Impact of agricultural runoff and domestic sewage discharge on the spatial-temporal occurrence of emerging contaminants in an urban stream in São Paulo, Brazil.

Ribeirão das Pedras, a 10-km-long stream from the source to mouth, is part of a predominantly urban catchment located in Campinas metropolitan area in the state of São Paulo, Brazil, and it is also surrounded by sugarcane farms. Monthly sampling of 31 selected emerging contaminants (ECs) was conducted for 1 year (October 2018 to October 2019) in five points, including the spring, agricultural, and urban areas, to assess the dynamics and impact of ECs on the stream. The ECs were quantified using LC-MS/MS analysis. Out of the 31 ECs monitored in this study, 13 were detected in the Ribeirão das Pedras catchment, which were mainly pesticides and caffeine. Eight ECs (hexazinone, malathion, desethylatrazine (DEA), desisopropylatrazine (DIA), fipronil, ametryn, 2-hidroxyatrazine, and diuron) were detected with risk quotients higher than 1, indicating some level of environmental concern. Statistical analyses showed that caffeine, hexazinone, atrazine, DEA, and DIA were the most statistically important contaminants in temporal analysis, with caffeine concentrations varying randomly. Hexazinone, atrazine, DIA, and DEA concentrations increased from November 2018 to January 2019, and atrazine, hexazinone, and DEA concentrations increased from June 2019 to September 2019. Spatial analysis indicates that the spring of Ribeirão das Pedras is the only statistically different sampling point, with lower concentrations of EC. Points 3 and 5, both located in urban areas next to the stream's mouth, differ from each other due to the possible dilution of caffeine downstream of point 3 and domestic sewage discharge upstream of point 5.

Does Low-Protein Diet Influence the Uremic Toxin Serum Levels From the Gut Microbiota in Nondialysis Chronic Kidney Disease Patients?

OBJECTIVES: To evaluate the effects of low-protein diet (LPD) on uremic toxins and the gut microbiota profile in nondialysis chronic kidney disease (CKD) patients. DESIGN AND METHODS: Longitudinal study with 30 nondialysis CKD patients (stage 3-4) undergoing LPD for 6 months. Adherence to the diet was evaluated based on the calculation of protein equivalent of nitrogen appearance from the 24-hour urine analysis. Good adherence to LPD was considered when protein intake was from 90% to 110% of the prescribed amount (0.6 g/kg/day). Food intake was analyzed by the 24-hour recall method. The anthropometric, biochemical and lipid profile parameters were measured according to standard methods. Uremic toxin serum levels (indoxyl sulfate, p-cresyl sulfate, indole-3-acetic acid) were obtained by reversed-phase high-performance liquid chromatography (RP-HPLC). Fecal samples were collected to evaluate the gut microbiota profile through polymerase chain reaction and denaturing gradient gel electrophoresis. Statistical analysis was performed by the SPSS 23.0 program software. RESULTS: Patients who adhered to the diet (n = 14) (0.7 ± 0.2 g/kg/day) presented an improvement in renal function (nonsignificant) and reduction in total and low-density lipoprotein cholesterol (183.9 ± 48.5-155.7 ± 37.2 mg/dL, P = .01; 99.4 ± 41.3-76.4 ± 33.2 mg/dL, P = .01, respectively). After 6 months of nutricional intervention, p-cresyl sulfate serum levels were reduced significantly in patients who adhered to the LPD (19.3 [9.6-24.7] to 15.5 [9.8-24.1] mg/L, P = .03), and in contrast, the levels were increased in patients who did not adhere (13.9 [8.0-24.8] to 24.3 [8.1-39.2] mg/L, P = .004). In addition, using the denaturing gradient gel electrophoresis technique, it was observed change in the intestinal microbiota profile after LPD intervention in both groups, and the number of bands was positively associated with protein intake (r = 0.44, P = .04). CONCLUSION: LPD seems be a good strategy to reduce the uremic toxins production by the gut microbiota in nondialysis CKD patients.

Maternal use of flaxseed oil during pregnancy and lactation prevents morphological alterations in pancreas of female offspring from rat dams with experimental diabetes.

Nutritional recommendations have promoted the increased need to consume n-3 polyunsaturated fatty acids. Flaxseed is the richest dietary source of n-3 fatty acids among plant sources and is widely used for its edible oil. This study aimed to investigate whether maternal use of flaxseed oil has effects on pancreas morphology in the female offspring of diabetic mothers. Female Wistar rats (n = 12) were induced into diabetes by a high-fat diet and low dose of streptozotocin. After confirmation of the diabetes, rats were mated, and once pregnancy was confirmed, they were allocated into three groups (n = 6): high-fat group (HG); flaxseed oil group (FOG); and control group (CG) (non-diabetic rats). At weaning, female offspring (n = 6/group) received standard chow diet. The animals were euthanized at 180 days. Pancreas was collected for histomorphometric and immunohistochemistry analysis. HG showed hypertrophy of pancreatic islets (P < 0.0001), whereas FOG offspring had islets with smaller diameters compared to HG (P < 0.0001). HG offspring showed higher percentage of larger (P = 0.0061) and lower percentage of smaller islets (P = 0.0036). HG showed lower islet insulin immunodensity at 180 days (P < 0.0001), whereas FOG was similar to CG (P < 0.0001). Flaxseed oil reduced the damage caused by maternal hyperglycaemia, promoting normal pancreas histomorphometry and ß-cell mass in female offspring.

Oral iron supplementation in patients with chronic kidney disease: Can it be harmful to the gut microbiota?

Patients with chronic kidney disease (CKD) have several pathophysiological alterations, including anemia, one of the first changes in CKD patients. More recently, researchers have observed that the intestinal microbiota alterations are also another complication in these patients. The most common treatment for anemia is oral (mainly ferrous sulfate) or intravenous iron supplementation. Despite being a necessary treatment, recent studies have reported that supplementation with oral iron may increase its availability in the intestine, leading to disturbance in the gut microbiota and also to oxidative stress in the enterocytes, which may change the permeability and the microbiota profile. Although it is a therapy routinely used in patients with CKD, supplementation with oral iron on the gut microbiota has been rarely studied in these patients. Thus, this review will discuss the relationship between iron and the gut microbiota and the possible effects of oral iron supplementation on gut microbiota in patients with CKD.

Red meat intake in chronic kidney disease patients: Two sides of the coin.

Red meat is an important dietary source of high biological value protein and micronutrients such as vitamins, iron, and zinc that exert many beneficial functions. However, high consumption of animal protein sources, especially red meat, results in an increased intake of saturated fat, cholesterol, iron, and salt, as well as an excessive acid load. Red meat intake may lead to an elevated production of uremic toxins by the gut microbiota, such as trimethylamine n-oxide (TMAO), indoxyl sulfate, and p-cresyl sulfate. These uremic toxins are associated with increased risk for cardiovascular (CV) mortality. Limiting the intake of red meat in patients with chronic kidney disease (CKD) thus may be a good strategy to reduce CV risk, and may slow the progression of kidney disease. In the present review, we discuss the role of red meat in the diet of patients with CKD. Additionally, we report on a pilot study that focused on the effect of a low-protein diet on TMAO plasma levels in nondialysis CKD patients.

Indução de Diabetes Tipo 2 por dieta hiperlipídica e baixa dose de estreptozotocina em ratas wistar / Induction of Type 2 Diabetes by low dose of streptozotocin and high-fat diet-fed in wistar rats

O objetivo do presente estudo experimental foi desenvolver um modelo animal de diabetes tipo 2 que mimetizasse o curso natural e metabólico desta doença em humanos. Assim, foi oferecida uma dieta hiperlipídica (com aproximadamente 60% das calorias totais provenientes de lipídeos) por três semanas, estabelecendo então, um quadro de resistência à insulina. Em seguida, as ratas foram submetidas a uma dose única de estreptozotocina (STZ) (35mg/kg de peso corporal) em veículo de tampão citrato (pH: 4,4). Após 1 semana da injeção de STZ, as ratas foram submetidas ao teste oral de tolerância à glicose, mediante administração oral de glicose (2g glicose/kg de massa corporal). Os dados foram submetidos à comparação entre os grupos utilizando-se o teste t. A significância em todos os testes se deu ao nível de p ≤ 0,05. O grupo controle manteve a concentração média de glicose final igual a inicial. Após ingestão da dieta hiperlipídica houve um aumento da glicemia de jejum em cerca de 16,5% em relação ao momento inicial do experimento (P<0,0001) enquanto os animais que receberam a dieta controle apresentaram um aumento aproximado de 8,7%. Uma semana após a administração intraperitoneal de STZ, pode-se verificar aumento da concentração média de glicose no grupo hiperlipídico em cerca de 194,2%, representando um aumento de 275,8% (P<0,0001) quando comparado ao GC. O presente estudo retrata que a combinação de uma dieta hiperlipídica e baixa dose de estreptozotocina serve como um modelo animal alternativo para a diabetes tipo 2 simulando a síndrome em humanos

The objective of the present experimental study is to develop an animal model of type 2 diabetes which mimics the natural and metabolic course of this disease in humans. Therefore, a high-fat diet (with approximately 60% of the calories from lipidis) was offered for 3 weeks, establishing an insulin resistant picture. After, the female rats were submitted to a single dose of streptozotocin (STZ) (35mg/kg of bodymass) using citrate buffer (pH:4,4). After a week of the injection of STZ, the female rats were submitted to the glucose tolerance oral test, by oral administration of glucose (2g glucose/ kg of body mass). The data was compared between groups using the test t. The significance in all tests was on level of p<0,05. The control group kept the final average glucose concentration equals to the initial. After the ingestion of the high-fat diet an increase of 16,5% of the fasting glucose happened compared to the initial moment of the experiment (P<0,0001) while the animals that received the control diet presented an increase of approximately 8,7%. One week after the intraperitoneal administration of STZ, the high-fat feed group showed anincrease of about 194,2% of the average concentration of glucose, representing an increase of about 275,8% (P<0,0001) when compared to the control group. The present study shows that the combinationof a high-fat diet and low dose of streptozotocin works as an alternative animal model for type 2 diabetes simulating the disease in humans.