Functional effects of yacon (Smallanthus sonchifolius) and kefir on systemic inflammation, antioxidant activity, and intestinal microbiome in rats with induced colorectal cancer.

Colorectal cancer (CRC) is one of the most common cancers with high morbidity and mortality. The modulation of intestinal health through the administration of pro- and prebiotics may be a viable alternative to reduce the risk of CRC. This study aimed to evaluate the functional effects of yacon and kefir, isolated or associated, in rats with colorectal cancer. Adult Wistar rats were divided into five groups (n = 8): HC (healthy control AIN-93M diet), CC (CCR + AIN-93M diet), Y (CCR + AIN-93 M + yacon diet), K (CCR + AIN-93-M + kefir diet) and YK (CCR + AIN-93 M + yacon + kefir diet). Colorectal carcinogenesis was induced in groups CC, Y, K, and YK with 1,2-dimethylhydrazine (55 mg kg-1, subcutaneously) for 5 weeks. From the 6th week onwards, the experimental groups were fed the respective diets. In the 15th week, urine was collected for analysis of intestinal permeability and then the animals were euthanized. Yacon increased acetate levels, reduced pH and carcinogenic neoplastic lesions, and increased the abundance of bacteria related to the fermentation of non-digestible carbohydrates, such as the genera Dorea, Collinsela, and Bifidobacteria. On the other hand, kefir increased macroscopic neoplastic lesions and increased the abundance of Firmicutes and Clostridium. The association of yacon + kefir increased the number of carcinogenic lesions, despite a reduction in pH and beneficial bacteria prevalence. Thus, it is concluded that yacon, unlikely kefir, is a promising alternative to mitigate the manifestations of induced carcinogenesis in rats.

Yacon (Smallanthus sonchifolius) and kefir improved intestinal and bone health but without symbiotic benefits in rats.

Kefir is a natural source of probiotics, and yacon (Smallanthus sonchifolius) is a tuberous root rich in fructooligosaccharides, with prebiotic properties. We hypothesized that kefir and yacon can improve bone and intestinal health and that their synbiotic effects will enhance these benefits. The properties of yacon and kefir and their association were evaluated in the intestinal and bone health in rats. Forty Wistar male rats were divided into 4 groups (n = 10): control (C), kefir (K), yacon (Y), and yacon + kefir (YK) and received an AIN-93 M diet containing 50% of the daily recommendation of calcium for 42 days. Group K received 1 mL/day of kefir containing 108 CFU/mL; group Y received yacon flour (5% fructooligosaccharides); and the YK group received the same treatment as the Y and K groups. Urine and feces were collected to determine the calcium balance. Serum biomarkers of bone formation and resorption, osteocalcin, N telopeptides of collagen type I and C-telopeptide of collagen type I, intraluminal pH, intestinal permeability, and secretory immunoglobulin A were evaluated. Yacon reduced intraluminal pH alone or in association with kefir (groups Y and YK). Yacon also improved intestinal permeability (lowered lactulose and mannitol excretion) and increased calcium balance and osteocalcin, a biomarker of bone formation. In turn, K improved immunity by increasing secretory immunoglobulin A secretion and reducing bone resorption biomarkers (C-telopeptide of collagen type I and N telopeptides of collagen type I). Thus, yacon and kefir had beneficial effects on intestinal and bone health; however, the association between them did not demonstrate a synbiotic effect.

Yacon (Smallanthus sonchifolius) Flour Reduces Inflammation and Had No Effects on Oxidative Stress and Endotoxemia in Wistar Rats with Induced Colorectal Carcinogenesis.

Colorectal cancer has a high worldwide incidence. The aim of this study was to determine the effect of yacon flour (YF) on oxidative stress, inflammation, and endotoxemia in rats with induced colorectal cancer (CRC). The Wistar male rats were divided and kept for 8 weeks in four groups: S (basal diet, n = 10), Y (YF flour + basal diet, n = 10), C (CRC-induced control + basal diet, n = 12), CY (CRC-induced animals + YF, n = 12). CRC was induced by intraperitoneal injections of 1,2-dimethylhydrazine (25 mg/kg body weight). Groups Y and CY received 7.5% of the prebiotic FOS from YF. The treatment with YF increased fecal secretory immunoglobulin A levels and decreased lipopolysaccharides, tumor necrosis factor alpha and interleukin-12. However, no effect was observed on the oxidative stress by the total antioxidant capacity of plasma, anion superoxide, and nitric oxide analysis of the animals (p < 0.05). The short-chain fatty acids acetate, propionate, and butyrate showed interactions with NF-κB, TLR4, iNOS, and NADPH oxidase by in silico analysis and had a correlation (by the Person analysis) with CRC markers. The yacon flour treatment reduced the inflammation in rats with induced CRC, and could be a promising food to reduce the damages caused by colorectal cancer.

Brown and golden flaxseed reduce intestinal permeability and endotoxemia, and improve the lipid profile in perimenopausal overweight women.

The effect of brown and golden flaxseeds on lipid profile, oxidative stress, intestinal permeability, endotoxemia, and fasting glycaemia of perimenopausal overweight women was investigated in this clinical trial. Thirty participants were divided into control (CG), brown flaxseed (BF), and golden flaxseed (GF) groups. BF and GF received 40 g of brown and golden flaxseed for 12 weeks. Venous blood samples were collected at the beginning and at the end. Intestinal permeability analysis was performed by urinary excretion of lactulose and mannitol. There was significant reduction in intestinal permeability in flaxseed groups, with delta of lactulose/mannitol ratio smaller (p ≤ 0.05). LPS levels were reduced in the flaxseed groups, whereas low-density lipoproteins (LDL) was decreased in the GF group (p ≤ 0.05). Flaxseed consumption did not change oxidative stress markers and glycaemia. Flaxseed consumption, especially golden flaxseed, reduced intestinal permeability and improved the lipid profile, showing positive effects on metabolic changes caused by menopausal transition.HIGHLIGHTSBrown and golden flaxseeds show a high content of insoluble fibre and alpha-linolenic acid, and brown flaxseed presented higher antioxidant activity.Golden flaxseed improved the lipid profile.Brown and golden flaxseeds reduced intestinal permeability and endotoxemia.Brown and golden flaxseed can be a promising alternative for the prevention of metabolic changes caused by menopausal transition, and for the improvement of the intestinal health.

Efeito da farinha de yacon (Smallanthus sonchifolius) na resposta imunológica intestinal no câncer colorretal / Effect of yacon meal (Smallanthus sonchifolius) on the intestinal immune response in colorectal cancer

Introdução: O câncer colorretal (CC) pode induzir graves complicações clínicas aos portadores dessa neoplasia. A farinha de yacon (FY) (Smallanthus sonchifolius) é rica em fruto-oligossacarídeos (FOS), que são fermentados por bifidobactérias, produzindo efeitos benéficos à saúde intestinal. Seu efeito no CC, entretanto, é ainda desconhecido, sendo o objetivo deste trabalho investigar os efeitos da FY sobre a resposta imunológica de mucosa em animais com CC induzido. Método: Ratos machos Wistar (n=44) foram divididos em grupo S (sem CC e sem FY na dieta), grupo C (com CC e sem FY na dieta), grupo Y (sem CC e com FY na dieta) e grupo CY (com CC e FY na dieta). Durante cinco semanas, os grupos C e CY receberam injeções de 1,2-Dimetilhidrazina para o desenvolvimento do CC, seguidas por duas semanas para formação das lesões neoplá- sicas. Após esse período, os grupos Y e CY consumiram dieta com FY em quantidades suficientes para fornecer 7,5% de FOS por duas semanas e os demais grupos consumiram dieta AIN-93M. Resposta imunológica da mucosa intestinal foi determinada pela dosagem de imunoglobulina A secretória (sIgA) nas fezes pelo método de ELISA. Dados foram avaliados por ANOVA e teste t pareado (p<0,05). Resultados: Após suplementação com FY na dieta, os níveis de sIgA no grupo CY foram superiores aos do grupo S. No grupo CY, os níveis de sIgA aumentaram quando comparados o início e final da intervenção. Conclusão: A FY foi capaz de aumentar os níveis da IgA fecal nos animais com CC.(AU)

Introduction: Colorectal cancer (CC) can induce serious clinical complications in patients with this neoplasm. Yacon flour (YF) (Smallanthus sonchifolius) is rich in fructooligosaccharides (FOS) that are fermented by bifidobacteria producing beneficial effects on intestinal health. Its effect on CC, however, is still unknown, and the objective of this work is to investigate the effects of YF on the immune response of mucosa in animals with induced CC. Methods: Male Wistar rats (n=44) were divided into group S (without CC and without YF in the diet), group C (with CC and without YF in the diet), group Y (without CC and with YF in the diet) And CY group (with CC and YF in the diet). For five weeks, groups C and CY received injections of 1,2-Dimethylhydrazine for the development of CC, followed by two weeks for the formation of neoplastic lesions. After this period, groups Y and CY consumed diet with YF in amounts sufficient to provide 7.5% of FOS for two weeks and the other groups, consumed diet AIN-93M. Immune response of intestinal mucosa was determined by secretory immunoglobulin A (sIgA) dosing in feces by the ELISA method. Data were evaluated by ANOVA and paired t-test (p<0.05). Results: After supplementation with YF in the diet, sIgA levels in the CY group were higher than those in the S group. In the CY group, sIgA levels increased when compared to the beginning and end of the intervention. Conclusion: FY was able to increase faecal IgA levels in animals with CC.(AU)

Yacon effects in immune response and nutritional status of iron and zinc in preschool children.

OBJECTIVE: The aim of this study was to evaluate the effect of yacon flour on iron and zinc nutritional status and immune response biomarkers in preschool children. METHODS: Preschool children ages 2 to 5 y were selected from two nurseries and were placed into a control group (n = 58) or a yacon group (n = 59). The yacon group received yacon flour in preparations for 18 wk at a quantity to provide 0.14 g of fructooligosaccharides/kg of body weight daily. Anthropometric parameters were measured before and after the intervention and dietary intake was measured during the intervention. To assess iron and zinc status, erythrograms, serum iron, ferritin, and plasma, and erythrocyte zinc were evaluated. Systemic immune response was assessed by the biomarkers interleukin IL-4, IL-10, IL-6, and tumor necrosis factor-alfa (TNF-α). Intestinal immune response was analyzed by secretory IgA (sIgA) levels before and after the intervention. Statistical significance was evaluated using the paired t test (α = 5%). RESULTS: Before and after the study, the children presented a high prevalence of overweight and an inadequate dietary intake of zinc and fiber. The yacon group presented with lower hemoglobin, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration at the end of the study (P < 0.05). Erythrocyte zinc was reduced in both groups at the end of the study (P < 0.05). Yacon intake increased the serum levels of IL-4 and fecal sIgA (P < 0.05). The control group had lower serum TNF-α after the study period (P < 0.05). CONCLUSION: Yacon improved intestinal immune response but demonstrated no effect on the nutritional status of iron and zinc in preschool children.

The role of L-arginine-nitric oxide pathway in bacterial translocation.

This study investigated the nitric oxide (NO) role as a mediator of arginine on bacterial translocation (BT) and gut damage in mice after intestinal obstruction (IO). The effects of pretreatment with arginine with or without NO inhibition on the systemic and local immunological response were also assessed. Mice were categorized into four groups. Group ARG received chow containing 2 % arginine, while group ARG + L-NAME received the same diet plus L-NAME (N-nitro-L-arginine methyl ester) by gavage. The IO and Sham groups were fed standard chow. After 7 days, animals were gavaged with radiolabeled Escherichia coli, anesthetized and subjected to IO, except the Sham group. Animals were euthanized after 18 h, and BT was evaluated in the mesenteric lymph nodes, blood, liver, spleen and lungs. In another experiment, the intestinal injury was assessed regarding intestinal permeability and ileum histological analyses. Intestinal secretory immunoglobulin A (sIgA) levels, serum IFN-γ and IL-10 cytokines were assessed. Arginine reduced BT, but NO inhibition enhanced BT compared with the ARG group (p < 0.05). Intestinal permeability in the ARG and ARG + L-NAME groups was similar but decreased when compared with the IO group (p < 0.05). Histological preservation was observed. Arginine treatment increased IL-10 and sIgA levels when compared with the Sham and IO groups (p < 0.05). The cytokines and sIgA concentrations were similar in the ARG + L-NAME and Sham groups. Arginine appeared to reduce BT and its effects on the modulation of cytokines and secretory IgA in mice after IO are mediated by NO production.

Glutamine supplementation decreases intestinal permeability and preserves gut mucosa integrity in an experimental mouse model.

BACKGROUND: Glutamine (GLN) is the preferred fuel for enterocytes, and GLN supplementation is critical during stressful conditions. The aim of this study was to evaluate the effect of GLN on intestinal barrier permeability and bacterial translocation in a murine experimental model. METHODS: Swiss male mice (25-30 g) were randomized into 3 groups: (1) sham group; (2) intestinal obstruction (IO) group; (3) IO and GLN (500 mg/kg/d) group. Two different experiments were carried out to assess intestinal permeability and bacterial translocation. In the first experiment, the animals were divided into the 3 groups described above and received diethylenetriamine pentaacetate radiolabeled with technetium ((99m)Tc) on the eighth day. At different time points after intestinal obstruction, blood was collected to determine radioactivity. The animals were killed, and the small intestine was removed for histological analyses. In the bacterial translocation study, on the eighth day all groups received Escherichia coli labeled with (99m)Tc. After 90 minutes, the animals underwent intestinal obstruction and were killed 18 hours later. Blood, mesenteric lymph nodes, liver, spleen, and lungs were removed to determine radioactivity. Statistical significance was considered when P < or = .05. RESULTS: The levels of intestinal permeability and bacterial translocation were higher in the IO group than in the sham and GLN groups (P < .05). GLN decreased intestinal permeability and bacterial translocation to physiologic levels in the treated animals and preserved intestinal barrier integrity. CONCLUSIONS: GLN had a positive impact on the intestinal barrier by reducing permeability and bacterial translocation to physiologic levels and preserving mucosal integrity.