Analysis of Fecal Microbiota Diversity in Hospitalized Elderly Patients with Antibiotic- associated Diarrhea

Abstract

Abstract Background: Although a lot of research has confirmed that antibiotics caused microbiota disturbance, the correlation between microbiota and antibiotic treatments in hospitalized elderly patients has not been well studied. Antibiotic-associated diarrhea (AAD) is a common and important ailment in elderly patients, and therefore there is a need for clues to guide antibiotic usage in hospitalized elderly patients. Methods: Thirty-eight elderly patients who were admitted to a medium-sized ward in Huashan hospital affiliated to Fudan University, were divided into various subgroups according to the length of hospitalization and occurrence of AAD. For the identification of microbes, microbial genomic DNA was extracted from fecal samples and subjected to 16S rDNA amplicon pyrosequencing followed by microbial analysis. Results: The antibiotic regimen significantly altered the composition of fecal microbiota, irrespective of the length of hospitalization. In general, lower microbial alpha-diversity, involving decreased abundance of Bifidobacteriumand increased abundance of Enterococcus, was found in all antibiotic-treated patients. Interestingly, the composition of microbiota was significantly different between patients with or without AAD even under similar antibiotic regimens. The supplementation of probiotics benefited AAD patients by protecting against Enterococcus colonization. Conclusions: The fecal microbiota of hospitalized elderly patients was significantly affected by antibiotic usage. Under similar antibiotic regimens, altered microbiota composition was closely related to the occurrence of AAD. The results revealed the importance of microbiota analysis and appropriate interventions during intensive antibiotic usage among hospitalized elderly patients.