2,726 research outputs found
Management of oedematous malnutrition in infants and children aged >6 months: a systematic review of the evidence
Desarrollo y evaluación de un cuestionario semi-cuantitativo de frecuencias alimenticias para adolescentes bolivianos
Introduction: Since previous studies suggest that the dietary patterns and lifestyle in adolescence have an impact in health later in life, it is pertinent to monitor and document their dietary patterns.
Objective: To develop and test the reliability and validity of a semi-quantitative food frequency questionnaire for Bolivian adolescents.
Setting: La Paz, September - October 2004.
Methodology: A convenience sample of 82 students from a secondary participated in the study. A semi quantitative food frequency questionnaire was applied twice with one month interval (Q1 and Q2). A 3 days dietary record (3R) was obtained from 32 of the Students as standard.
Results: Most of the questions (87%) reporting intake of each individual food item agreed moderately to substantially while only 2 individual food items fell into the category of slight agreement and 11 into the category of fair agreement using the kappa statistic. Quantities obtained from both applications of the questionnaire yielded similar results (P > 0.05). Nutrient estimates obtained from the Q1 and Q2 and the 3R were not statistically different (P > 0.05).
Conclusion: The semi - quantitative food frequency questionnaire is apparently reliable and valid for the measurement of absolute food intake in Bolivian adolescents. Care will be taken in the future to prevent overestimation of intake measured by this particular questionnaire
FabR regulates Salmonella biofilm formation via its direct target FabB
Background: Biofilm formation is an important survival strategy of Salmonella in all environments. By mutant screening, we showed a knock-out mutant of fabR, encoding a repressor of unsaturated fatty acid biosynthesis (UFA), to have impaired biofilm formation. In order to unravel how this regulator impinges on Salmonella biofilm formation, we aimed at elucidating the S. Typhimurium FabR regulon. Hereto, we applied a combinatorial high-throughput approach, combining ChIP-chip with transcriptomics.
Results: All the previously identified E. coli FabR transcriptional target genes (fabA, fabB and yqfA) were shown to be direct S. Typhimurium FabR targets as well. As we found a fabB overexpressing strain to partly mimic the biofilm defect of the fabR mutant, the effect of FabR on biofilms can be attributed at least partly to FabB, which plays a key role in UFA biosynthesis. Additionally, ChIP-chip identified a number of novel direct FabR targets (the intergenic regions between hpaR/hpaG and ddg/ydfZ) and yet putative direct targets (i.a. genes involved in tRNA metabolism, ribosome synthesis and translation). Next to UFA biosynthesis, a number of these direct targets and other indirect targets identified by transcriptomics (e.g. ribosomal genes, ompA, ompC, ompX, osmB, osmC, sseI), could possibly contribute to the effect of FabR on biofilm formation.
Conclusion: Overall, our results point at the importance of FabR and UFA biosynthesis in Salmonella biofilm formation and their role as potential targets for biofilm inhibitory strategies
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Prebiotic effects: metabolic and health benefits
The different compartments of the gastrointestinal tract are inhabited by populations of micro-organisms. By far the most important predominant populations are in the colon where a true symbiosis with the host exists that is a key for well-being and health. For such a microbiota, 'normobiosis' characterises a composition of the gut 'ecosystem' in which micro-organisms with potential health benefits predominate in number over potentially harmful ones, in contrast to 'dysbiosis', in which one or a few potentially harmful micro-organisms are dominant, thus creating a disease-prone situation. The present document has been written by a group of both academic and industry experts (in the ILSI Europe Prebiotic Expert Group and Prebiotic Task Force, respectively). It does not aim to propose a new definition of a prebiotic nor to identify which food products are classified as prebiotic but rather to validate and expand the original idea of the prebiotic concept (that can be translated in 'prebiotic effects'), defined as: 'The selective stimulation of growth and/or activity(ies) of one or a limited number of microbial genus(era)/species in the gut microbiota that confer(s) health benefits to the host.' Thanks to the methodological and fundamental research of microbiologists, immense progress has very recently been made in our understanding of the gut microbiota. A large number of human intervention studies have been performed that have demonstrated that dietary consumption of certain food products can result in statistically significant changes in the composition of the gut microbiota in line with the prebiotic concept. Thus the prebiotic effect is now a well-established scientific fact. The more data are accumulating, the more it will be recognised that such changes in the microbiota's composition, especially increase in bifidobacteria, can be regarded as a marker of intestinal health. The review is divided in chapters that cover the major areas of nutrition research where a prebiotic effect has tentatively been investigated for potential health benefits. The prebiotic effect has been shown to associate with modulation of biomarkers and activity(ies) of the immune system. Confirming the studies in adults, it has been demonstrated that, in infant nutrition, the prebiotic effect includes a significant change of gut microbiota composition, especially an increase of faecal concentrations of bifidobacteria. This concomitantly improves stool quality (pH, SCFA, frequency and consistency), reduces the risk of gastroenteritis and infections, improves general well-being and reduces the incidence of allergic symptoms such as atopic eczema. Changes in the gut microbiota composition are classically considered as one of the many factors involved in the pathogenesis of either inflammatory bowel disease or irritable bowel syndrome. The use of particular food products with a prebiotic effect has thus been tested in clinical trials with the objective to improve the clinical activity and well-being of patients with such disorders. Promising beneficial effects have been demonstrated in some preliminary studies, including changes in gut microbiota composition (especially increase in bifidobacteria concentration). Often associated with toxic load and/or miscellaneous risk factors, colon cancer is another pathology for which a possible role of gut microbiota composition has been hypothesised. Numerous experimental studies have reported reduction in incidence of tumours and cancers after feeding specific food products with a prebiotic effect. Some of these studies (including one human trial) have also reported that, in such conditions, gut microbiota composition was modified (especially due to increased concentration of bifidobacteria). Dietary intake of particular food products with a prebiotic effect has been shown, especially in adolescents, but also tentatively in postmenopausal women, to increase Ca absorption as well as bone Ca accretion and bone mineral density. Recent data, both from experimental models and from human studies, support the beneficial effects of particular food products with prebiotic properties on energy homaeostasis, satiety regulation and body weight gain. Together, with data in obese animals and patients, these studies support the hypothesis that gut microbiota composition (especially the number of bifidobacteria) may contribute to modulate metabolic processes associated with syndrome X, especially obesity and diabetes type 2. It is plausible, even though not exclusive, that these effects are linked to the microbiota-induced changes and it is feasible to conclude that their mechanisms fit into the prebiotic effect. However, the role of such changes in these health benefits remains to be definitively proven. As a result of the research activity that followed the publication of the prebiotic concept 15 years ago, it has become clear that products that cause a selective modification in the gut microbiota's composition and/or activity(ies) and thus strengthens normobiosis could either induce beneficial physiological effects in the colon and also in extra-intestinal compartments or contribute towards reducing the risk of dysbiosis and associated intestinal and systemic pathologies
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Consumption of Bifidobacterium lactose Bi-07 by healthy elderly adults enhances phagocytic activity of monocytes and granulocytes
Elderly adults have alterations in their gut microbiota and immune functions that are associated with higher susceptibility to infections and metabolic disorders. Probiotics and prebiotics, and their synbiotic combinations are food supplements that have been shown to improve both gut and immune function. The objective of this randomised, double-blind, placebo-controlled, cross-over human clinical trial was to study immune function and the gut microbiota in healthy elderly adults. Volunteers (n 37) consumed prebiotic galacto-oligosaccharides (GOS; 8 g/d), probiotic Bifidobacterium lactis Bi-07 (Bi-07; 109 colony- forming units/d), their combination (Bi-07 + GOS) and maltodextrin control (8 g/d) in four 3-week periods separated by 4-week wash-out periods. Immune function was analysed by determining the phagocytic and oxidative burst activity of monocytes and granulocytes, whole-blood response to lipo- polysaccharide, plasma chemokine concentrations and salivary IgA levels. Gut microbiota composition and faecal SCFA content were determined using 16S ribosomal RNA fluorescence in situ hybridisation and HPLC, respectively. Primary statistical analyses indicated the presence of carry-over effects and thus measurements from only the first supplementation period were considered valid. Subsequent statistical analysis showed that consumption of Bi-07 improved the phagocytic activity of monocytes (P < 0·001) and granulocytes (P = 0·02). Other parameters were unchanged. We have for the first time shown that the probiotic Bi-07 may provide health benefits to elderly individuals by improving the phagocytic activity of monocytes and granulocytes. The present results also suggest that in the elderly, the effects of some probiotics and prebiotics may last longer than in adults
Fatores afetando o consumo e utilização de forrageiras de baixa qualidade por ruminantes - revisão.
A quantidade máxima de alimento capaz de ser consumida por um ruminante e de grande importância para o produtor. De um modo geral, quanto maior for o consumo, menor será a quantidade de alimento necessário por unidade de produção. Este fato e que caracteriza a eficiência produtiva de um animal. A conseqüência econômica seria que maiores lucros estariam dependentes da capacidade dos ruminantes em digerir alimentos fibrosos mais baratos e disponíveis em maiores quantidades. O Maximo consumo de uma forragem pelo ruminante depende, primariamente, das taxas de escoamento do rúmen da celulose e hemicelulose. Estas taxas, por sua vez, depende de vários fatores que interferem na atividade da flora microbiana do rúmen, quais sejam: evolução do processo de lignificação com o estágio de maturação das forrageiras, parcial ausência de nutrientes para a microflora como nitrogênio ou minerais e a presença em excesso de agentes bacteriostáticos. Dada a sua importância econômica e cientifica, este assunto vem sendo estudado extensivamente por nutricionistas e fisiologistas em varias partes do mundo, gerando uma enorme gama de conceitos relacionados ao binômio animal-planta, parte dos quais foram reunidos no presente trabalho de revisão.bitstream/item/131377/1/fatores-afetando-o-consumo.pd
Nutritional profile of foods offered and consumed in a Belgian university canteen
Objective: To evaluate the nutritional profile of a lunch offered and consumed in a university canteen in Belgium.
Design: The qualitative and quantitative content of 4365 meals theoretically available and 330 meals consumed was recorded during five weekdays spread over three weeks. Meal combinations were evaluated using a scoring system based on recommendations for Na content, energy from fat, and fruit and vegetable portions.
Setting: University canteen in Belgium.
Results: Only a 5 % of the meal combinations available and consumed complied with the three basic dietary recommendations for a hot lunch. The nutritional profile of the meals consumed was in line with that of the meals available.
Conclusions: Our results show how the nutritional profile of what is eaten is largely determined by what is offered. To ensure overall compliance with dietary recommendations, considerable changes on the supply side, i.e. an increase in fruit and vegetable portions and a reduction in salt and fat of the lunch, are needed first in our setting. Our assessment provides baseline data to pilot a nutrient profiling intervention and shows how a nutrient profiling system can be used for meal evaluation purposes
Xylo-oligosaccharides and inulin affect genotoxicity and bacterial populations differently in a human colonic simulator challenged with soy protein.
High dietary intakes of some protein sources, including soy protein, can increase colonic DNA damage in animals, whereas some carbohydrates attenuate this. We investigated whether inulin and xylo-oligosaccharides (XOS) could be protective against DNA strand breaks by adding them to a human colonic simulator consisting of a proximal vessel (PV) (pH 5.5) and a distal vessel (DV) (pH 6.8) inoculated with human faeces and media containing soy protein. Genotoxicity of the liquid phase and microbial population changes in the vessels were measured. Soy protein (3%) was fermented with 1% low amylose cornstarch for 10 day followed by soy protein with 1% XOS or 1% inulin for 10 day. Inulin did not alter genotoxicity but XOS significantly reduced PV genotoxicity and increased DV genotoxicity. Inulin and XOS significantly increased butyrate concentration in the DV but not PV. Numbers of the key butyrate-producing bacterium Faecalibacterium prausnitzii were significantly increased in the PV and DV by inulin but significantly decreased by XOS in both vessels. Other bacteria examined were also significantly impacted by the carbohydrate treatments or by the vessel (i.e., pH). There was a significant overall inverse correlation between levels of damage induced by the ferments and levels of sulphate-reducing bacteria, Bacteroides fragilis, and acetate. In conclusion, dietary XOS can potentially modulate the genotoxicity of the colonic environment and specific bacterial groups and short chain fatty acids may mediate this
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