Gut microbiota has received significant attention owing to its decisive role in human health and disease. Diet exerts a significant influence on the variety and number of bacteria residing in the intestinal epithelium. On the other hand, as iron is a key micronutrient for blood formation and oxygen supply, its deficiency is highly prevalent worldwide. In fact, it is the most common cause of anemia and thus, iron supplementation is widespread. However, there is concern due to some potential risks linked to iron supplementation. Therefore, we have reviewed the available evidence of the effects that iron supplementation exerts on the gut microbiota as well as its potential benefits and risks. The compiled information suggests that iron supplementation is potentially harmful for gut microbiota. Therefore, it should be performed with caution, and by principle, recommended only to individuals with proven iron deficiency or iron-deficiency anemia to avoid potential adverse effects. In any case, large and long-term population studies are urgently needed to confirm or refute these results, mainly focused on vulnerable populations.

Nutritional monitoring in advanced chronic kidney disease (ACKD) units provides personalized care and improves clinical outcomes. This study aimed to identify mortality risk factors in chronic kidney disease (CKD) patients on nutritional follow-up in the multidisciplinary ACKD unit. A retrospective cross-sectional observational study was conducted in 307 CKD patients’ stage 3b, 4–5 followed-up for 10 years. Clinical and nutritional monitoring was performed by malnutrition-inflammation score (MIS), biochemical parameters (s-albumin, s-prealbumin, and serum C-reactive protein (s-CRP), body composition measured by bioelectrical impedance analysis (BIA), anthropometry, and handgrip strength measurements. The sample was classified into non-survivors, survivors, and censored groups. Of the 307 CKD patients, the prevalence of protein-energy wasting (PEW) was 27.0% using MIS > 5 points, s-CRP > 1 mg/dL was 19.20%, and 27.18% died. Survivors had higher significant body cell mass (BCM%) and phase angle (PA). Survival analyses significantly showed that age > 72 years, MIS > 5 points, s-prealbumin ≤ 30 mg/dL, PA ≤ 4°, and gender-adjusted handgrip strength (HGS) were associated with an increased risk of mortality. By univariate and multivariate Cox regression, time on follow-up (HR:0.97), s-prealbumin (HR:0.94), and right handgrip strength (HR:0.96) were independent predictors of mortality risk at 10 years of follow-up in the ACKD unit. Nutritional monitoring in patients with stage 3b, 4–5 CKD helps to identify and treat nutritional risk early and improve adverse mortality prognosis.

Background. The bioactive components of plant foods and medicinal plants have attracted interest due to their potential impact on the progression of chronic kidney disease (CKD) and outcomes. Objective. This study aimed to conduct a critical and quantitative systematic review of randomized clinical trials (RCTs) investigating the potential effects of selected phytochemicals from plant-based foods and medicinal plants in CKD and dialysis patients. Methods. The review included studies that related plant-based bioactive compounds (curcumin, propolis, sulforaphane, betalain, catechins, rhein, emodin, aloe-emodin, flavonoids, and triptolide) and medicinal plants (green tea, rhubarb, Astragalus membranaceus, and Tripterygium wilfordii Hook F) in CKD and dialysis patients. A literature search was conducted in PubMed, LILACS, Embase, Scopus, and WOS between December 2022 and October 2024. This review was performed according to the PRISMA flowchart and was registered in PROSPERO (595162). Results. In the eight RCTs conducted with curcumin, anti-inflammatory, antioxidant, and microbiota-modulating properties were reported. As for propolis, in three RCTs, anti-inflammatory, anti-proteinuric, and renal-protective properties were reported. Sulforaphane in one RCT showed antioxidant and cardiovascular benefits, and in another RCT no effects were observed. In one RCT, genistein was shown to be a potential anti-inflammatory agent and improved nutritional status. Allicin in two RCTs showed cardioprotective, antioxidant, anti-inflammatory, and lipid-lowering effects. Finally, beetroot showed a vasodilator effect in one RCT. As for the medicinal plants, green tea, rhubarb, Astragalus membranaceus, and Tripterygium Wilfordii Hook F, in six RCTs they showed antioxidant, anti-inflammatory, cardioprotective, antiproteinuric, and renoprotective properties. Conclusions. These results suggest that bioactive compounds of plant-based foods and medicinal plants have promising effects in terms of preventing or treating CKD progression and appear to improve inflammation and antioxidant capacity and support cardiovascular benefits and renoprotective effects; however, it is recommended that further studies be carried out.