The purpose of the present study was to identify the association of the Pro12Ala polymorphism in the PPAR-γ2 gene with diabetes, insulinaemia and insulin resistance. A meta-analysis study was carried out based on studies conducted in the last 10 years, using the databases PubMed, ISI Web of Knowledge, High Wire Press and Scielo, and the reference lists of the obtained articles. We included original studies that showed the relationship between the Pro12Ala polymorphism in the PPAR-γ2 gene and type 2 diabetes mellitus (T2DM), insulinaemia and insulin resistance. Statistical analyses were conducted using the program RevMAn 5.0. The Mantel–Haenszel test was used to estimate the OR and the 95 % CI of the dichotomous variable, while the standardised effect size was used to estimate the average standardised mean difference and 95 % CI of continuous variables. The studies were subgrouped by ethnicity and overweight status. Forty-one studies were analysed, including a global sample of 30 612 subjects. We found a significant association of the Ala allele with the lowest risk of T2DM in Caucasians (OR 0·80; 95 % CI 0·65, 0·98), lower serum insulin (standardised effect size: − 0·05; 95 % CI − 0·09, − 0·00; P = 0·04), and greater sensitivity to insulin in overweight individuals (homeostasis model assessment of insulin resistance standardised effect size: − 0·07; 95 % CI − 0·13, − 0·01; P = 0·02). Considering that the Pro12Ala polymorphism in the PPAR-γ2 gene is one of the factors related to insulin sensitivity, the present study demonstrated a significant effect of the Ala allele on lower development of T2DM in Caucasians and greater sensitivity to insulin in overweight subjects.

Dietary fibre is fermented by the human gut flora resulting mainly in the formation of SCFA, for example, acetate, propionate and butyrate. SCFA, in particular butyrate, may be important for secondary cancer prevention by inducing apoptosis and inhibiting cell growth of cancer cells, thereby inhibiting the promotion and/or progression of cancer. Furthermore, SCFA could also act on primary cancer prevention by activation of detoxifying and antioxidative enzymes. We investigated the effects of fermented wheat aleurone on the expression of genes involved in stress response and toxicity, activity of drug-metabolising enzymes and anti-genotoxic potential. Aleurone was digested and fermented in vitro to obtain samples that reflect the content of the colon. HT29 cells and colon epithelial stripes were incubated with the resulting fermentation supernatant fractions (fs) and effects on mRNA expression of CAT, GSTP1 and SULT2B1 and enzyme activity of glutathione S-transferase (GST) and catalase (CAT) were measured. Fermented aleurone was also used to study the protection against H2O2-induced DNA damage in HT29 cells. The fs of aleurone significantly induced the mRNA expression of CAT, GSTP1 and SULT2B1 (HT29) and GSTP1 (epithelial stripes), respectively. The enzyme activities of GST (HT29) and CAT (HT29, epithelial stripes) were also unambiguously increased (1·4- to 3·7-fold) by the fs of aleurone. DNA damage induced by H2O2 was significantly reduced by the fs of aleurone after 48 h, whereupon no difference was observed compared with the faeces control. In conclusion, fermented aleurone is able to act on primary prevention by inducing mRNA expression and the activity of enzymes involved in detoxification of carcinogens and antioxidative defence.

Randomised controlled trials (RCT) of mixed n-6 and n-3 PUFA diets, and meta-analyses of their CHD outcomes, have been considered decisive evidence in specifically advising consumption of ‘at least 5–10 % of energy as n-6 PUFA’. Here we (1) performed an extensive literature search and extracted detailed dietary and outcome data enabling a critical examination of all RCT that increased PUFA and reported relevant CHD outcomes; (2) determined if dietary interventions increased n-6 PUFA with specificity, or increased both n-3 and n-6 PUFA (i.e. mixed n-3/n-6 PUFA diets); (3) compared mixed n-3/n-6 PUFA to n-6 specific PUFA diets on relevant CHD outcomes in meta-analyses; (4) evaluated the potential confounding role of trans-fatty acids (TFA). n-3 PUFA intakes were increased substantially in four of eight datasets, and the n-6 PUFA linoleic acid was raised with specificity in four datasets. n-3 and n-6 PUFA replaced a combination of TFA and SFA in all eight datasets. For non-fatal myocardial infarction (MI)+CHD death, the pooled risk reduction for mixed n-3/n-6 PUFA diets was 22 % (risk ratio (RR) 0·78; 95 % CI 0·65, 0·93) compared to an increased risk of 13 % for n-6 specific PUFA diets (RR 1·13; 95 % CI 0·84, 1·53). Risk of non-fatal MI+CHD death was significantly higher in n-6 specific PUFA diets compared to mixed n-3/n-6 PUFA diets (P = 0·02). RCT that substituted n-6 PUFA for TFA and SFA without simultaneously increasing n-3 PUFA produced an increase in risk of death that approached statistical significance (RR 1·16; 95 % CI 0·95, 1·42). Advice to specifically increase n-6 PUFA intake, based on mixed n-3/n-6 RCT data, is unlikely to provide the intended benefits, and may actually increase the risks of CHD and death.

Epidemiological evidence suggests that polyphenols may, in part, explain the cardioprotective properties of fruits. This review aims to summarise the evidence for the effects of fruit polyphenols on four risk factors of CVD: platelet function, blood pressure, vascular function and blood lipids. This review includes human dietary intervention studies investigating fruits and their polyphenols. There was some evidence to suggest that fruits containing relatively high concentrations of flavonols, anthocyanins and procyanindins, such as pomegranate, purple grapes and berries, were effective at reducing CVD risk factors, particularly with respect to anti-hypertensive effects, inhibition of platelet aggregation and increasing endothelial-dependent vasodilation than other fruits investigated. Flavanone-rich fruits, such as oranges and grapefruits, were reported to have hypocholesterolaemic effects, with little impact on other risk factors being examined. However, the evidence was limited, inconsistent and often inconclusive. This is in part due to the heterogeneity in the design of studies, the lack of controls, the relatively short intervention periods and low power in several studies. Details of the polyphenol content of the fruits investigated were also omitted in some studies, negating comparison of data. It is recommended that large, well-powered, long-term human dietary intervention studies investigating a wider range of fruits are required to confirm these observations. Investigations into the potential synergistic effects of polyphenols on a combination of CVD risk markers, dose–response relationships and standardisation in methodology would facilitate the comparison of studies and also provide valuable information on the types of fruits which could confer protection against CVD.

The aim of diabetes management is to normalise blood glucose levels since improved blood glucose control is associated with fewer complications. Food affects blood glucose levels; however, there is no universal approach to the optimal diabetic diet and there is controversy about the usefulness of the low-glycaemic index (GI) diet. To assess the effects of low-GI diets on glycaemic control in diabetes, we conducted electronic searches of the Cochrane Library, MEDLINE, EMBASE and CINAHL. We assessed randomised controlled trials (RCT) with interventions >4 weeks that compared a low-GI diet with a higher-GI diet for type 1 or type 2 diabetes. Twelve RCT (n 612) were identified. There was a significant decrease in glycated Hb (HbA1c) with low-GI diet than with the control diet, indicating improved glycaemic control (seven trials, n 457, weighted mean difference (WMD) − 0·4 % HbA1c, 95 % CI − 0·7, − 0·20, P = 0·001). In four studies reporting the results for glycaemic control as fructosamine, three of which were 6 weeks or less in duration, pooled data showed a decrease in fructosamine (WMD − 0·23 mmol/l, 95 % CI − 0·47, 0·00, P = 0·05), n 141, with low-GI diet than with high-GI diet. Glycosylated albumin levels decreased significantly with low-GI diet, but not with high-GI diet, in one study that reported this outcome. Lowering the GI of the diet may contribute to improved glycaemic control in diabetes.

Dietary protein might modulate mucin flow and intestinal mucin gene expression. Since unheated phaseolin from Phaseolus vulgaris bean is resistant to digestion and increases gut endogenous protein losses, we hypothesised that unheated phaseolin influences mucin flow and gene expression, and that phaseolin heat treatment reverses these effects. The hypothesis was tested using a control diet containing casein as the sole protein source and three other diets with casein being replaced by 33 and 67 % of unheated and 67 % of heated phaseolin. The rats were fed for 6 d and euthanised. Digesta and faeces were collected for determining digestibility and mucin flow. Gut tissues were collected for mucin (Muc1, Muc2, Muc3 and Muc4) and Trefoil factor 3 (Tff3) gene expressions. Colonic mucin flow decreased linearly with increasing the dietary level of unheated phaseolin (P < 0·05). Unheated phaseolin increased N flow in ileum, colon and faeces (P < 0·05), and reduced apparent N digestibility linearly (P < 0·01). Heat treatment reversed all these changes (P < 0·05 to < 0·001), except mucin flow. The expressions of Muc mRNA in gut tissues were influenced by dietary phaseolin level (ileum and colon: Muc3 and Muc4) and thermal treatment (ileum: Muc2; colon: Muc2, Muc3, Muc4 and Tff3) (P < 0·05 to 0·001). In conclusion, phaseolin modulates mucin flow and Muc gene expression along the intestines differentially.

There is intense interest in the studies related to the potential of phytochemical-rich foods to prevent age-related neurodegeneration and cognitive decline. Recent evidence has indicated that a group of plant-derived compounds known as flavonoids may exert particularly powerful actions on mammalian cognition and may reverse age-related declines in memory and learning. In particular, evidence suggests that foods rich in three specific flavonoid sub-groups, the flavanols, anthocyanins and/or flavanones, possess the greatest potential to act on the cognitive processes. This review will highlight the evidence for the actions of such flavonoids, found most commonly in fruits, such as apples, berries and citrus, on cognitive behaviour and the underlying cellular architecture. Although the precise mechanisms by which these flavonoids act within the brain remain unresolved, the present review focuses on their ability to protect vulnerable neurons and enhance the function of existing neuronal structures, two processes known to be influenced by flavonoids and also known to underpin neuro-cognitive function. Most notably, we discuss their selective interactions with protein kinase and lipid kinase signalling cascades (i.e. phosphoinositide-3 kinase/Akt and mitogen-activated protein kinase pathways), which regulate transcription factors and gene expression involved in both synaptic plasticity and cerebrovascular blood flow. Overall, the review attempts to provide an initial insight into the potential impact of regular flavonoid-rich fruit consumption on normal or abnormal deteriorations in cognitive performance.

It has been reported that the artificial sweetener, sucralose, stimulates glucose absorption in rodents by enhancing apical availability of the transporter GLUT2. We evaluated whether exposure of the proximal small intestine to sucralose affects glucose absorption and/or the glycaemic response to an intraduodenal (ID) glucose infusion in healthy human subjects. Ten healthy subjects were studied on two separate occasions in a single-blind, randomised order. Each subject received an ID infusion of sucralose (4 mm in 0·9 % saline) or control (0·9 % saline) at 4 ml/min for 150 min (T = − 30 to 120 min). After 30 min (T = 0), glucose (25 %) and its non-metabolised analogue, 3-O-methylglucose (3-OMG; 2·5 %), were co-infused intraduodenally (T = 0–120 min; 4·2 kJ/min (1 kcal/min)). Blood was sampled at frequent intervals. Blood glucose, plasma glucagon-like peptide-1 (GLP-1) and serum 3-OMG concentrations increased during ID glucose/3-OMG infusion (P < 0·005 for each). However, there were no differences in blood glucose, plasma GLP-1 or serum 3-OMG concentrations between sucralose and control infusions. In conclusion, sucralose does not appear to modify the rate of glucose absorption or the glycaemic or incretin response to ID glucose infusion when given acutely in healthy human subjects.

Daily nutrition varies considerably among individuals. The number of vegetarians is increasing continuously due to ethical, environmental, religious or other reasons. There is growing concern over their nutritional status with respect to micronutrient deficiencies. Among the essential trace elements, Se is of prime importance as it is part of the active site in selenoproteins. European soil and plants are relatively poor sources of Se, while farm animals are generally supplemented with Se in order to improve their health and avoid deficiency syndromes. We therefore wondered whether German vegetarians display a measurable Se deficiency. To this end, we compared young vegetarians (n 54) and omnivores (n 53). We assessed their Se status by measuring extracellular glutathione peroxidase 3 (GPX3) activity, and concentrations of total serum Se and circulating Se-transport protein selenoprotein P (SEPP). GPX3 activities were not different between the groups, whereas both total Se and SEPP concentrations were reduced to 79·5 and 71·2 % in vegetarians compared with omnivores. When splitting the group of vegetarians into vegans (n 26) and vegetarians consuming egg and milk products (n 28), analyses of the Se-dependent biomarkers did not reveal significant differences. We conclude that low serum Se is mirrored by circulating SEPP concentrations, but not by GPX3 activities in marginally supplied individuals. The specific dietary Se sources, divergent metabolic routes of selenomethionine v. selenocysteine and the different saturation kinetics of GPX3 and SEPP probably underlie our contradictory findings. Whether German vegetarians and vegans need to be considered as a Se-deficient group depends on the biomarker chosen.

During exercise, ammonia levels are related to the appearance of both central and peripheral fatigue. Therefore, controlling the increase in ammonia levels is an important strategy in ameliorating the metabolic response to exercise and in improving athletic performance. Free amino acids can be used as substrates for ATP synthesis that produces ammonia as a side product. Keto analogues act in an opposite way, being used to synthesise amino acids whilst decreasing free ammonia in the blood. Adult male rats were divided into four groups based on receiving either keto analogues associated with amino acids (KAAA) or a placebo and resistance exercise or no exercise. There was an approximately 40 % increase in ammonaemia due to KAAA supplementation in resting animals. Exercise increased ammonia levels twofold with respect to the control, with a smaller increase (about 20 %) in ammonia levels due to exercise. Exercise itself causes a significant increase in blood urea levels (17 %). However, KAAA reduced blood urea levels to 75 % of the pre-exercise values. Blood urate levels increased 28 % in the KAAA group, independent of exercise. Supplementation increased glucose levels by 10 % compared with control animals. Exercise did not change glucose levels in either the control or supplemented groups. Exercise promoted a 57 % increase in lactate levels in the control group. Supplementation promoted a twofold exercise-induced increase in blood lactate levels. The present results suggest that an acute supplementation of KAAA can decrease hyperammonaemia induced by exercise.

Certain forms of dietary Se may have an advantage in improving Se status and reducing cancer risk. The present study compared the effects of an Se-enriched milk protein product (dairy-Se) with an Se yeast (yeast-Se) on selenoprotein activity and expression in the mouse colon. Mice were fed four diets for 4 weeks: a control milk protein diet (Se at 0·068 parts per million (ppm)), dairy-Se diets with Se at 0·5 and 1 ppm, and a yeast-Se diet with Se at 1 ppm. Cytosolic glutathione peroxidase-1 (GPx-1) activity, mRNA of selenoprotein P (SeP), GPx-1, gastrointestinal glutathione peroxidase-2 (GPx-2) and thioredoxin reductase-1 (TrxR-1) were examined in the mouse colon. Dairy-Se diets did not significantly affect GPx-1 mRNA and GPx-1 activity but produced a dose-dependent increase in SeP and GPx-2 mRNA, with a significantly higher level achieved at 1 ppm Se (P < 0·05). Yeast-Se at 1 ppm significantly increased GPx-1 mRNA and GPx-1 activity (P < 0·01) but not GPx-2 mRNA. Neither Se supplement had any effect on TrxR-1. The present study indicates that selenoprotein levels in the mouse colon are regulated differently depending on the Se supplement. As we have previously shown that dairy-Se at 1 ppm was protective against colorectal cancer (CRC) in an azoxymethane-induced CRC mouse model, this up-regulation of colonic GPx-2 and SeP with Se supplementation may be crucial to its chemopreventive action.

We have demonstrated previously that Asn-Pro-Trp-Asp-Gln (NPWDQ, amino acids 107–111 of αs2-casein) inhibited allergen permeation, such as that demonstrated by ovalbumin, using Caco-2 cells as an in vitro human intestinal epithelial model and in mouse jejunal and ileal loops ex vivo. In the present study, the mechanism underlying this inhibitory activity was examined in Caco-2 cells. Transepithelial resistance value increased in response to the addition of increasing NPWDQ concentrations (10− 6–10− 4 m), which suggests that this peptide enhanced epithelial barrier function. Next, changes in mRNA expression by the addition of NPWDQ (10− 6 m) were analysed in Caco-2 cells using the microarray method. NPWDQ up-regulated the expression of the occludin gene in cells, but the level of the genes of the claudin family and zonula occludens-1 (ZO-1) was unchanged. Increased protein expression of occludin, but not of claudin-1 or of ZO-1, was also observed. Therefore, it is suggested that NPWDQ up-regulated the expression of occludin in particular and enforced the tight junction barrier. These data imply that a food-derived peptide can fine-tune the epithelial barrier.

Alkylresorcinols (AR) in plasma samples have been suggested to be short- to medium-term biomarkers of whole grain wheat and rye intake. In the present study, we investigated whether AR are present in human adipose tissues, and if content correlated with long-term whole grain bread intake. Furthermore, we investigated if the relative AR homologue composition reflected what has been found previously in the habitual diet of Swedes. Biopsy samples (10–25 mg) from free-living Swedish women (n 20) were analysed by GC–MS. The mean total AR concentration in the samples was 0·54 (sd 0·35) μg/g, ranging from below limit of quantification ( < 0·08 μg/g) to 1·50 μg/g. Whole grain bread intake was significantly correlated with plasma total AR content (r 0·48, P < 0·05), and the C17 : 0/C21 : 0 ratio was 0·35 (sd 0·24), which is similar to what is found in plasma among free-living subjects consuming a mixed whole grain wheat and rye diet. These results suggest that AR in the adipose tissue should be evaluated as a long-term biomarker of whole grain wheat and rye intake.

The pathological mechanism of restenosis is primarily attributed to excessive proliferation of vascular smooth muscle cells (VSMC). The preventive effects of ethanol extract of Dunaliella salina (EDS) on balloon injury-induced neointimal formation were investigated. To explore its molecular mechanism in regulating cell proliferation, we first showed that EDS markedly reduced the human aortic smooth muscle cell proliferation via the inhibition of 5′-bromo-2′-deoxyuridine (BrdU) incorporation at 40 and 80 μg/ml. This was further supported by the G0/G1-phase arrest using a flow cytometric analysis. In an in vivo study, EDS at 40 and 80 μg/ml was previously administered to the Sprague–Dawley rats and found that the thickness of neointima, and the ratio of neointima:media were also reduced. EDS inhibited VSMC proliferation in a dose-dependent manner following stimulation of VSMC cultures with 15 % fetal bovine serum (FBS). Suppressed by EDS were 15 % FBS-stimulated intracellular Raf, phosphorylated extracellular signal-regulated kinases (p-Erk) involved in cell-cycle arrest and proliferating cell nuclear antigen. Phosphorylated focal adhesion kinase (p-FAK) was also suppressed by EDS. Also active caspase-9, caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) protein expression levels were increased by administration with EDS; the apoptotic pathway may play an important role in the regulatory effects of EDS on cell growth. These observations provide a mechanism of EDS in attenuating cell proliferation, thus as a potential intervention for restenosis.

Dietary intake of isothiocyanates (ITC) has been associated with reduced cancer risk. The dietary phenethyl ITC (PEITC) has previously been shown to decrease the phosphorylation of the translation regulator 4E binding protein 1 (4E-BP1). Decreased 4E-BP1 phosphorylation has been linked to the inhibition of cancer cell survival and decreased activity of the transcription factor hypoxia-inducible factor (HIF), a key positive regulator of angiogenesis, and may therefore contribute to potential anti-cancer effects of PEITC. In the present study, we have investigated the in vitro and in vivo effects of watercress, which is a rich source of PEITC. We first demonstrated that, similar to PEITC, crude watercress extracts inhibited cancer cell growth and HIF activity in vitro. To examine the effects of dietary intake of watercress, we obtained plasma and peripheral blood mononuclear cells following the ingestion of an 80 g portion of watercress from healthy participants who had previously been treated for breast cancer. Analysis of PEITC in plasma samples from nine participants demonstrated a mean maximum plasma concentration of 297 nm following the ingestion of watercress. Flow cytometric analysis of 4E-BP1 phosphorylation in peripheral blood cells from four participants demonstrated significantly reduced 4E-BP1 phosphorylation at 6 and 8 h following the ingestion of watercress. Although further investigations with larger numbers of participants are required to confirm these findings, this pilot study suggests that flow cytometry may be a suitable approach to measure changes in 4E-BP1 phosphorylation following the ingestion of watercress, and that dietary intake of watercress may be sufficient to modulate this potential anti-cancer pathway.

During pregnancy, growth of the foetus depends on an adequate glycine supply because it is needed for synthesis of fetal DNA, collagen and serine. Since pregnant adolescent girls give birth to lower birth weight babies, it is possible that they do not produce sufficient glycine to meet overall demands as their adult counterparts, especially after an overnight fast. The objective of the study was to measure and compare the flux of glycine among adolescents and adult women in the first and third trimesters of pregnancy. Glycine flux was measured by continuous intravenous infusion of 2H2-glycine in eight overnight fasted adolescents and in eight adult women in the first and third trimesters of pregnancy. There was a significant interaction between subject's age and time of pregnancy (P = 0·02), as weight-specific glycine flux decreased by 39 % from trimesters 1 to 3 in the adolescents but increased by approximately 5 % in the adults. Whole body glycine flux also decreased significantly in the adolescent group (P < 0·05) from trimesters 1 to 3, and this was associated with a significant reduction in plasma glycine concentration. In trimester 3, there was a positive correlation between glycine flux and the subject's age indicating that younger subjects had slower fluxes. These findings suggest that after a brief period of food deprivation, the pregnant adolescent cannot maintain glycine production as her adult counterpart in late pregnancy. It is possible that this inability to maintain endogenous glycine production makes her foetus more vulnerable to impaired growth if food deprivation becomes more frequent or is prolonged.

Nutritional genomics has reached the public through applications of the Human Genome Project offered direct to consumers (DTC). The ability to pursue nutrigenetic testing without the involvement of a health care professional has received considerable attention from academic and policy commentators. To better understand the knowledge and attitudes of Canadian health care professionals regarding nutritional genomics and nutrigenetic testing, qualitative research in the form of focus group discussions was undertaken. Four key themes emerged: (1) concerns over DTC testing; (2) lack of health care professional competency; (3) genetic scepticism and inevitability; (4) expectation of regulation. Together, they indicate that health care professionals have little knowledge about nutritional genomics and hold contradictory attitudes towards genomics in general, and to nutritional genomics in particular. Respondents argue in favour of a delivery model where health care professionals act as intermediaries. They are also aware of their lack of competency to provide such services. To ensure greater public protection, respondents cite the importance of more stringent regulatory oversight of DTC genetic testing. Whether such an approach is necessary to address the various ethical and social issues raised by nutrigenetic testing remains an open debate.

The aim of the present study was to investigate the direct action of the phyto-oestrogen genistein (Gen) on vascular endothelial behaviour, either in the presence or absence of proinflammatory agents. In rat aortic endothelial cell (EC) cultures, 24 h of treatment with Gen significantly increased cell proliferation in a wide range of concentration (0·001–10 nm). This mitogenic action was prevented by the oestrogen receptor (ER) antagonist ICI 182780 or by the presence of the specific NO synthase inhibitor l-nitro-arginine methyl ester. When monocytes adhesion to EC was measured, Gen partially attenuated leucocyte adhesion not only under basal conditions, but also in the presence of bacterial lipopolysaccharides (LPS). The effect of the phyto-oestrogen on the expression of EC adhesion molecules was evaluated. Gen down-regulated the enhancement in mRNA levels of E-selectin, vascular cell adhesion molecule-1 and P-selectin elicited by the proinflammatory agent bacterial LPS. The regulation of EC programmed death induced by the isoflavone was also demonstrated. Incubation with 10 nm Gen prevented DNA fragmentation induced by the apoptosis inductor H2O2. The results presented suggest that Gen would exert a protective effect on vascular endothelium, due to its regulatory action on endothelial proliferation, apoptosis and leucocyte adhesion, events that play a critical role in vascular diseases. The molecular mechanism displayed by the phyto-oestrogen involved the participation of the ER and the activation of the NO pathway.

The objective of the present study was to evaluate the effect of Lactobacillus acidophilus 4356 on cholesterol metabolism in vivo. Rats were fed a cholesterol-enriched experimental diet with or without L. acidophilus 4356 supplementation at a dose of 109 colony-forming units per d. L. acidophilus 4356 feeding significantly lowered total serum cholesterol, LDL-cholesterol and TAG concentrations, but there was no change in the serum HDL-cholesterol concentrations. In addition, total liver cholesterol and TAG were decreased in the L. acidophilus 4356-fed group. The expression of Niemann-Pick C1-Like 1 (NPC1L1) in the duodenum and jejunum was significantly decreased following L. acidophilus 4356 feeding. Lactobacillus acidophilus 4356 increased the population of lactobacilli and bifidobacteria in the small intestine and faeces compared with the control. These results indicate that the probiotic potential of the L. acidophilus 4356 strain in the control of cholesterol is at least partially mediated by the down-regulation of NPC1L1. Furthermore, these results also potentially suggest a new mechanism that is responsible for the cholesterol-reducing effects of probiotics.

Previous studies have reported the anti-inflammatory properties of pomegranate extracts, suggesting that ellagitannins (ET) and ellagic acid (EA) are the main anti-inflammatory compounds. However, both ET and EA are metabolised in vivo by the gut microbiota to yield urolithins (Uro) which can be found in the gut and in systemic bloodstream. The present study was carried out to evaluate the individual effect of EA and their microbiota-derived metabolites Uro on colon fibroblasts upon IL-1β treatment as an in vitro inflammation model. Uro-A and Uro-B (10 μm) inhibited PGE2 production (85 and 40 %, respectively) after IL-1β stimulation, whereas EA did not show any effect. Uro-A, but not Uro-B, down-regulated cyclo-oxygenase-2 (COX-2) and microsomal PGE synthase-1 (mPGES-1) mRNA expression and protein levels. Both Uro inhibited NF-κB translocation to nucleus. Slight but significant effects were found in the activation of mitogen-activated protein kinase (MAPK) pathways. Uro-A lowered c-Jun N-terminal kinase phosphorylation state, and both Uro inhibited p38 activation. No metabolites derived from Uro or EA were found in the cell media upon incubation of EA or Uro with the cells, and only traces of the compounds were found inside the cells. The present results suggest that Uro, mainly Uro-A, are the main compounds that are responsible for the pomegranate anti-inflammatory properties. The mechanism of action implicated seems to be via the inhibition of activation of NF-κB and MAPK, down-regulation of COX-2 and mPGES-1 expressions, and consequently,via the reduction of PGE2 production. Taking into account that Uro did not enter the cells, a competitive binding for IL-1β membrane receptor cannot be discarded.