Gut dysbiosis is a fundamental factor for various human diseases such as obesity, non-alcoholic fatty liver disease, diabetes mellitus, and even cancers. Tremendous publications on the relationship between gut microbiota and diseases are available during the past years in the context of advances of 16S rDNA-based bacteria sequencing technology. Notably, data of gut microbiome usually showed dramatic variation and poor consistency between different reports. Unfortunately, most scientists paid little attention to the authenticity of the 16S rDNA sequencing data provided by the third party. Actually, there are various ways for introducing disturbance on the variation and consistency of results during the whole process from sample collection to analysis. In this speech, I will take the obesity study for example to discuss the variation and inconsistency of previous publications, and provide some of our recent observations on the data consistency when different storages were used based on the 16S rDNA sequencing technology. Thus, we highlight the importance of re-evaluating the consistency and variation of the data in gut microbiome.