AUTHOR=Vasilescu Iulia-Magdalena , Chifiriuc Mariana-Carmen , Pircalabioru Gratiela Gradisteanu , Filip Roxana , Bolocan Alexandra , Lazăr Veronica , Diţu Lia-Mara , Bleotu Coralia 

TITLE=Gut Dysbiosis and Clostridioides difficile Infection in Neonates and Adults

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.651081

DOI=10.3389/fmicb.2021.651081

ISSN=1664-302X

ABSTRACT=<p>In this review, we focus on gut microbiota profiles in infants and adults colonized (CDC) or infected (CDI) with <italic>Clostridioides difficile</italic>. After a short update on CDI epidemiology and pathology, we present the gut dysbiosis profiles associated with CDI in adults and infants, as well as the role of dysbiosis in <italic>C. difficile</italic> spores germination and multiplication. Both molecular and culturomic studies agree on a significant decrease of gut microbiota diversity and resilience in CDI, depletion of <italic>Firmicutes, Bacteroidetes</italic>, and <italic>Actinobacteria</italic> phyla and a high abundance of <italic>Proteobacteria</italic>, associated with low butyrogenic and high lactic acid-bacteria levels. In symptomatic cases, microbiota deviations are associated with high levels of inflammatory markers, such as calprotectin. In infants, colonization with <italic>Bifidobacteria</italic> that trigger a local anti-inflammatory response and abundance of <italic>Ruminococcus</italic>, together with lack of receptors for clostridial toxins and immunological factors (e.g., <italic>C. difficile</italic> toxins neutralizing antibodies) might explain the lack of clinical symptoms. Gut dysbiosis amelioration through administration of “biotics” or non-toxigenic <italic>C. difficile</italic> preparations and fecal microbiota transplantation proved to be very useful for the management of CDI.</p>