Figure 1.

Summary of differences found at key body sites in studies of Chronic Kidney Disease (CKD) patients and kidney transplant recipients post-operation discussed in this review. For CKD patients, health changes associated with microbiome alteration include: (Oral) increased urea and pH (Lasisi et al., 2016), plaque, enamel defects, gingival enlargement and decreased caries (Al Nowaiser et al., 2003), (Kidney) declining function and build-up of toxins (Pandya et al., 2016), and (Gut) gut dysfunction and disruption of epithelial tight junction (Vaziri et al., 2013b). Reported microbial change includes significant changes in oral and gut communities compared with healthy controls (Hu et al., 2018; Hobby et al., 2019). For kidney transplant recipients, post-transplant health changes associated with microbiome alteration include: (Oral) increased mucosal lesions, gingival hyperplasia, risk of extra-oral colonization, and squamous cell carcinoma (Spolidorio et al., 2006), (Kidney) variations in time taken for graft to function (Yarlagadda et al., 2009; Willicombe et al., 2017), (Gut) increased diarrheal episodes (Lee et al., 2014), and (Urinary Tract) increases in urinary tract infections (Giessing, 2012). Microbial changes include: (Oral) increased abundance of Candida species (Spolidorio et al., 2006), total viable microorganism counts (Saraiva et al., 2006), and relative abundance of opportunistic pathogens (Diaz et al., 2013), (Gut) increased relative abundance of Proteobacteria (Lee et al., 2014), changes in microbial metabolism between (i) immunosuppressive regimens (Zaza et al., 2017), as well as microbial community structure in (ii) rejection and non-rejection patients (Lee et al., 2014) and (iii) diarrheal and non-diarrheal patients (Lee et al., 2019). (Urinary Tract) Structurally different microbiomes are also seen in transplant recipients (Fricke et al., 2014), as well as chronic allograft dysfunction (Wu et al., 2018) and interstistal fibrosis and tubular atrophy patients (Modena et al., 2017).