Many stressors, including various diseases, can contribute to the occurrence of dysbiosis in honeybees and potentially perturb gut bacteria (Crotti et al., 2013). Variations of gut microbial communities may be associated with pathogen infection (Cariveau et al., 2014). Interestingly, the gut community was less in larvae infected with EFB and SBV than in non-infected larvae, suggesting a negative interaction between these pathogens and the gut bacteria. These results have a similar discipline with Li et al. (2012) and Cariveau et al. (2014) which reported on the parasite infection research. Some symbiotic bacteria such as Beta (S. alvi) and Gamma-1 (G. apicola) phylotype of A. mellifera also have functions in protection against disease (Martinson et al., 2012). Thus, these symbiotic bacteria in this study maybe participate in the role of virus or bacteria defense which lead to the decline after infection. Potentially, the gut symbionts confer defense or affect immune functioning. Alternatively, environmental stress could perturb the gut community and lead to higher susceptibility of the hosts (Engel and Moran, 2013). However, a causal relationship is not yet confirmed.