Background: The intestinal microbiota of Mongolians and its composition is of great interest of researchers, a few studies have did in this fields. Maybe Mongolian encompass a uniquely wide range of environmental conditions, ethno geographical cohorts and traditional nomadic lifestyles. Goal: We aimed to determine the amount of gut microbiota, including Lactobacillus and Bifidobacterium in the fecal samples of relative healthy Mongolian adults residing in various regions of Mongolia by conventional culture method and PCR. Material and Methods: The study was performed population based cross sectional study in healthy volunteers. In this study, 256 relative healthy Mongolian adults with no history of gastrointestinal associated diseases were enrolled between July 2018 and April 2019. Each participants was asked to complete a questionnaire containing 164 questions about demographics, physical activity, dietary habits. Fecal samples were collected for Lactobacillus and Bifidobacterium analysis using culture method and determination of genus of Bifidobacterium sрp and Lactobacillus spp by PCR. ResultsParticipants had a mean age of 38.9±12.8 years. The mean values of Lactobacillus by culture method were 5.9±1.28 and 6.24±0.94 log10 CFU/ml (4.67х106 , 4.66х106 CFU/ml), respectively. The abundance of Lactobacillus had a positive correlation with grams for fiber and amount of bifidobacterium ((r= 0.495, р<0.001, r=0.288, p<0.05), respectively). Significant difference were observed between groups of milk frequency per day for amounts of lactobacillus. In adult intestinal tracts, B.Bifidum was the most common taxon 31 (29%) followed by B. angulatum 14 (13.1%), B. adolescentis 10 (9.3%), B. catenulatum group 10 (9.3%), B. longum 9 (8.4%). B. lactis, B. breve, B. dentium and B. gallicum were subdominant species. Conclusion: The mean amount of Bifidobacterium and Lactobacillus of all participants were 6.24±0.94 and 5.9±1.28 log10 CFU/ml (4.66*106 , 4.67*106 CFU/ml) respectively. The Lactobacillus abundance of healthy adults was higher in region of Khangai, East and West of Mongolian than other regions. The composition of lactobacillus altered with ageing. Significant correlations were found between fiber, fats, potato and amount of Lactobacillus. Keywords: Bifidobacterium, Colony forming unit, Gut microbiota, Lactobacillus

BACKGROUND Bovine colostrums is the milk secreted by cows during the first few days after parturition. It contains many essential nutrients and bioactive components, including growth factors, immunoglobulins, lactoperoxidase, lactoferrin and cytokines ets. Lactoferrin has been reported for its multifunctional properties such as antifungal, antibacterial, antiviral antioxidant and anticancer activities. The aims of this study focused on the isolation and purification of lactoferrin from Mongolian bovine colostrums. Lactoferrin purified using HiTrap DEAE an ion exchange chromatography. Lactoferrin purification efficiency was about 60.5%. The single band of purified lactoferrin has been observed in SDS-PAGE electrophoresis. METHODS Bovine colostrum was collected at a cow farm in the Darkhan province of Mongolia. At first the cream was separated by centrifugation (10000 xg 20 min at 4oC). In order to separate the whey, the samples were precipitated with 1mol/l to pH 4.6 and centrifuged at 10000 g 20 min again. The samples of whey were stored at -18oC to the analysis. Lactoferrin was purified by HiTrap DEAE an ion exchange chromatography using 0.005 M phosphate buffer (pH 7.7) and linear gradient NaCl from 0.25M, 0.5M, 1M. During chromatography, protein in the eluents was monitored by ultraviolet absorbation at 280 nm with the instrument. Purity test done by using polyacrylamide gel electrophoresis under denaturated condition (SDS-PAGE) method by Laemmli (1970). For HPLC determination of the lactoferrin by Shimadzu Nexera X2 HPLC system with UV/ VIS detector were used. Detection was carried out at the wavelength 280 nm. Separation was performed on a chromatographic column Protein R C18 ,2.2 x 150 mm, 5 μm particle size. Linear gradient and flow rate 0.2 ml/min were used. Mobile phase a consisted of water / acetonitrile/ trifluoroacetic acid ( 95:5:0.1). The column temperature was set at 40oC and injection volume was 10 μl. Data were collected and evaluated by software Lab Solution. An external standard method for quantification analytes was used. RESULTS Purified lactoferrin in the present study had a good concentration and purification efficiency was about 60.5 %. Protein fraction from 1M NaCl gradient delivers sharp and clean peak to HPLC chromatogram that fits intensity and retention time of standard bovine lactoferrin. Ammount of lactoferrin in bovine colostrums was 0.6 mg/ml and it`s molecular weight 80 kDa as a standard sample. The retention time of lactoferrin fraction which is purified by SDS-PAGE gel electrophoresis. The peak of fraction same compared to the standard lactoferrin 5.8 minutes by HPLC analysis. CONCLUSION Ion exchange chromatography shows reliable and easy isolation of lactoferrin from Mongol bovine colostrum.