The aim of this study is to evaluate the effects of Brazil nut supplementation on inflammation, oxidative stress and intestinal microbiota in patients with chronic kidney disease undergoing conservative treatment.

Complications such as inflammation and oxidative stress are common in chronic kidney disease (CKD) and directly influence the rate of disease progression. Patients with CKD also have intestinal dysbiosis, which aggravates the inflammatory process and oxidative stress, forming a vicious circle between inflammation, oxidative stress and intestinal dysbiosis. Nutritional strategies try to alleviate this circle and Brazil nuts, rich in bioactive compounds, have already been proven effective in mitigating inflammation and oxidative stress in CKD patients on dialysis. However, to date, the effectiveness of Brazil nuts in patients with CKD in stages prior to dialysis (conservative treatment) has not been tested. The bioactive compounds in Brazil nuts are expected to contribute positively to the redox balance, reduction of inflammation and intestinal eubiosis in patients with CKD undergoing conservative treatment.

Inclusion Criteria:

• Patients with more than three months of nutritional monitoring at the Renal Nutrition Outpatient Clinic of the Universidade Federal Fluminense (UFF), between stages G3a and G4, will be included, according to KDOQI 2020 guidelines, and authorized by the medical and nutritionist team.

Exclusion Criteria:

• Current use or in the last three months of antibiotics, anti-inflammatories and/or antioxidant supplements. Patients who are allergic, intolerant, or regularly ingest Brazil nuts; pregnant/lactating women, smokers; undergoing cancer treatment, HIV-positive, or with any clinical condition that compromises the accuracy of the intervention.