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Effects of Trifluralin on Corn (Zea mays) Growth and Nutrient Content
- Robert G. Hartzler, Richard S. Fawcett, Henry G. Taber
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- Journal:
- Weed Science / Volume 38 / Issue 6 / November 1990
- Published online by Cambridge University Press:
- 12 June 2017, pp. 468-470
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Glasshouse experiments were conducted to determine the effects of trifluralin on root growth and mineral relations of corn seedlings. Root weight to shoot weight ratios of corn seedlings were positively correlated to concentrations of trifluralin in soil. Root length to shoot weight ratios, however, were inversely related to trifluralin concentrations. Phosphorous and potassium concentrations in shoot tissue were reduced 60 and 35%, respectively, by 0.25 mg trifluralin kg−1 soil. Growth inhibition due to trifluralin was partially overcome by supplementing soil with nutrients.
Prebiotic effects: metabolic and health benefits
- Marcel Roberfroid, Glenn R. Gibson, Lesley Hoyles, Anne L. McCartney, Robert Rastall, Ian Rowland, Danielle Wolvers, Bernhard Watzl, Hania Szajewska, Bernd Stahl, Francisco Guarner, Frederique Respondek, Kevin Whelan, Veronique Coxam, Marie-Jeanne Davicco, Laurent Léotoing, Yohann Wittrant, Nathalie M. Delzenne, Patrice D. Cani, Audrey M. Neyrinck, Agnes Meheust
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- Journal:
- British Journal of Nutrition / Volume 104 / Issue S2 / August 2010
- Published online by Cambridge University Press:
- 01 August 2010, pp. S1-S63
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- August 2010
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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.
Low levels of faecal lactobacilli in women with iron-deficiency anaemia in south India
- Ramadass Balamurugan, R. Regina Mary, Sucharita Chittaranjan, Hepsiba Jancy, R. Shobana Devi, Balakrishnan S. Ramakrishna
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- Journal:
- British Journal of Nutrition / Volume 104 / Issue 7 / 14 October 2010
- Published online by Cambridge University Press:
- 07 May 2010, pp. 931-934
- Print publication:
- 14 October 2010
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Fe deficiency in women contributes significantly to maternal and child morbidity in India. The intestinal bacterial flora may facilitate absorption of Fe from the caecum and proximal colon. The present study investigated the possibility that intestinal microbiota of anaemic young women may differ from that of women with normal Hb levels. The microbiota was quantified by real-time PCR in faeces of eight anaemic (Hb ≤ 100 g/l) and twenty-six normohaemic (Hb ≥ 120 g/l) women aged 18–25 years. Sequences of 16S ribosomal DNA (rDNA) specific to Bifidobacterium genus, Lactobacillus acidophilus group, Bacteroides–Prevotella–Porphyromonas group, Clostridium leptum group and Eubacterium rectale were amplified and expressed (as relative difference) relative to the universally conserved bacterial 16S rDNA sequences. Dietary intakes of energy, carbohydrate, fibre and Fe were ascertained by maintenance of a diet diary for a week. Faecal lactobacilli were significantly lower in anaemic women (median 6·6 × 10− 8, relative difference compared with total bacteria) than in the reference group (2·9 × 10− 6; P = 0·001, unpaired t test with logarithmic transformation). There was no difference between the two groups with respect to any of the other bacteria that were examined. Intakes of energy, carbohydrate, fibre, Fe and milk were similar in both the groups. Fe deficiency in young women in south India was associated with low levels of lactobacilli in the faeces. The relationship between lactobacilli and Fe deficiency needs to be explored further.
Effects of oligofructose-enriched inulin on intestinal absorption of calcium and magnesium and bone turnover markers in postmenopausal women
- Leah Holloway, Sharon Moynihan, Steven A. Abrams, Kyla Kent, Andrew R. Hsu, Anne L. Friedlander
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- Journal:
- British Journal of Nutrition / Volume 97 / Issue 2 / February 2007
- Published online by Cambridge University Press:
- 01 February 2007, pp. 365-372
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- February 2007
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Deficiency of oestrogen at menopause decreases intestinal Ca absorption, contributing to a negative Ca balance and bone loss. Mg deficiency has also been associated with bone loss. The purpose of the present investigation was to test the hypothesis that treatment with a spray-dried mixture of chicory oligofructose and long-chain inulin (Synergy1; SYN1) would increase the absorption of both Ca and Mg and alter markers of bone turnover. Fifteen postmenopausal women (72·2 (sd 6·4) years) were treated with SYN1 or placebo for 6 weeks using a double-blind, placebo-controlled, cross-over design. Fractional Ca and Mg absorption were measured using dual-tracer stable isotopes before and after treatment. Bone turnover markers were measured at baseline, 3 and 6 weeks. Fractional absorption of Ca and Mg increased following SYN1 compared with placebo (P < 0·05). Bone resorption (by urinary deoxypyridinoline cross-links) was greater than baseline at 6 weeks of active treatment (P < 0·05). Bone formation (by serum osteocalcin) showed an upward trend at 3 weeks and an increase following 6 weeks of SYN1 (P < 0·05). Closer examination revealed a variation in response, with two-thirds of the subjects showing increased absorption with SYN1. Post hoc analyses demonstrated that positive responders had significantly lower lumbar spine bone mineral density than non-responders (dual X-ray absorptiometry 0·887 ± 0·102 v. 1·104 ± 0·121 g/cm2; P < 0·01), and changes in bone turnover markers occurred only in responders. These results suggest that 6 weeks of SYN1 can improve mineral absorption and impact markers of bone turnover in postmenopausal women. Further research is needed to determine why a greater response was found in women with lower initial spine bone mineral density.
The effects of increasing the sodium content of grass or concentrates on the nutrition of sheep
- C. J. C. Phillips, M. O. Mohamed, H. Omed
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- Journal:
- Animal Science / Volume 77 / Issue 3 / December 2003
- Published online by Cambridge University Press:
- 18 August 2016, pp. 491-498
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- December 2003
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Supplementary salt is often added to the diet of sheep by including it in concentrate food, but an alternative is to soak their forage in a weak salt solution, which could prevent the sudden influx of large doses of sodium(Na) to the rumen. An experiment was conducted to compare low and moderate levels of salt in forage with moderate and high levels added to the concentrate. Twenty sheep were housed in individual chambers equipped for faeces and urine collection and offered fresh grass and concentrate, with the salt being added to the grass by soaking in salt water and to the concentrate by direct mixing. The grass for sheep offered the supplementary Na in concentrates and for a control treatment was soaked in water without salt. Grass was offered in two daily meals and was available ad libitum, and concentrates were offered at a restricted level just before the first feeding of grass. Adding salt at the low and moderate levels to the water in which the grass was soaked increased the Na intake from 1·1 g/day (the control treatment) to 2·1 and 3·8 g/day, respectively, and reduced the Mg and Ca contents in the grass, compared with grass soaked in unsalted water. Adding salt to the concentrate at moderate and high levels increased Na intake to 3·7 and 5·9 g/day, respectively. Grass dry matter (DM) intakes were increased by adding Na to the concentrates, but not to the grass, and DM digestibility was increased in all salt supplement treatments except the high level added to the concentrate. The apparent absorption of Na was increased in proportion to the amount of Na added to the diet and that of K was increased at the moderate and high levels. The apparent absorption and retention of Mg and Ca were decreased at the low level of Na supplementation in herbage. It is concluded that the potential benefits of adding salt to the diet, namely increased food intake and digestibility and increased mineral absorption, are dependent on the level of addition and the method of adding it.
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