minerals (calcium (Ca), phosphorous (P), sulfur (S), magnesium (Mg), potassium (K), and sodium (Na))-of airag. We held an airag contest in Mogod county, one of the most famous airag production areas, in order to collect samples of airag for the analysis of airag properties and to conduct an airag taste evaluation by Mongolian people. The results of the statistical analysis indicated that the EC-value was related to the evaluation score of airag. Except for EC, no statistically significant relationship between the taste score and the other properties was found in this study. It was concluded that the EC-value would be a simple measurement indicator for evaluating the quality of airag on site.

Movements of dams milked for fermented horse milk production in Mongolia.

Airag, (Fermented horse milk) is a traditional milk product in Mongolia. Herders separate foals from their dams and tie them at a milking site during the daytime to produce airag. To evaluate the effects of horse management on the movement of dams, we tracked three dams in a herd in camp 1 during summer and camp 2 during autumn of 2013 and analyzed their movements during the milking (daytime) and non-milking (nighttime) periods in an area famous for its high-quality airag. Dams were gathered every 1.7 ± 0.0 h between 07.46 and 15.47 hours at the milking sites and milked 4.6 ± 0.2 times/day during the study period (86 days). Daily cumulative and maximum linear distances from the milking sites were longer (P < 0.01) during the non-milking period than during the milking period. Daily home ranges were 91 and 26 times greater during the non-milking period (P < 0.001) in camps 1 and 2, respectively. The greater range during the non-milking period would reflect the spatial distributions of water, salt and forage. The dams initially used similar areas and gradually shifted their daily home ranges after several days. This shift suggests that the dams grazed farther afield as forage availability declined around the milking site. For better airag production and sustainable pasture use, our results provide insights useful for evaluating the effects of milking management on vegetation and soil in those pastures, for selecting the appropriate milking times and frequency, and for choosing the right timing to shift milking sites.

Characterization of airag collected in Ulaanbaatar, Mongolia with emphasis on isolated lactic acid bacteria.

BACKGROUND: Airag, alcoholic sour-tasting beverage, has been traditionally prepared by Mongolian nomads who naturally ferment fresh mares' milk. Biochemical and microbiological compositions of airag samples collected in Ulaanbaatar, Mongolia and physiological characteristics of isolated lactic acid bacteria were investigated. METHODS: Protein composition and biochemical composition were determined using sodium dodecyl sulfate-gel electrophoresis and high performance liquid chromatography, respectively. Lactic acid bacteria were identified based on nucleotide sequence of 16S rRNA gene. Carbohydrate fermentation, acid survival, bile resistance and acid production in skim milk culture were determined. RESULTS: Equine whey proteins were present in airag samples more than caseins. The airag samples contained 0.10-3.36 % lactose, 1.44-2.33 % ethyl alcohol, 1.08-1.62 % lactic acid and 0.12-0.22 % acetic acid. Lactobacillus (L.) helveticus were major lactic acid bacteria consisting of 9 isolates among total 18 isolates of lactic acid bacteria. L. helveticus survived strongly in PBS, pH 3.0 but did not grow in MRS broth containing 0.1 % oxgall. A couple of L. helveticus isolates lowered pH of skim milk culture to less than 4.0 and produced acid up to more than 1.0 %. CONCLUSION: Highly variable biochemical compositions of the airag samples indicated inconsistent quality due to natural fermentation. Airag with low lactose content should be favorable for nutrition, considering that mares' milk with high lactose content has strong laxative effect. The isolates of L. helveticus which produced acid actively in skim milk culture might have a major role in production of airag.

Production of a bacteriocin-like inhibitory substance by Leuconostoc mesenteroides subsp. dextranicum 213M0 isolated from Mongolian fermented mare milk, airag.

Strain 213M0 was selected with productivity of a bacteriocin-like inhibitory substance (BLIS) among 235 strains of lactic acid bacteria (LAB) isolated from Mongolian fermented milk 'airag'. Strain 213M0 was species-identified as Leuconostoc mesenteroides subsp. dextranicum by morphological observation, carbohydrate fermentation profiling and sequencing the 16S rRNA gene. Incubation temperature proper to produce the BLIS was 25°C rather than 30 and 37°C, and the production actively proceeded during the exponential growth phase of the producer cells. Antibacterial effect of BLIS 213M0 was limited to all nine strains of Listeria sp. bacteria and seven strains of LAB cocci among 53 tested strains, which corresponds to a typical feature of the class IIa pediocin-like bacteriocins. BLIS 213M0 was not inactivated in every broad pH range solution (pH 2.0-11.0), and was stable against storage at 25°C for 1 week and heating at 121°C for 15 min under pH 4.5. Peptide frame of BLIS 213M0 was confirmed by inactivation with some peptidases, and then its molecular weight was estimated to be 2.6-3.0 kDa using an in situ activity assay following sodium dodecyl sulfate polyacrylamide gel electrophoresis. The estimated size was different from the other Leuconostoc bacteriocins already reported. These results suggest that BLIS 213M0 would be a novel listericidal bacteriocin.

Distinctive proteolytic activity of cell envelope proteinase of Lactobacillus helveticus isolated from airag, a traditional Mongolian fermented mare's milk.

Airag is a traditional fermented milk of Mongolia that is usually made from raw mare's milk. Lactobacillus helveticus is one of the lactic acid bacteria most frequently isolated from airag. In this study, we investigated the genetic and physiological characteristics of L. helveticus strains isolated from airag and clarified their significance in airag by comparing them with strains from different sources. Six strains of L. helveticus were isolated from five home-made airag samples collected from different regions of Mongolia. The optimal temperature for acidification in skim milk was 30 to 35°C for all the Mongolian strains, which is lower than those for the reference strains (JCM 1554 and JCM 1120(T)) isolated from European cheeses. All of the strains had a prtH1-like gene encoding a variant type of cell envelope proteinase (CEP). The CEP amino acid sequence in Snow Brand Typeculture (SBT) 11087 isolated from airag shared 71% identity with PrtH of L. helveticus CNRZ32 (AAD50643.1) but 98% identity with PrtH of Lactobacillus kefiranofaciens ZW3 (AEG40278.1) isolated from a traditional fermented milk in Tibet. The proteolytic activities of the CEP from SBT11087 on artificial substrate (N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide) and pure casein were measured using an intact-cell degradation assay. The activity of the CEP from SBT11087 was observed to be weak and exhibited a lower optimal temperature (40°C) than those from the reference strains (45-50°C). The specificity of the SBT11087 CEP for αS1-casein was typical of the CEPs previously reported in L. helveticus, as determined through the degradation profiles obtained through gel electrophoresis and mass spectrometry analyses. In contrast, the degradation profile of ß-casein revealed that the CEP of SBT11087 primarily hydrolyzes its C-terminal domain and hydrolyzed nine of the 16 cleavage sites shared among the CEPs of other L. helveticus strains. Thus, the CEP of SBT11087 is distinct from those from previously reported L. helveticus strains in terms of its optimal temperature and its degradation of ß-casein. Therefore, the Mongolian L. helveticus strains differ from other strains of the species in different collections and are specifically suited for the natural lactic acid bacterial population in airag.

Pyrosequencing analysis of the microbial diversity of airag, khoormog and tarag, traditional fermented dairy products of mongolia.

Here, we used pyrosequencing to obtain a detailed analysis of the microbial diversities of traditional fermented dairy products of Mongolia. From 22 Airag (fermented mare's milk), 5 Khoormog (fermented camel's milk) and 26 Tarag (fermented milk of cows, goats and yaks) samples collected in the Mongolian provinces of Arhangai, Bulgan, Dundgobi, Tov, Uburhangai and Umnugobi, we obtained a total of 81 operational taxonomic units, which were assigned to 15 families, 21 genera and 41 species in 3 phyla. The genus Lactobacillus is a core bacterial component of Mongolian fermented milks, and Lactobacillus helveticus, Lactobacillus kefiranofaciens and Lactobacillus delbrueckii were the predominant species of lactic acid bacteria (LAB) in the Airag, Khoormog and Tarag samples, respectively. By using this pyrosequencing approach, we successfully detected most LAB species that have been isolated as well as seven LAB species that have not been found in our previous culture-based study. A subsequent analysis of the principal components of the samples revealed that L. delbrueckii, L. helveticus, L. kefiranofaciens and Streptococcus thermophilus were the main factors influencing the microbial diversity of these Mongolian traditional fermented dairy products and that this diversity correlated with the animal species from which the milk was sourced.