To normalize for differences in sequencing depth, the reads will be randomly subsampled at equal number of reads/sample. Data reduction by principal component analysis (PCA) on log2 transformed OTU data and the diversity statistics (Shannon Diversity Index), Bray-Curtis Similarity Index, one-way permutational multivariate analysis of variance (PERMANOVA) and similarity percentage (SIMPER) will be performed using PAST software (17). PCA will be used to visualize the potential microbiome clustering by treatment and by visit. Shannon Diversity index takes into account the number of taxa (OTUs) and the relative contribution of each OTU to the whole dataset. Bray-Curtis Similarity Index is bound between 0 and 1, where 1 means that two samples have the same composition and 0 means the two samples do not share any species. This index will be applied to assess the similarity in microbiomes between the visit 1 (baseline sample) and all other visits from the same individual. This method allows quantifying microbial shift in time. Independent samples T-test will be used to compare the microbiome shifts between the two treatment groups. PERMANOVA will be used to assess if the microbiome profiles differ statistically significantly between the two treatment groups. SIMPER will be used to identify the OTUs that contribute most to the differences between the treatment groups.