Gut microbiota dynamics and association with chronic kidney disease: A longitudinal study within the PREDIMED-Plus trial

Chronic kidney disease (CKD) represents a global health concern, disproportionately affecting the elderly with heightened cardiovascular risk. The emerging focus on the gut microbiota's role in CKD pathophysiology represents a pivotal area in nephrology; however, the evidence on this topic is limited. This observational prospective study, in the framework of the PREDIMED-Plus trial, investigates associations between gut microbiota composition and the 1-year trajectory of CKD in 343 participants aged 55–75 years with high cardiovascular risk. Kidney function was assessed at baseline and at 1-year of follow-up through the estimated glomerular filtration rate based on cystatin C (eGFR-CysC) and CKD defined by eGFR-CysC <60 mL/min/1.73 m2. Participants were grouped based on their 1-year CKD trajectory: Group 1 maintained normal status or improved from CKD to normal, while Group 2 maintained CKD or worsened from normal to CKD. Fecal microbiota composition was assessed through 16S sequencing. We observed differences in gut microbiota composition between CKD trajectory groups. Notably, the baseline relative abundance of Lachnoclostridium and Lachnospira, both butyrate-producing genera, was lower in participants maintaining or progressing to CKD. Longitudinally, a decrease in Lachnospira abundance was associated with CKD progression. The improved Chao1 index after 1-year follow-up suggests a link between enhanced microbial richness and stable/better kidney function. The findings underscore the potential of gut microbiota analysis in non-invasively monitoring CKD, especially in older populations, and hint at future interventions targeting gut microbiota to manage CKD progression. Further research is needed for causal relationships and generalizability.