Zinc Supplementation Partially Decreases the Harmful Effects of a Cafeteria Diet in Rats but Does Not Prevent Intestinal Dysbiosis.

Zinc (Zn) plays an important role in metabolic homeostasis and may modulate neurological impairment related to obesity. The present study aimed to evaluate the effect of Zn supplementation on the intestinal microbiota, fatty acid profile, and neurofunctional parameters in obese male Wistar rats. Rats were fed a cafeteria diet (CAF), composed of ultra-processed and highly caloric and palatable foods, for 20 weeks to induce obesity. From week 16, Zn supplementation was started (10 mg/kg/day). At the end of the experiment, we evaluated the colon morphology, composition of gut microbiota, intestinal fatty acids, integrity of the intestinal barrier and blood-brain barrier (BBB), and neuroplasticity markers in the cerebral cortex and hippocampus. Obese rats showed dysbiosis, morphological changes, short-chain fatty acid (SCFA) reduction, and increased saturated fatty acids in the colon. BBB may also be compromised in CAF-fed animals, as claudin-5 expression is reduced in the cerebral cortex. In addition, synaptophysin was decreased in the hippocampus, which may affect synaptic function. Our findings showed that Zn could not protect obese animals from intestinal dysbiosis. However, an increase in acetate levels was observed, which suggests a partial beneficial effect of Zn. Thus, Zn supplementation may not be sufficient to protect from obesity-related dysfunctions.

Selenium inadequacy is not associated with oxidative stress in child and adolescent acute lymphocytic leukemia survivors.

OBJECTIVE: Acute lymphocytic leukemia (ALL) and its subsequent treatment may provoke increased oxidative stress. The aim of this study was to investigate the antioxidant status of children and adolescents who had received ALL therapy, and to test the hypothesis that selenium (Se) inadequacy is correlated with reduced defenses against oxidative stress in this population. METHODS: This case-control study involved 24 patients between ages 5 and 13 y who had been treated successfully for ALL (ALL group) and 60 children of similar age and socioeconomic background with no clinical history of leukemia (control group). Dietary intake of Se was evaluated by the 24-h recall method, and the concentrations of Se in plasma, erythrocytes, and urine determined. Antioxidant status was assessed by analysis of the oxidative stress markers, namely, superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), α-tocopherol, and 8-oxo-deoxyguanosine (8-oxo-dG). RESULTS: There were no between-group differences with respect to plasma (P = 0.122), erythrocyte (P = 0.202), urinary (P = 0.608), or dietary (P = 0.757) levels of Se. GPx activity was significantly (P < 0.001) reduced in the ALL group compared with the control group, whereas SOD activity and MDA concentrations were similar. The concentrations of α-tocopherol and 8-oxo-dG were significantly increased in the ALL group compared with the control group (P < 0.001 and P = 0.031, respectively). CONCLUSION: All participants were Se inadequate, but such inadequacy was not correlated with reduced defenses against oxidative stress. However, individuals of the ALL group were with increased oxidative stress compared with the control group, possibly due to previous disease and to intensive polychemotherapy.