Probiotic yeast has been frequently used in animal feed to improve gut microbiota. The gut bacterial community of dairy cattle is very important, because it may influence milk yield and animal health. However, knowledge related to fecal-associated bacterial communities is still very poor. It was hypothesized that feeding probiotic yeast (Yea-Sac ) would improve the microbial population in the gastrointestinal tract of dairy cattle (buffaloes) by analyzing the fecal matter. In this study, the impact of dietary addition of commercially available probiotic yeast (Yea-Sac 1026 ) on the fecal population of some target species related to gut microbes (i.e., Escherichia coli, Enterococcus, Lactococcus, Bacillus, Lactobacillus, Salmonella, Bifidobacterium spp.) was evaluated. For this purpose, six buffaloes were used as experimental animals and two equal groups having three buffaloes (in each) were formed i.e, control feed and experimental probiotic yeast feed group. For two month trial period (60 days), control feed group animals were fed on with routine diet whereas experimental feed group animals were fed on the same diet with addition of commercially available probiotic yeast (Yea-Sac 1026 ) 10g/day/animal. The fecal samples were collected on 1 1026 day. Fecal matter (1gm) was collected individually in disposable bags and used for determining the number of Lactobacillus, Bifidobacterium, E. coli, and Salmonella species. Morphological and biochemical tests of all selected bacterial strains were performed. Results showed that a large bacterial diversity was present in the fecal samples of buffaloes. The relative proportion of beneficial (Lactobacillus, Bifidobacterium) bacteria as well as pathogenic (E.coli and Salmonella species) bacteria were altered by feeding commercially available probiotic yeast (Yea-Sac st , 30 th and 60 th ). So, it is suggested that the commercial probiotic yeast (Yea-Sac 1026 ) can be used to promote the beneficial bacteria in GIT of buffalo to sustain the balance of healthy microbial population and it also helps in reduction of pathogenic bacterial population