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