Rye bread improves bowel function and decreases the concentrations of some compounds that are putative colon cancer risk markers in middle-aged women and men

Eating away cancer: the potential of diet and the microbiome for shaping immunotherapy outcome

The gut microbiome (GMB) plays a substantial role in human health and disease. From affecting gut barrier integrity to promoting immune cell differentiation, the GMB is capable of shaping host immunity and thus oncogenesis and anti-cancer therapeutic response, particularly with immunotherapy. Dietary patterns and components are key determinants of GMB composition, supporting the investigation of the diet-microbiome-immunity axis as a potential avenue to enhance immunotherapy response in cancer patients. As such, this review will discuss the role of the GMB and diet on anti-cancer immunity. We demonstrate that diet affects anti-cancer immunity through both GMB-independent and GMB-mediated mechanisms, and that different diet patterns mold the GMB's functional and taxonomic composition in distinctive ways. Dietary modulation therefore shows promise as an intervention for improving cancer outcome; however, further and more extensive research in human cancer populations is needed.

Effects of Wholegrain Compared to Refined Grain Intake on Cardiometabolic Risk Markers, Gut Microbiota, and Gastrointestinal Symptoms in Children: A Randomized Crossover Trial

BACKGROUND

Wholegrain intake is associated with lower risk of cardiometabolic diseases in adults, potentially via changes in the gut microbiota. Although cardiometabolic prevention should start early, we lack evidence on the effects in children.

OBJECTIVES

This study investigated the effects of wholegrain oats and rye intake on serum low-density lipoprotein (LDL) cholesterol and plasma insulin (coprimary outcomes), other cardiometabolic markers, body composition, gut microbiota composition and metabolites, and gastrointestinal symptoms in children with high body mass index (BMI).

METHODS

In a randomized crossover trial, 55 healthy Danish 8- to 13-y-olds received wholegrain oats and rye ("WG") or refined grain ("RG") products ad libitum for 8 wk in random order. At 0, 8, and 16 wk, we measured anthropometry, body composition by dual-energy absorptiometry, and blood pressure. Fasting blood and fecal samples were collected for analysis of blood lipids, glucose homeostasis markers, gut microbiota, and short-chain fatty acids. Gut symptoms and stool characteristics were determined by questionnaires. Diet was assessed by 4-d dietary records and compliance by plasma alkylresorcinols (ARs).

RESULTS

Fifty-two children (95%) with a BMI z-score of 1.5 ± 0.6 (mean ± standard deviation) completed the study. They consumed 108 ± 38 and 3 ± 2 g/d wholegrain in the WG and RG period, which was verified by a profound difference in ARs (P < 0.001). Compared with RG, WG reduced LDL cholesterol by 0.14 (95% confidence interval: -0.24, -0.04) mmol/L (P = 0.009) and reduced total:high-density lipoprotein cholesterol (P < 0.001) and triacylglycerol (P = 0.048) without altering body composition or other cardiometabolic markers. WG also modulated the abundance of specific bacterial taxa, increased plasma acetate, propionate, and butyrate and fecal butyrate and reduced fatigue with no other effects on gut symptoms.

CONCLUSION

High intake of wholegrain oats and rye reduced LDL cholesterol and triacylglycerol, modulated bacterial taxa, and increased beneficial metabolites in children. This supports recommendations of exchanging refined grain with wholegrain oats and rye among children. This trial was registered at clinicaltrials.gov as NCT04430465.

Chemopreventive Effect of an In Vitro Digested and Fermented Plant Sterol-Enriched Wholemeal Rye Bread in Colon Cancer Cells

Diet is crucial for the prevention of colorectal cancer. Whole grains are the source of beneficial compounds for this, such as fiber. The enrichment of wholemeal rye bread with plant sterols (PSs) could increase its beneficial effects. This study aimed to assess the potential antiproliferative effect of this enriched food on colon adenocarcinoma cells (Caco-2) compared with a non-enriched one. After a human oral chewing, simulated semi-dynamic gastrointestinal digestion and colonic fermentation in a simgi® system, fermentation liquids (FLs) obtained were used as treatment for cells. Cytotoxicity assay showed that samples diluted 1/5 (v/v) with DMEM are not toxic for non-tumoral cells, whereas they damage tumoral cells. Samples with PS (FLPS) produced a higher chemopreventive effect (vs. blank) in MTT and apoptosis assays, as well as higher gene expression of TP53 and Casp8. Nevertheless, FL0 (without PS) produced a higher chemopreventive effect in a cell cycle and reduced glutathione and calcium assays, besides producing higher gene expression of Casp3 and lower CCND1. The distinct antiproliferative effect of both FLs is attributed to differences in PSs, short chain fatty acids (lower concentration in FLPS vs. FL0) and antioxidant compounds. These results may support wholemeal rye bread consumption as a way of reducing the risk of colorectal cancer development, although further research would be needed.

Interaction between β-glucans and gut microbiota: a comprehensive review

Gut microbiota (GMB) in humans plays a crucial role in health and diseases. Diet can regulate the composition and function of GMB which are associated with different human diseases. Dietary fibers can induce different health benefits through stimulation of beneficial GMB. β-glucans (BGs) as dietary fibers have gained much interest due to their various functional properties. They can have therapeutic roles on gut health based on modulation of GMB, intestinal fermentation, production of different metabolites, and so on. There is an increasing interest in food industries in commercial application of BG as a bioactive substance into food formulations. The aim of this review is considering the metabolizing of BGs by GMB, effects of BGs on the variation of GMB population, influence of BGs on the gut infections, prebiotic effects of BGs in the gut, in vivo and in vitro fermentation of BGs and effects of processing on BG fermentability.

Are Sugar-Reduced and Whole Grain Infant Cereals Sensorially Accepted at Weaning? A Randomized Controlled Cross-Over Trial

The way infants are fed during the complementary period can have a significant impact on infants' health and development. Infant cereals play an important role in complementary feeding in many countries. In spite of well documented benefits of a low sugar and high whole grain diet, commercial infant cereals are often refined and contain a high amount of sugars. The aim of the present study was to compare the sensory acceptability, gastrointestinal tolerance and bowel habits of two commercially available infant cereals in Spain with varying sugar and whole grain contents in infants at weaning. Forty-six healthy infants (mean age = 5.2 ± 0.4 months) received one of the two infant cereals containing either 0% whole grain flour and a high sugar content produced by starch hydrolysis (24 g/100 g) (Cereal A) or 50% whole grain flour and a medium-sugar content produced by hydrolysis (12 g/100 g) (Cereal B) in a randomized, triple blind, cross-over controlled trial. Both types of infant cereals were consumed for seven weeks. The cross-over was carried out after seven weeks. Sensory acceptability, anthropometry, gastrointestinal tolerance and adverse events were measured, and results evaluated using a linear regression model. No significant differences were observed between groups in any of the main variables analyzed. Importantly, the long-term health implications of our findings represent a wake-up call for the food industry to reduce or even eliminate simple sugars in infant cereals and for regulatory bodies and professional organizations to recommend whole grain infant cereals.

Effects of rice-based and wheat-based diets on bowel movements in young Korean women with functional constipation

Background

Although several studies have reported the effects that dietary fiber intake from different types of grains and fiber components have on bowel movements, insufficient attention has been paid to comparing and evaluating the effects of rice-based and wheat-based diets. This study compared and evaluated the effects of ingesting rice-based (brown rice-based diet: BRD; white rice-based diet: WRD) and wheat-based diet (WD) on the bowel movements of young women with functional constipation.

Method

Based on an open, randomized, controlled, and parallel design, 39 subjects were assigned to BRD, WRD, and WD groups (13 in each group). Each participant had received three types of experimental diets over the course of 4 weeks and we recommended that the subjects eat only the test diet provided during the study. Primary outcomes (total colon transit time TCTT) and secondary outcomes (bowel movements, short-chain fatty acid content, and fecal enzyme activity) were compared before and after the 4-week intervention period.

Results

After the 4-week study, the rice-based diet (BRD and WRD) groups and the WD group had a statistically significant difference in TCTT (p = 0.028). The TCTT of the BRD group was significantly reduced (p = 0.028) compared with the WRD group (−16.5 ± 8.1 vs +6.8 ± 2.1), and the TCTT of the WD group was also significantly reduced (p = 0.022) compared with that of the WRD group (−17.1 ± 11.9 vs +6.8 ± 2.1).

Conclusion

Among women with functional constipation, the BRD and WD both improved bowel function by reducing TCTT and increasing the number of bowel movements compared with the WRD group.

The Effects of Intact Cereal Grain Fibers, Including Wheat Bran on the Gut Microbiota Composition of Healthy Adults: A Systematic Review

The human microbiota is increasingly recognized as a major factor influencing health and well-being, with potential benefits as diverse as improved immunity, reduced risk of obesity, Type 2 diabetes, and improved cognition and mood. Bacteria inhabiting the gut are dependent on the provision of fermentable dietary substrates making diet a major factor driving the composition of the human gut microbiota. Dietary fiber may modify microbiota abundance, diversity, and metabolism including short-chain fatty acid production. The majority of research to date has explored isolated fibers, and the influence of habitual fiber consumption is less well-established. The aim of the current article was to systematically review evidence from human intervention studies for the effects of intact cereal fibers, and their active sub-fractions, on gut microbiota composition in healthy adults. Studies published in the past 20 years were identified through the PubMed and Cochrane electronic databases. Inclusion criteria were: healthy adult participants (>18 years), inclusion of at least one intact cereal fiber, or its sub-fraction, and measurement of fecal microbiota related outcomes. As every individual has a unique microbiota many trials utilized a cross-over design where individuals acted as their own control. Outcome measures included change to the microbiota, species diversity, or species abundance, or metabolic indicators of microbiota fermentation such as short chain fatty acids or fecal nitrogen. Two hundred and twenty three publications were identified and 40 included in the final review. In discussing the findings, particular attention has been paid to the effects of wheat fiber, bran, and arabinoxylans (AXOS) as this is the dominant source of fiber in many Western countries. Thirty-nine of the forty-two studies demonstrated an increase in microbiota diversity and/or abundance following intact cereal fiber consumption, with effects apparent from 24 h to 52 weeks. Increases in wheat fiber as low as 6–8 g were sufficient to generate significant effects. Study duration ranged from 1 day to 12 weeks, with a single study over 1 year, and exploration of the stability of the microbiota following long-term dietary change is required. Increasing cereal fiber consumption should be encouraged for overall good health and for gut microbiota diversity.

Whole-Grain Rye and Wheat Affect Some Markers of Gut Health without Altering the Fecal Microbiota in Healthy Overweight Adults: A 6-Week Randomized Trial

Background: Whole grains have shown potential for improving gut health, but evidence comparing different whole-grain types is lacking.Objective: We investigated whether whole-grain wheat (WGW) and whole-grain rye (WGR) improve gut health in different ways compared to refined wheat (RW), with the primary outcomes of microbiota composition and gastrointestinal (GI) symptoms.Methods: In a randomized parallel trial, 70 healthy adults (in means ± SDs; aged 51.0 ± 9.4 y, body mass index [BMI (in kg/m²)] 27.8 ± 1.9, 32:38 men:women) replaced cereal foods from their habitual diet with WGR, WGW, or RW (control). Before and after a 6-wk intervention, a spot stool sample was collected and analyzed for short-chain fatty acids and microbiota composition through the use of 16S ribosomal RNA gene-targeted high-throughput amplicon sequencing. GI symptoms and stool regularity were evaluated by questionnaires at baseline and after weeks 2, 4, and 6.Results: Intakes of whole grains were 145.2 ± 75.9, 124.2 ± 57.3, and 5.4 ± 3.2 g/d in the WGW, WGR, and RW groups, respectively. Gut microbiota composition was not affected by diet. The relative change in fecal butyrate decreased in the RW (-38%) group compared to the WGW (25%, P = 0.014) and WGR groups (-1%, P = 0.037). Other short-chain fatty acids were unaffected. Flatulence was more frequent following intake of WGW (OR: 2.06, 95% CI: 1.03, 4.17) and WGR (OR: 2.62, 95% CI: 1.35, 5.22) compared to RW, whereas bloating was less frequent following WGW (OR: 0.38, 95% CI: 0.18, 0.80) and WGR (OR: 0.34, 95% CI: 0.16, 0.72). Stool frequency increased following WGR but not WGW, compared to RW in weeks 2 (0.4 defecations/d, P = 0.049) and 4 (0.5 defecations/d, P = 0.043), but not in week 6. The WGW and WGR groups did not differ from each other in any of the variables tested.Conclusion: Regular consumption of WGR and WGW affected fecal butyrate concentration and gastrointestinal symptoms in healthy overweight adults, supporting the hypothesis that WGR and WGW can be included in the diet equally to maintain gut health. This trial was registered at clinicaltrials.gov as NCT02358122.

An improved course of glycaemia after a bread based breakfast is associated with beneficial effects on acute and semi-acute markers of appetite

A breakfast giving low and sustained glycaemia results in beneficial effects on appetite, both acute and after a subsequentad libmeal.

Adherence to the healthy Nordic food index, dietary composition, and lifestyle among Swedish women

Background

Studies examining diet scores in relation to health outcomes are gaining ground. Thus, control for dietary factors not part of the score, and lifestyle associated with adherence, is required to allow for a causal interpretation of studies on diet scores and health outcomes.

Objective

The study objective is to describe and investigate dietary composition, micronutrient density, lifestyle, socioeconomic factors, and adherence to the Nordic Nutrition Recommendations across groups defined by their level of adherence to a healthy Nordic food index (HNFI). The paper examines both dietary components included in the HNFI as well as dietary components, which are not part of the HNFI, to get a broad picture of the diet.

Design

The study is cross-sectional and conducted in the Swedish Women's Lifestyle and Health cohort. We included 45,277 women, aged 29–49 years at baseline (1991–1992). The HNFI was defined by six items: wholegrain bread, oatmeal, apples/pears, cabbages, root vegetables and fish/shellfish, using data from a food frequency questionnaire. Proportions, means and standard deviations were calculated in the entire cohort and by adherence groups.

Results

Women scoring high on the HNFI had a higher energy intake, compared to low adherers. They had a higher intake of fiber and a higher micronutrient density (components of the HNFI), but also a higher intake of items not included in the HNFI: red/processed meats, sweets, and potatoes. They were on average more physically active and less likely to smoke.

Conclusions

Adherence to the HNFI was associated with a generally healthier lifestyle and a high intake of health-beneficial components. However, it was also associated with a higher energy intake and a higher intake of foods without proven health benefits. Therefore, future studies on the HNFI and health outcomes should take into account potential confounding of dietary and lifestyle factors associated with the HNFI.

Consumption of predefined 'Nordic' dietary items in ten European countries - an investigation in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

OBJECTIVE

Health-beneficial effects of adhering to a healthy Nordic diet index have been suggested. However, it has not been examined to what extent the included dietary components are exclusively related to the Nordic countries or if they are part of other European diets as well, suggesting a broader preventive potential. The present study describes the intake of seven a priori defined healthy food items (apples/pears, berries, cabbages, dark bread, shellfish, fish and root vegetables) across ten countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) and examines their consumption across Europe.

DESIGN

Cross-sectional study. A 24 h dietary recall was administered through a software program containing country-specific recipes. Sex-specific mean food intake was calculated for each centre/country, as well as percentage of overall food groups consumed as healthy Nordic food items. All analyses were weighted by day and season of data collection.

SETTING

Multi-centre, European study.

SUBJECTS

Persons (n 36 970) aged 35-74 years, constituting a random sample of 519 978 EPIC participants.

RESULTS

The highest intakes of the included diet components were: cabbages and berries in Central Europe; apples/pears in Southern Europe; dark bread in Norway, Denmark and Greece; fish in Southern and Northern countries; shellfish in Spain; and root vegetables in Northern and Central Europe. Large inter-centre variation, however, existed in some countries.

CONCLUSIONS

Dark bread, root vegetables and fish are strongly related to a Nordic dietary tradition. Apples/pears, berries, cabbages, fish, shellfish and root vegetables are broadly consumed in Europe, and may thus be included in regional public health campaigns.

Postprandial glucose metabolism and SCFA after consuming wholegrain rye bread and wheat bread enriched with bioprocessed rye bran in individuals with mild gastrointestinal symptoms

Background

Rye bread benefits glucose metabolism. It is unknown whether the same effect is achieved by rye bran-enriched wheat bread. We tested whether white wheat bread enriched with bioprocessed rye bran (BRB + WW) and sourdough wholegrain rye bread (WGR) have similar effects on glucose metabolism and plasma level of short chain fatty acids (SCFAs).

Methods

Twenty-one (12 women) of 23 recruited subjects completed an intervention with a four-week run-in and two four-week test periods in cross-over design. White wheat bread (WW; 3% fibre) was consumed during the run-in, and WGR and BRB + WW (10% fibre) during the test periods. A meal test providing 51/33/11 E % from carbohydrates/fat/protein was conducted at the end of each period. Fasting and postprandial plasma samples were analysed for glucose, insulin, and SCFA.

Results

Glucose and insulin responses and plasma concentrations of SCFAs to the meal test were similar between the WGR and BRB + WW periods. When compared to the WW period, postprandial insulin concentration at 120 min was lower (p = 0.023) and the first-phase insulin secretion improved (p = 0.033) only after the WGR period, whereas postprandial concentrations of butyrate (p < 0.05) and propionate (p = 0.009) at 30 min increased during both rye bread periods.

Conclusions

Beneficial effects of WGR over white wheat bread on glucose and SCFA production were confirmed. The enrichment of the white wheat bread with bioprocessed rye bran (BRB + WW) yielded similar but not as pronounced effects than WGR when compared to WW alone. Postprandially measured glucose metabolism and concentrations of SCFAs provided additional information along with fasting measurements.

Colorectal cancer risk factors among the population of South-East Siberia: a case-control study

Colorectal cancer remains one of the most widespread malignancies in the world. However, there is a lack of comprehensive studies considering colorectal cancer risk factors among Russian populations, particularly in Siberia. The aim of this investigation was to determine the impact of various lifestyle, dietary, family, and socioeconomical factors on colorectal cancer risk in South-East Siberia. We recruited 185 Russian colorectal cancer cases and 210 gender-, age-, and ethnicity-matched asymptomatic controls with no history of any malignant tumor, using a specially designed questionnaire to obtain relevant information. After the statistical analysis, we defined several significant factors affecting colorectal cancer risk. Among these were smoking (OR=2.13, 95%CI=1.4- 3.24, P=0.0004), being overweight (BMI between 25-30, OR=2.45, 95%CI=1.49-4.03, P=0.0004), alcohol drinking (OR=8.73, 95%CI=5.49-13.87, P<0.0001), beer drinking (OR=9.24, 95%CI=5.14-16.61, P<0.0001), consumption of hard liquor (OR=9.37, 95%CI=5.92-14.82, P<0.0001), excessive red meat consumption (P<0.0001), excessive intake of red meat products (P<0.0001), excessive intake of dairy products (P<0.0001), excessive sour cream and cheese consumption (P<0.0001 and 0.0002, respectively), spicy food consumption (OR=2.87, 95%CI=1.9-4.33, P<0.0001), family history of gastrointestinal malignant tumors (OR=3.99, 95%CI=2.09-7.59, P<0.0001), and income exceeding twice the subsistence minimum (OR=5.34, 95%CI=3.35-8.53, P<0.0001). Certain factors, such as high concentration of salt in the food and precancerous colonic lesions, demonstrated borderline significance (OR=3.45, 95%CI=1.68-7.1, P=0.0008, and OR=5.25, 95%CI=1.94-14.22, P=0.001, respectively). Some factors were established as protective, like consumption of rye bread and both rye and wheat bread (OR=0.32, 95%CI=0.21-0.5, P<0,0001, and OR=0.07, 95%CI=0.02-0.21, P<0.0001, respectively), and also low concentration of salt in the food, although this was of borderline significance (OR=0.43, 95%CI=0.26-0.69, P=0.0006). ABO and Rhesus blood antigens were not associated with increased colorectal cancer risk. These results should be definitely applied for elaboration of programs of colorectal cancer prevention in Russia, particularly in Siberia.

The role of gut microbiota in the pathogenesis of colorectal cancer

The human gastrointestinal tract harbors a complex and abundant microbial community that can reach levels as high as 10(13)-10(14) microorganisms in the colon. These microorganisms are essential to a host's well-being in terms of nutrition and mucosa immunity. However, numerous studies have also implicated members of the colonic microbiota in the development of colorectal cancer (CRC). While CRC involves a genetic component where damaged DNA and genetic instability initiates a malignant transformation, environmental factors can also contribute to the onset of CRC. Furthermore, considering the constant exposure of the colonic mucosa to the microbiome and/or its metabolites, the mucosa has long been proposed to contribute to colon tumorigenesis. However, the mechanistic details of these associations remain unknown. Fortunately, due to technical and conceptual advances, progress in characterizing the taxonomic composition, metabolic capacity, and immunomodulatory activity of human gut microbiota have been made, thereby elucidating its role in human health and disease. Furthermore, the use of experimental animal models and clinical/epidemiological studies of environmental etiological factors has identified a correlation between gut microbiota composition and gastrointestinal cancers. Bacteria continuously stimulate activated immunity in the gut mucosa and also contribute to the metabolism of bile and food components. However, the highest levels of carcinogen production are also associated with gut anaerobic bacteria and can be lowered with live lactobacilli supplements. In this review, evidence regarding the relationship between microbiota and the development of CRC will be discussed, as well as the role for microbial manipulation in affecting disease development.

Plasma and urine concentrations of bioactive dietary benzoxazinoids and their glucuronidated conjugates in rats fed a rye bread-based diet

Thorough knowledge of the absorption and metabolism of dietary benzoxazinoids is needed to understand their health-promoting effects. In this study, the fates of these bioactive compounds were examined by LC-MS/MS in plasma, urine, and feces after ingesting a daily dose of 4780 ± 68 nmol benzoxazinoids from rye bread using Wistar rats as a model. HBOA-glc (2-β-D-glucopyranosyloxy-1,4-benzoxazin-3-one) was the predominant benzoxazinoid in the plasma (74 ± 27 nmol/L), followed by DIBOA-glc (2-β-D-glucopyranosyloxy-4-hydroxy-1,4-benzoxazin-3-one) and HBOA. The total level of benzoxazinoids in the urine was 1176 ± 66 nmol/d, which corresponds to approximately 25% of the total dietary intake. The urinary benzoxazinoid profile differed from that of plasma with HBOA-glc and DIBOA-glc (647 ± 31 and 466 ± 33 nmol/d, respectively) as the major urinary components. The glucuronide conjugates of HBOA and DIBOA were detected in both the plasma and urine. N-dehydroxylation was found to be a critical step in the absorption of hydroxamic acids. This unprecedented study will trigger future interest in the biological effects of benzoxazinoids in whole grain rye and wheat diets in humans and other animals.

Depolymerization degree of water-extractable arabinoxylans in rye bread: characteristics of inbred lines used for breeding of bread cultivars

The water-extractable arabinoxylans (WE AXs) present in rye bread govern its viscous properties, which may be related to reduced risk of cardiovascular diseases and diabetes. Breads made from rye cultivars generally exhibit higher AX-dependent extract viscosities (Cyran, M. R.; Saulnier, L. Food Chemistry2012, 131, 667-676) when compared with those produced from inbred lines used for their breeding. To give further details about this trend, the WE AXs were isolated from breads of lines and structurally characterized by HPSEC and (1)H NMR spectroscopy. The extract viscosities of endosperm and whole-meal breads were usually comparable, in contrast to those made from rye cultivars with higher viscosity of endosperm bread. The WE AXs present in breads obtained from inbred lines were characterized by the higher degradation degrees than those in breads from cultivars, as indicated by their HPSEC-RI profiles. This was associated with considerably lower proportions of 2-Xylp in their backbones. Besides, a level of endoxylanase activity in flours from inbred lines was much higher than that in flours from cultivars. Breeding of hybrid rye cultivars for production of high-viscosity bread requires the proper components. They may be preliminarily selected from populations with high WE AX contents and relatively low levels of endoxylanase activity by using the overall viscosity test for starting flours. However, further measurement of AX-dependent extract viscosity in test breads made from such lines may verify their usefulness completely.

Recent developments on new formulations based on nutrient-dense ingredients for the production of healthy-functional bread: a review

Bread is one of the oldest functional foods which its health effects have been investigated in many studies. The current communication presents a review of published studies in recent years on the topic and looks at possible future trends in the improved nutritional and health qualities which have been applied in the bakery industry, directing it further to the formulation design and production of functional breads. The results show that many beneficial ingredients such as dietary fibers, phenolic antioxidants, marine ingredients, and n-3 fatty acids can be used in the bread industry to increase its functionality and result in healthy products, low in calories, cholesterol and celiac disease. Moreover, the use of psyllium seed, amaranth seed, chestnut flour and prebiotics in gluten-free bread (GFB) baking may be the promising frontier to improve overall appearance, quality, sensory properties, and shelf-life of GFB.

Adherence to a healthy Nordic food index is associated with a lower incidence of colorectal cancer in women: the Diet, Cancer and Health cohort study

Colorectal cancer (CRC) is a multi-factorial disease in which diet is believed to play a role. Little is known about the health effects of specific regional diets. The Nordic diet is high in fat and sugar but also includes a range of traditional products with anticipated health-promoting effects. The aim of this cohort study was to determine whether a healthy Nordic food index consisting of fish, cabbage, rye bread, oatmeal, apples, pears and root vegetables was related to CRC incidence. Data were obtained from a prospective cohort study of 57,053 Danish men and women aged 50-64 years, of whom 1025 developed CRC (13 years' follow-up). Incidence rate ratios (IRR) with 95 % CI were calculated from Cox proportional hazard models. Women who strongly adhered to a healthy Nordic food index had a 35 % lower incidence of CRC than women with poor adherence (adjusted IRR, 0·65; 95 % CI 0·46, 0·94); a similar tendency was found for men. Women had a 9 % lower incidence of CRC per point adherence to the healthy Nordic food index, but no significant effect was found for men. A regional diet based on healthy Nordic food items was therefore associated with a lower incidence of CRC in women. The protective effect was of the same magnitude as previously found for the Mediterranean diet, suggesting that healthy regional diets should be promoted in order to ensure health; this will also preserve cultural heredity and the environment.

Whole grains: benefits and challenges

Inclusion of whole grains (WG) in the diet is recommended in dietary guidance around the world because of their associations with increased health and reduced risk of chronic disease. WGs are linked to reduced risk of obesity or weight gain; reduced risk of cardiovascular disease (CVD), including coronary heart disease (CHD), hypertension, and stroke; improved gut health and decreased risk of cancers of the upper gut; perhaps reduced risk of colorectal cancer; and lower mortality rate. The 2005 United States Dietary Guidelines Advisory Committee has recommended that consumers make "half their grains whole." Yet, whole grains are puzzling both consumers and scientists. Scientists are trying to determine whether their health benefits are due to the synergy of WG components, individual WG components, or the fact that WG eaters make many of the recommended diet and lifestyle choices. Consumers need to understand the WG benefits and how to identify WG foods to have incentive to purchase and use such foods. Industry needs to develop great-tasting, clearly-labeled products. With both these factors working together, it will be possible to change WG consumption habits among consumers.

Functional analysis of colonic bacterial metabolism: relevant to health?

With the use of molecular techniques, numerous studies have evaluated the composition of the intestinal microbiota in health and disease. However, it is of major interest to supplement this with a functional analysis of the microbiota. In this review, the different approaches that have been used to characterize microbial metabolites, yielding information on the functional end products of microbial metabolism, have been summarized. To analyze colonic microbial metabolites, the most conventional way is by application of a hypothesis-driven targeted approach, through quantification of selected metabolites from carbohydrate (e.g., short-chain fatty acids) and protein fermentation (e.g., p-cresol, phenol, ammonia, or H(2)S), secondary bile acids, or colonic enzymes. The application of stable isotope-labeled substrates can provide an elegant solution to study these metabolic pathways in vivo. On the other hand, a top-down approach can be followed by applying metabolite fingerprinting techniques based on (1)H-NMR or mass spectrometric analysis. Quantification of known metabolites and characterization of metabolite patterns in urine, breath, plasma, and fecal samples can reveal new pathways and give insight into physiological regulatory processes of the colonic microbiota. In addition, specific metabolic profiles can function as a diagnostic tool for the identification of several gastrointestinal diseases, such as ulcerative colitis and Crohn's disease. Nevertheless, future research will have to evaluate the relevance of associations between metabolites and different disease states.

Whole grain cereals: functional components and health benefits

Cereal-based food products have been the basis of the human diet since ancient times. Dietary guidelines all over the world are recommending the inclusion of whole grains because of the increasing evidence that whole grains and whole-grain-based products have the ability to enhance health beyond the simple provision of energy and nutrients. In this review we will examine the main chemical components present in whole grains that may have health enhancing properties (dietary fiber, inulin, beta-glucan, resistant starch, carotenoids, phenolics, tocotrienols, and tocopherols) and the role that whole grains may play in disease prevention (cardiovascular diseases and strokes, hypertension, metabolic syndrome, type 2 diabetes mellitus, obesity, as well as different forms of cancer). The knowledge derived from the functional properties of the different chemical components present in whole grains will aid in the formulation and development of new food products with health enhancing characteristics.

Chemopreventive effects of in vitro digested and fermented bread in human colon cells

PURPOSE

Bread as a staple food product represents an important source for dietary fibre consumption. Effects of wheat bread, wholemeal wheat bread and wholemeal rye bread on mechanisms which could have impact on chemoprevention were analysed in colon cells after in vitro fermentation.

METHODS

Effects of fermented bread samples on gene expression, glutathione S-transferase activity and glutathione content, differentiation, growth and apoptosis were investigated using the human colon adenoma cell line LT97. Additionally, apoptosis was studied in normal and tumour colon tissue by determination of caspase activities.

RESULTS

The expression of 76 genes (biotransformation, differentiation, apoptosis) was significantly upregulated (1.5-fold) in LT97 cells. The fermented bread samples were able to significantly increase glutathione S-transferase activity (1.8-fold) and glutathione content (1.4-fold) of the cells. Alkaline phosphatase activity as a marker of differentiation was also significantly enhanced (1.7-fold). The fermented bread samples significantly inhibited LT97 cell growth and increased the level of apoptotic cells (1.8-fold). Only marginal effects on apoptosis in tumour compared to normal tissue were observed.

CONCLUSIONS

This is the first study which presents chemopreventive effects of different breads after in vitro fermentation. In spite of differences in composition, the results were comparable between the bread types. Nevertheless, they indicate a potential involvement of this staple food product regarding the prevention of colon cancer.

Dietary fiber type reflects physiological functionality: comparison of grain fiber, inulin, and polydextrose

Dietary fiber is a nutritional concept based not on physiological functions but on defined chemical and physical properties. Recent definitions of dietary fiber differentiate inherent plant cell wall-associated fiber from isolated or synthetic fiber. For the latter to be defined as fiber, beneficial physiological effects should be demonstrated, such as laxative effects, fermentability, attenuation of blood cholesterol levels, or postprandial glucose response. Grain fibers are a major natural source of dietary fiber worldwide, while inulin, a soluble indigestible fructose polymer isolated from chicory, and polydextrose, a synthetic indigestible glucose polymer, have more simple structures. Inulin and polydextrose show many of the same functionalities of grain fiber in the large intestine, in that they are fermentable, bifidogenic, and laxative. The reported effects on postprandial blood glucose and fasting cholesterol levels have been modest, but grain fibers also show variable effects. New biomarkers are needed to link the physiological functions of specific fibers with long-term health benefits.

A whole-grain cereal-rich diet increases plasma betaine, and tends to decrease total and LDL-cholesterol compared with a refined-grain diet in healthy subjects

Epidemiological studies have repeatedly found that whole-grain (WG) cereal foods reduce the risk of several lifestyle-related diseases, though consistent clinical outcomes and mechanisms are elusive. To compare the effects of a WG-rich diet with a matched refined-grain (RG) diet on plasma biomarkers and bowel health parameters, seventeen healthy subjects (eleven females and six males) completed an exploratory cross-over study with a 2-week intervention diet based on either WG- or RG-based foods, separated by a washout of at least 5 weeks. Both diets were the same except for the use of WG (150 g/d) or RG foods. Subjects undertook a 4 h postprandial challenge on day 8 of each intervention diet. After 2 weeks, the WG diet tended to decrease plasma total and LDL-cholesterol (both P = 0·09), but did not change plasma HDL-cholesterol, fasting glucose, C-reactive protein or homocysteine compared with the RG diet. Plasma betaine and alkylresorcinol concentrations were elevated after 1 week of the WG diet (P = 0·01 and P < 0·0001, respectively). Clostridium leptum populations in faeces were increased after the WG diet, along with a trend for decreased faecal water pH (P = 0·096) and increased stool frequency (P < 0·0001) compared with the RG diet. A short controlled intervention trial with a variety of commercially available WG-based products tended to improve biomarkers of CVD compared with a RG diet. Changes in faecal microbiota related to increased fibre fermentation and increased plasma betaine concentrations point to both fibre and phytochemical components of WG being important in mediating any potential health effects.

The antiproliferative effect of dietary fiber phenolic compounds ferulic acid and p-coumaric acid on the cell cycle of Caco-2 cells

Epidemiological and animal studies have shown that dietary fiber is protective against the development of colon cancer. Dietary fiber is a rich source of the hydroxycinnamic acids ferulic acid (FA) and p-coumaric acid (p-CA), which both may contribute to the protective effect. We have investigated the effects of FA and p-CA treatment on global gene expression in Caco-2 colon cancer cells. The Caco-2 cells were treated with 150 μM FA or p-CA for 24 h, and gene expression was analyzed with cDNA microarray technique. A total of 517 genes were significantly affected by FA and 901 by p-CA. As we previously have found that FA or p-CA treatment delayed cell cycle progression, we focused on genes involved in proliferation and cell cycle regulation. The expressions of a number of genes involved in centrosome assembly, such as RABGAP1 and CEP2, were upregulated by FA treatment as well as the gene for the S phase checkpoint protein SMC1L1. p-CA treatment upregulated CDKN1A expression and downregulated CCNA2, CCNB1, MYC, and ODC1. Some proteins corresponding to the affected genes were also studied. Taken together, the changes found can partly explain the effects of FA or p-CA treatment on cell cycle progression, specifically in the S phase by FA and G(2)/M phase by p-CA treatment.

Constipation is relieved more by rye bread than wheat bread or laxatives without increased adverse gastrointestinal effects

Rye bread and lactobacilli modify the colonic environment and have the potential to relieve constipation and could be a safe and convenient alternative to laxatives. The effects of rye bread and cultured buttermilk with Lactobacillus rhamnosus GG (LGG) on bowel function and colon metabolism were investigated and compared with laxatives in 51 constipated adults. They were randomized to receive whole-grain rye bread (minimum 240 g/d), LGG (2 x 10(10) colony-forming units/d), whole-grain rye bread (minimum 240 g/d) + LGG (2 x 10(10) colony-forming units/d), white wheat bread (maximum 192 g/d), or laxatives (as usual for a participant) for 3 wk. Participants recorded their dietary habits, bowel function, and gastrointestinal symptoms. Fecal weight, pH, SCFA and bacterial enzyme activities, total intestinal transit time (TITT), and breath hydrogen were determined. Rye bread, compared with white wheat bread, shortened TITT by 23% (P = 0.040), increased weekly defecations by 1.4 (P = 0.014), softened feces [odds ratio (OR) 3.98; P = 0.037], eased defecation (OR 5.08; P = 0.018), increased fecal acetic acid and butyric acid contents by 24% (P = 0.044) and 63% (P <0.001), respectively, and reduced fecal beta-glucuronidase activity by 23% (P = 0.014). Compared with laxatives, rye bread reduced TITT by 41% (P = 0.006), fecal beta-glucuronidase activity by 38% (P = 0.033), and fecal pH by 0.31 units (P = 0.006). LGG did not relieve constipation or significantly affect colonic metabolism. Gastrointestinal adverse effects did not significantly differ among the study groups. In conclusion, rye bread relieves mild constipation and improves colonic metabolism compared with white wheat bread and commonly used laxatives without increasing gastrointestinal adverse effects.

Oral administration of sodium butyrate reduces chemically-induced preneoplastic lesions in experimental carcinogenesis

OBJECTIVE: The objective was to assess the effects of oral administration of sodium butyrate on colon carcinogenesis. METHODS: Carcinogenesis in adult male Wistar rats was induced with 1.2-dimethylhydrazine injections at a dose of 40mg/kg of body weight. A solution of sodium butyrate (3.4%) was given ad libitum for 4 weeks (butyrate group, n=16) instead of water (control group, n=9). Rats were killed 17 weeks after 1.2-dimethylhydrazine administration. Aberrant crypt foci and expression of the messenger ribonucleic acid (mRNA) of cyclins D1 and E were quantified in the colon. Alterations in the fatty acid profile of the colon, liver, intra-abdominal fat and feces were also analyzed. RESULTS: A significant decrease in aberrant crypt foci was found in the group taking butyrate. No differences were found between the groups in the mRNA expression of cyclins D1 and E. Nevertheless, butyrate intake decreased the content of stearic and oleic acids in the intra-abdominal fat and docosahexaenoic acid in the liver. Moreover, these rats presented higher percentages of linoleic acid in the intra-abdominal fat than control rats. CONCLUSION: The data indicate that butyrate use in rats reduced preneoplastic lesions and changes in the intra-abdominal fat and fatty acid profile of the liver, commonly found in colon carcinogenesis.

Grain foods and health: a primer for clinicians

Preventing many chronic diseases in North America requires substantial changes in dietary habits. Achieving a better balance of grain-based foods through the inclusion of whole grains is one scientifically supported dietary recommendation. Epidemiological and other types of research continue to document health benefits for diverse populations who have adequate intakes of both folic acid-fortified grain foods and whole grains. Folic acid fortification of grains is associated with reduced incidence of neural tube and other birth defects and may be related to decreased risk of other chronic disease. Whole grain intake is associated with reduced risk of chronic disease. Specifically, there is a decreased risk of obesity, coronary heart disease, hypertension, stroke, metabolic syndrome, type 2 diabetes, and some cancers observed among the highest whole grain eaters compared with those eating little or no whole grains. Nationally promulgated dietary recommendations such as those in the US Dietary Guidelines or by health promotion organizations such as the American Heart Association have incorporated the science on whole grains, recommending that consumers increase their whole grain intake. The US Dietary Guidelines state that consumers select half of the recommended bread and cereal servings as whole grain. Thus, the recommendations recognize the importance of adequate folic acid intake from refined, fortified grains to reduce the risk of birth defects and other disorders and to reflect the existing science on whole grains. The association between whole grains and decreased chronic disease is not surprising because whole grains are a source of vitamins, minerals, fatty acids, anti oxidants, and other phytochemicals and dietary fiber. Each of these components can act singly or in tandem to contribute to specific health-maintaining and disease-preventing mechanisms. Health professionals should be aware of these benefits and advocate these dietary strategies to help prevent chronic disease and to improve overall health.

KEYWORDS

nutrition; whole grain; folic acid; disease prevention; diet; mortality; diabetes; cereal; pseudocereal; phytochemicals; anti-oxidants.

The effect of drinking milk containing conjugated linoleic acid on fecal microbiological profile, enzymatic activity, and fecal characteristics in humans

Background

The primary objective was to determine whether consumption of conjugated linoleic acids (CLAs) affected the fecal microbiota composition, fecal enzyme activity or fecal composition.

Methods

Human subjects consumed (1 L/day) cows' milk (4% fat) containing (5 mg/g fat) cis-9, trans-11 CLA (CONT), (32 mg/g fat) cis-9, trans-11 CLA (NAT) and (32 mg/g fat) trans-10, cis-12 CLA and cis-9, trans-11 CLA (SYN) for 8 weeks, in addition to their normal diet. Milk feeding periods were separated by 4 week washout periods. Fecal samples were obtained at the beginning (day 0) and the end (day 56) of each milk feeding period. Fecal samples were analysed for microbiological profile, enzyme activity, pH and short chain fatty acid content.

Results

Samples taken at day 0 and day 56 indicated that the numbers of lactobacilli and bifidobacteria significantly decreased after consumption of all experimental milks; total aerobes, total anaerobes, enterobacteria, and enterococci + streptococci did not change. At day 56, the activities of β-glucosidase, nitroreductase, and urease enzymes had decreased compared to samples taken on day 0 for all treatments. β-glucuronidase activity did not change. Fecal pH and ammonia content did not change.

Conclusion

It was concluded that observed changes could have been attributed to increased milk intake; no differences could be attributed to consumption of the different CLAs.

Metabolism of trabectedin (ET-743, Yondelis™) in patients with advanced cancer

PURPOSE

Trabectedin (ET-743, Yondelis) is a novel anti-cancer drug currently undergoing phase II-III evaluation, that has shown remarkable activity in pre-treated patients with soft tissue sarcoma. Despite extensive pharmacokinetic studies, the human disposition and metabolism of trabectedin remain largely unknown. We aimed to determine the metabolic profile of trabectedin and to identify its metabolites in humans.

METHODS

We analysed urine and faeces (the major excretory route) from eight cancer patients after a 3 or 24 h intravenous administration of [14C]trabectedin. Using liquid chromatography with tandem quadrupole mass spectrometric detection (LC-MS/MS) and radiochromatography with off-line radioactivity detection by liquid scintillation counting (LC-LSC), we characterised the metabolic profile in 0-24 h urine and 0-120 h faeces.

RESULTS

By radiochromatography, a large number of trabectedin metabolites were detected. Incubation with beta-glucuronidase indicated the presence of a glucuronide metabolite in urine. Trabectedin, ET-745, ET-759A, ETM-259, ETM-217 (all available as reference compounds) and a proposed new metabolite coined ET-731 were detected using LC-MS/MS. The inter-individual differences in radiochromatographic profiles were small and did not correlate with polymorphisms in drug-metabolising enzymes (CYP2C9, 2C19, 2D6, 2E1, 3A4, GST-M1, P1, T1 and UGT1A1 2B15) as determined by genotyping.

CONCLUSIONS

Trabectedin is metabolically converted to a large number of compounds that are excreted in both urine and faeces. In urine and faeces we have confirmed the presence of trabectedin, ET-745, ET-759A, ETM-259, ETM-217 and ETM-204. In addition we have identified a putative new metabolite designated ET-731. Future studies should be aimed at further identification of possible metabolites and assessment of their activity.

A combination of fibre-rich rye bread and yoghurt containing Lactobacillus GG improves bowel function in women with self-reported constipation

OBJECTIVE

The aim of the study was to investigate the effects of fibre-rich rye bread and yoghurt containing Lactobacillus GG (LGG) on intestinal transit time and bowel function, and to test whether they have an interaction in cases of self-reported constipation.

DESIGN

The study was carried out as a two-by-two factorial design.

SETTING

Free-living subjects.

SUBJECTS

A total of 59 healthy women with self-reported constipation, recruited by advertisement.

INTERVENTIONS

After a baseline period, the subjects were randomized into four diet groups: (1) rye bread+LGG yoghurt, (2) rye bread, (3) LGG yoghurt, and (4) control. The 3-week dietary intervention was followed by a 3-week follow-up period. During each period, total intestinal transit time was measured and the subjects recorded faecal frequency and consistency, difficulty in defecation and gastrointestinal symptoms.

RESULTS

The rye bread shortened total intestinal transit time (mean difference, -0.7; CI(95), -1.1 to -0.2; P=0.007), increased faecal frequency (0.3; CI(95), 0.1 to 0.5; P=0.001), softened faeces (-0.3; CI(95), -0.4 to -0.2; P<0.001) and made defecation easier (-0.4; CI(95), -0.5 to -0.2; P<0.001), but also increased gastrointestinal symptoms (1.6; CI(95), 0.7 to 2.4; P<0.001) compared to the low-fibre toast consumed in the LGG and control groups. There were fewer symptoms in the rye bread+LGG group compared to the rye bread group (-1.3; CI(95), -2.4 to -0.2; P=0.027).

CONCLUSIONS

Fibre-rich rye bread can be recommended in the treatment of constipation, and the simultaneous consumption of LGG yoghurt relieves the adverse gastrointestinal effects associated with increased intake of fibre.

SPONSORSHIP

Valio Ltd, R&D, and Fazer Bakeries Ltd.

Lupin kernel fibre foods improve bowel function and beneficially modify some putative faecal risk factors for colon cancer in men

Consumption of some dietary fibres may benefit bowel health; however, the effect of Australian sweet lupin (Lupinus angustifolius) kernel fibre (LKFibre) is unknown. The present study examined the effect of a high-fibre diet containing LKFibre on bowel function and faecal putative risk factors for colon cancer compared to a control diet without LKFibre. Thirty-eight free-living, healthy men consumed an LKFibre and a control diet for 1 month each in a single-blind, randomized, crossover study. Depending on subject energy intake, the LKFibre diet was designed to provide 17-30 g/d fibre (in experimental foods) above that of the control diet. Bowel function self-perception, frequency of defecation, transit time, faecal output, pH and moisture, faecal levels of SCFA and ammonia, and faecal bacterial beta-glucuronidase activity were assessed. In comparison to the control diet, the LKFibre diet increased frequency of defecation by 0.13 events/d (P=0.047), increased faecal output by 21 % (P=0.020) and increased faecal moisture content by 1.6 % units (P=0.027), whilst decreasing transit time by 17 % (P=0.012) and decreasing faecal pH by 0.26 units (P<0.001). Faecal butyrate concentration was increased by 16 % (P=0.006), butyrate output was increased by 40 % (P=0.002) and beta-glucuronidase activity was lowered by 1.4 micromol/h per g wet faeces compared to the control diet (P<0.001). Addition of LKFibre to the diet incorporated into food products improved some markers of healthy bowel function and colon cancer risk in men.

Effect of isomalt consumption on faecal microflora and colonic metabolism in healthy volunteers

Due to its low digestibility in the small intestine, a major fraction of the polyol isomalt reaches the colon. However, little is known about effects on the intestinal microflora. During two 4-week periods in a double-blind, placebo-controlled, cross-over design, nineteen healthy volunteers consumed a controlled basal diet enriched with either 30 g isomalt or 30 g sucrose daily. Stools were collected at the end of each test phase and various microbiological and luminal markers were analysed. Fermentation characteristics of isomalt were also investigated in vitro. Microbiological analyses of faecal samples indicated a shift of the gut flora towards an increase of bifidobacteria following consumption of the isomalt diet compared with the sucrose diet (P<0.05). During the isomalt phase, the activity of bacterial beta-glucosidase decreased (P<0.05) whereas beta-glucuronidase, sulfatase, nitroreductase and urease remained unchanged. Faecal polyamines were not different between test periods with the exception of cadaverine, which showed a trend towards a lower concentration following isomalt (P=0.055). Faecal SCFA, lactate, bile acids, neutral sterols, N, NH3, phenol and p-cresol were not affected by isomalt consumption. In vitro, isomalt was metabolized in several bifidobacteria strains and yielded high butyrate concentrations. Isomalt, which is used widely as a low-glycaemic and low-energy sweetener, has to be considered a prebiotic carbohydrate that might contribute to a healthy luminal environment of the colonic mucosa.

Monochloramine inhibits ultraviolet B-induced p53 activation and DNA repair response in human fibroblasts

Monochloramine (NH2Cl) is one of the inflammation-derived oxidants, and has various effects on cell cycle, apoptosis and signal transduction. We studied the effects of NH2Cl on DNA repair response induced by ultraviolet B (UVB) irradiation in normal human diploid fibroblasts, TIG-1. TIG-1 irradiated with 20 mJ/cm2 UVB showed marked increase in thymine dimer, which decreased by about 50% after 24 h. This decrease in thymine dimer was significantly attenuated (P < 0.05) by the pretreatment of NH2Cl (200 microM), which indicated DNA repair inhibition. UVB induced p53 phosphorylation at Ser15, Ser20 and Ser37, and p53 accumulation, and NH2Cl also inhibited these changes. Consequently, UVB-induced increase in the downstream effectors of p53, namely p21Cip1 and Gadd45a, were almost completely inhibited by NH2Cl. Immunoprecipitation study indicated that the association of p53 and MDM2, an E3 ubiquitin ligase for p53, did not change substantially by NH2Cl and/or UVB. The phosphorylation of p53 (Ser15 and Ser37) by UVB is catalyzed by ATR (ataxia telangiectasia mutated and Rad3 related kinase), which works as DNA damage sensor, and ATR also phosphorylates checkpoint kinase 1(Chk1) at Ser345. NH2Cl also inhibited the phosphorylation of Chk1 (Ser345). As UVB-induced DNA damage is repaired by nucleotide excision repair (NER) in human cells, these findings indicated that NH2Cl inhibited NER through the inhibition of p53 phosphorylation and accumulation, and NH2Cl probably impaired DNA damage recognition and/or ATR activation. NH2Cl may facilitate carcinogenesis through the inhibition of NER that repairs DNA damages from various carcinogens.

Oxidative modification of IκB by monochloramine inhibits tumor necrosis factor α-induced NF-κB activation

We have previously reported that monochloramine (NH(2)Cl), a neutrophil-derived oxidant, inhibited tumor necrosis factor alpha (TNFalpha)-induced expression of cell adhesion molecules and nuclear factor-kappaB (NF-kappaB) activation (Free Radical Research 36 (2002) 845-852). Here, we studied the mechanism how NH(2)Cl inhibited TNFalpha-induced NF-kappaB activation, and compared the effects with taurine chloramine (Tau-NHCl). Pretreatment of Jurkat cells with NH(2)Cl at 70 microM resulted in suppression of TNFalpha-induced IkappaB phosphorylation and degradation, and inhibited NF-kappaB activation. In addition, a slow-moving IkappaB band appeared on SDS-PAGE. By contrast, Tau-NHCl for up to 200 microM had no effects. Interestingly, NH(2)Cl did not inhibit IkappaB kinase activation by TNFalpha. Protein phosphatase activity did not show apparent change. When recombinant IkappaB was oxidized by NH(2)Cl in vitro and phosphorylated by TNFalpha-stimulated Jurkat cell lysate, its phosphorylation occurred less effectively than non-oxidized IkappaB. In addition, when NF-kappaB-IkappaB complex was immunoprecipitated from NH(2)Cl-treated cells and phosphorylated in vitro by recombinant active IkappaB kinase, native IkappaB but not oxidized IkappaB was phosphorylated. Amino acid analysis of the in vitro oxidized IkappaB showed methionine oxidation to methionine sulfoxide. Although Tau-NHCl alone had little effects on TNFalpha-induced NF-kappaB activation, simultaneous presence of Tau-NHCl and ammonium ion significantly inhibited the NF-kappaB activation, probably through the conversion of Tau-NHCl to NH(2)Cl. These results indicated that NH(2)Cl inhibited TNFalpha-induced NF-kappaB activation through the oxidation of IkappaB, and that NH(2)Cl is physiologically more relevant than Tau-NHCl in modifying NF-kappaB-mediated cellular responses.

Dietary lignans: potential role in cancer prevention

Recent in vitro, animal, and epidemiological studies suggest that dietary lignans may be chemopreventive, potentially through anti-estrogenic, anti-angiogenic, pro- apoptotic, and anti-oxidant mechanisms. In this article, we review lignan food sources and metabolism, proposed anti-carcinogenic mechanisms, and the evidence for a role of lignans in breast, colon, and prostate cancer prevention from animal and epidemiologic literature. Although a number of in vitro and animal studies support a role for lignan-rich foods and purified lignans in the modulation of cancer events of the breast, prostate, and colon, epidemiological studies, sparse and often retrospective in nature, offer inconsistent findings. The most support for a role of lignans in cancer is observed for premenopausal breast cancer. Additional epidemiological studies that use a prospective design and well-developed food databases and questionnaires are needed to adequately evaluate the role of lignans in cancer prevention.