1. Three groups of sheep receiving 400, 800 and 1200 g lucerne chaff/d in equal hourly meals were killed. The large intestines were removed and divided into segments 15 cm long to provide information on the amounts and dry-matter contents of digesta and on the rates of passage of digesta and absorption of water along the large intestine.

2. With increasing intakes of food, increases were observed along the entire large intestine in the amounts of wet digesta present, in the transit rates of digesta and in the rates of absorption of water. The mean retention time of digesta in the large intestine decreased with increasing food intake, being 1737, 1056 and 692 min respectively.

3. Four patterns of sodium and potassium concentrations in digesta water along the large intestine were found.

The goal of eating five servings of fruits and vegetables a day has not yet been achieved. The intake of polyphenols such as anthocyanins (ACN) could be improved by consuming smoothies and juices that are increasingly popular, especially in children; however, bioavailability data concerning food matrix effects are scarce. Thus, we conducted a randomised, cross-over, bioavailability study (n 10) to determine the bioavailability of ACN and their metabolites from an ACN-rich grape/blueberry juice (841 mg ACN/litre) and smoothie (983 mg ACN/litre) in vivo, and the uptake of a corresponding grape/blueberry extract in vitro. After the intake of beverage (0·33 litres), plasma and fractionated urine samples were collected and analysed by ultra-performance liquid chromatography coupled to MS. The most abundant ACN found in plasma and urine were malvidin and peonidin as native ACN and as glucuronidated metabolites as well as 3,4-dihydroxybenzoic acid (3,4-DHB); minor ACN (delphinidin, cyanidin and petunidin) were only detected as native glycosides. Plasma pharmacokinetics and recoveries of urinary metabolites of ACN were not different for juice or smoothie intake; however, the phenolic acid 3,4-DHB was significantly better bioavailable from juice in comparison to smoothie. In vitro data with absorptive intestinal cells indicated that despite their weak chemical stability, ACN and 3,4-DHB could be detected at the basal side in their native forms. Whether smoothies as well as juices should be recommended to increase the intake of potentially health-promoting ACN and other polyphenols requires the consideration of other ingredients such as their relatively high sugar content.

Twelve male subjects took part in a study to investigate the effects of overfeeding a high-fat diet (19·17 MJ/d; 58% energy from fat) for 2 weeks on plasma cholecystokinin (CCK) levels, food intake, and subjective feelings of hunger and fullness. Before and after the diet, subjects completed a 2-week weighed dietary inventory, formal measurements of food intake from a pre-selected appetizing evening meal were carried out, and blood samples were taken after a standard breakfast for measurement of CCK. Hunger and fullness were rated on visual analogue scales before and after each of these meals and at evening meals during the diet period. Following the high-fat diet there was a small non-significant increase in food intake from the pre-selected meal (6919 (SE 615) kJ ν 6405 (SE 540) kJ; P = 0·1) and a significant increase in the average daily food consumption measured from the diaries (10·25 (SE 0·49) MJ/d ν. 9·59 (SE 0·62) MJ/d; P = 0·05). Corresponding trends of increasing feelings of hunger and declining fullness also occurred over the study period. Plasma CCK responses to the standard breakfast were raised following the diet (1285 (SE 153) ν. 897 (SE 78) pM min; 3h integrated CCK production post ν. pre diet; P < ·01) with the major differences observed at 90 and 120 min following the meal. These results suggest that the increase in food intake may be related to a down-regulation in putative CCK receptors responsible for food intake. Elevated CCK levels might suggest a corresponding down-regulation in CCK receptors responsible for feedback inhibition of CCK release.

1. Four human subjects on strictly controlled diets were given a fibre supplement, 25 g Ispaghula husk (Isogel)/d, for 3 weeks.

2. Replicate diets and faeces were collected during two 5 d balance periods. The first period served as control for the second which occurred after the supplement had been fed for 2 weeks.

3. Diets and faeces were analysed for total solids, gross energy, total nitrogen, fat, available and unavailable carbohydrates.

4. Three of the four subjects showed a considerable increase in faecal bulk; total faecal weight was more than doubled in two subjects. In two subjects the increase was brought about mainly by extra fibre in the faeces accompanied by a higher proporation of faecal water whereas in one subject it was also an increased excretion of nutrients. One subject showed very little change in faecal bulk.

5. High values for the apparent digestibility of fibre were found during the control period; from 0.70 to 0.80. There was more variation during the experimental period when apparent digestibility of total fibre ranged from 0.47 to 0.82. Values arrived at for the minimum apparent digestibility of the fibre supplement were generally high; one subject appeared to digest Isogel completely. Isogel was degraded preferentially to the food-derived fibre; in particular, cellulose in the faeces was increased during the experimental period.

6. Only one subject showed distinct decreases in the apparent digestibility of energy, N and fat in the diet. The results do not therefore agree with the generally held view that increased fibre in the diet decreases the apparent digestibility of the other nutrients.

Phenolic acids are secondary plant metabolites that may have protective effects against oxidative stress, inflammation and cancer in experimental studies. To date, limited data exist on the quantitative intake of phenolic acids. We estimated the intake of phenolic acids and their food sources and associated lifestyle factors in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Phenolic acid intakes were estimated for 36 037 subjects aged 35–74 years and recruited between 1992 and 2000 in ten European countries using a standardised 24 h recall software (EPIC-Soft), and their food sources were identified. Dietary data were linked to the Phenol-Explorer database, which contains data on forty-five aglycones of phenolic acids in 452 foods. The total phenolic acid intake was highest in Aarhus, Denmark (1265·5 and 980·7 mg/d in men and women, respectively), while the intake was lowest in Greece (213·2 and 158·6 mg/d in men and women, respectively). The hydroxycinnamic acid subclass was the main contributor to the total phenolic acid intake, accounting for 84·6–95·3 % of intake depending on the region. Hydroxybenzoic acids accounted for 4·6–14·4 %, hydroxyphenylacetic acids 0·1–0·8 % and hydroxyphenylpropanoic acids ≤ 0·1 % for all regions. An increasing south–north gradient of consumption was also found. Coffee was the main food source of phenolic acids and accounted for 55·3–80·7 % of the total phenolic acid intake, followed by fruits, vegetables and nuts. A high heterogeneity in phenolic acid intake was observed across the European countries in the EPIC cohort, which will allow further exploration of the associations with the risk of diseases.

Dietary fibre sources are fermented by the gut flora to yield short-chain fatty acids (SCFA) together with degraded phytochemicals and plant nutrients. Butyrate, a major SCFA, is potentially chemoprotective by suppressing the growth of tumour cells and enhancing their differentiation. Conversely, it could lead to a positive selection pressure for transformed cells by inducing glutathione S-transferases (GST) and enhancing chemoresistance. Virtually nothing is known about how butyrate's activities are affected by other fermentation products. To investigate such interactions, a variety of dietary fibre sources was fermented with human faecal slurries in vitro, analysed for SCFA, and corresponding SCFA mixtures were prepared. HT29 colon tumour cells were treated for 72 h with individual SCFA or complex samples. The growth of cells, GST activity, and chemoresistance towards 4-hydroxynonenal were determined. Fermentation products inhibited cell growth more than the corresponding SCFA mixtures, and the SCFA mixtures were more active than butyrate, probably due to phytoprotectants and to propionate, respectively, which also inhibit cell growth. Only butyrate induced GST, whereas chemoresistance was caused by selected SCFA mixtures, but not by all corresponding fermentation samples. In summary, fermentation supernatant fractions contain compounds that: (1) enhance the anti-proliferative properties of butyrate (propionate, phytochemical fraction); (2) do not alter its capacity to induce GST; (3) prevent chemoresistance in tumour cells. It can be concluded that fermented dietary fibre sources are more potent inhibitors of tumour cell growth than butyrate alone, and also contain ingredients which counteract the undesired positive selection pressures that higher concentrations of butyrate induce in tumour cells.

Clinical research shows that nutritional intervention is necessary to prevent malnutrition in head and neck cancer patients undergoing radiotherapy. The objective of the present study was to assess the value of individually adjusted counselling by a dietitian compared to standard nutritional care (SC). A prospective study, conducted between 2005 and 2007, compared individual dietary counselling (IDC, optimal energy and protein requirement) to SC by an oncology nurse (standard nutritional counselling). Endpoints were weight loss, BMI and malnutrition (5 % weight loss/month) before, during and after the treatment. Thirty-eight patients were included evenly distributed over two groups. A significant decrease in weight loss was found 2 months after the treatment (P = 0·03) for IDC compared with SC. Malnutrition in patients with IDC decreased over time, while malnutrition increased in patients with SC (P = 0·02). Therefore, early and intensive individualised dietary counselling by a dietitian produces clinically relevant effects in terms of decreasing weight loss and malnutrition compared with SC in patients with head and neck cancer undergoing radiotherapy.

1. The effect of isoenergetic substitution of bran and wholemeal bread for white flour and white bread was investigated in six healthy volunteers in a metabolic unit.

2. A 21 d high-fibre experimental period was preceded and followed by a 14 d control period, so that each experiment lasted 7 weeks. Blood samples were taken on each of the last 3 d and faeces collected (using carmine markers) for the last 6 d of each diet period.

3. Plasma cholesterol, triglycerides and serum calcium concentrations were not altered by the addition of wheat fibre.

4. Wheat fibre caused a significant increase in faecal bulk and frequency. Faecal steroid excretion was the same in the last week of the first control and the high-fibre periods but increased in the subsequent control period.

1. Homogenized and diluted faeces (66.6 g/l) collected from one human source on three different months was incubated with four standard substrates (oat bran, wheat bran, red kidney beans (Phuseolus vulgaris) and guar gum) for 4, 8, 12 and 24 h.

2. Neutral-detergent fibre and organic matter (OM) digestibility measurements and gas production (ml gas/g OM) were influenced by substrate and incubation period but not by day of collection.

3. Production of short-chain fatty acids (SCFA) (mmol/g OM) was a function of substrate and incubation period but not day of collection at 4, 8 and 12 h. Rapidly fermentable substrates such as red kidney beans and guar gum did not ferment beyond 12 h and SCFA values were not different at 24 h.

4. Substrates differed in amount, rate and type of SCFA produced.

5. The results indicate that human faeces collected on different occasions were sufficiently uniform to yield similar in vitro fermentation findings among collections. Therefore, it is concluded that human faecal material is a practical source of micro-organisms to evaluate the fermentation properties of substrates.

Mixed-linkage β-glucans are fermented by the colon microbiota that give rise to SCFA. Propionic and butyric acids have been found to play an important role in colonic health, as well as they may have extraintestinal metabolic effects. The aim of the present study was to investigate how two whole-grain barley varieties differing in dietary fibre and β-glucan content affected caecal SCFA, gut microbiota and some plasma inflammatory markers in rats consuming low-fat (LF) or high-fat (HF) diets. Barley increased the caecal pool of SCFA in rats fed the LF and HF diets compared with those fed the control diet, and the effect was generally dependent on fibre content, an exception was butyric acid in the LF setting. Furthermore, whole-grain barley reduced plasma lipopolysaccharide-binding protein and monocyte chemoattractant protein-1, increased the caecal abundance of Lactobacillus and decreased the Bacteroides fragilis group, but increased the number of Bifidobacterium only when dietary fat was consumed at a low level. Fat content influenced the effects of barley: rats fed the HF diets had a higher caecal pool of acetic and propionic acids, higher concentrations of amino acids and higher amounts of lipids in the portal plasma and liver than rats fed the LF diets; however, less amounts of butyric acid were generally formed. Interestingly, there was an increase in the caecal abundance of Akkermansia and the caecal pool of succinic acid, and a decrease in the proportion of Bifidobacterium and the Clostridium leptum group. In summary, whole-grain barley decreased HF diet-induced inflammation, which was possibly related to the formation of SCFA and changes in microbiota composition. High β-glucan content in the diet was associated with reduced plasma cholesterol levels.

Male 1-d-old broilers (n 920) were given 0, 200, 400, 600, 800, 1000 and 1200 U microbial pbytase/kg diet in combination with 2·0, 2·7 or 3·4 g non-phytate P (nP)/kg or 4·0, 5·1 or 5·8 g total P (tP)/kg in a 21 d trial to assess the effectiveness of phytase in a maize–soyabean-meal diet. In addition to the above twenty-one diets, a positive control P diet supplied 4·5 g nP/kg, 6·9 g tP/kg and 10 g Ca/kg. The basal diet contained 230g crude protein/kg, 8·8 g Ca/kg, 4·4 g tP/Fg and 2/0 g nP/kg. Defluorinated phosphate and limestone were used to supply P and Ca. A Ca:tP ratio of 2:l was maintained except in the positive control diet which had a ratio of 1·45: 1. Phytase additions linearly increased (P < 0·01) body-weight (SW) gain, feed intake, toe ash percentage, and apparent retention (% of intake) or total amount (g/bird) of retained Ca and P, and linearly decreased (P < 0·01) P excretion (g/kg of DM intake) at each level of nP with the magnitude of the response inversely related to the level of nP. Above-normal mortality was only observed in the group receiving 2·0 g nP/kg diet without phytase. Adding nP linearly increased (P < 0·01) BW gain, feed intake, toe ash percentage, Ca retention, total amount (g/bird) of P retained, and P excretion, and iinearly decreased (P < 0·01) apparent retention (%) of P. Derived linear and non-linear equations for BW gain and toe ash percentage at the two lower nP levels, 2·0 and 2·7 g/kg, were used to calculate P equivalency value of microbial phytase. The results show that 939 U microbial phytase is equivalent to 1 g P from defluorinated phosphate in broilers fed on maize–soyabean-meal diets. The amount of P released per 100 U phytase decreased as the total amount of phytase increased.

1. The present paper reports the effects on rumen fermentation and plasma metabolites and hormones of giving fixed rations of hay and high-cereal concentrates at different meal frequencies to lactating cows. In Expt 1 the total ration was given in two and twenty-four meals daily and in Expts 2–4 the concentrates were given in two and five or six meals and the hay in two meals daily. The diets contained 600–920 g concentrates/kg.

2. In Expt I, minimum rumen pH was higher but mean pH was lower when cows were given their ration in twenty-four meals/d rather than two meals/d.

3. In all the experiments, the effects of increased meal frequency on the molar proportions of rumen volatile fatty acids (VFA) were small and not significant, although there was a general tendency for the proportion of acetic acid to increase and that of propionic acid to fall. Increasing the proportion of concentrates in the diet reduced the proportion of acetic acid and increased the proportions of propionic and n-valeric acids.

4. In Expt 3, more frequent feeding was found to reduce the concentration of non-esterified fatty acids in the blood, but changes in other metabolites were small and not significant. Increasing the proportion of concentrates in the diet reduced the concentrations of acetic acid and 3-hydroxybutyric acid and increased the concentrations of propionic acid and glucose.

5. The mean daily concentration of insulin in the blood was reduced by more frequent feeding of the higher-concentrate diet but not of the lower-concentrate diet. The concentration of glucagon also tended to fall with more frequent feeding. Increasing the proportion of concentrates in the diet increased the concentration of insulin.

6. More frequent feeding reduced the depression in milk-fat concentration caused by feeding the low-roughage diets. About three-quarters of the variation in milk-fat concentration could be related to changes in rumen VFA proportions, but the relations for the two meal frequencies had different intercepts although similar curves. The results suggest that milk-fat depression on low-roughage diets with twice-daily feeding was due to a change in rumen VFA proportions accompanied by elevated plasma insulin concentrations. The improvement in milk-fat concentration due to more frequent feeding could be explained partly by the small change in rumen VFA proportions and partly by a reduction in mean plasma insulin concentrations, but these mechanisms did not fully account for the milk-fat responses observed.

Hydroxytyrosol (HT) is a major polyphenolic compound found in olive oil with reported anti-cancer and anti-inflammatory activities. However, the neuroprotective effect of HT on type 2 diabetes remains unknown. In the present study, db/db mice and SH-SY-5Y neuroblastoma cells were used to evaluate the neuroprotective effects of HT. After 8 weeks of HT administration at doses of 10 and 50 mg/kg, expression levels of the mitochondrial respiratory chain complexes I/II/IV and the activity of complex I were significantly elevated in the brain of db/db mice. Likewise, targets of the antioxidative transcription factor nuclear factor erythroid 2 related factor 2 including p62 (sequestosome-1), haeme oxygenase 1 (HO-1), and superoxide dismutases 1 and 2 increased, and protein oxidation significantly decreased. HT treatment was also found to activate AMP-activated protein kinase (AMPK), sirtuin 1 and PPARγ coactivator-1α, which constitute an energy-sensing protein network known to regulate mitochondrial function and oxidative stress responses. Meanwhile, neuronal survival indicated by neuron marker expression levels including activity-regulated cytoskeleton-associated protein, N-methyl-d-aspartate receptor and nerve growth factor was significantly improved by HT administration. Additionally, in a high glucose-induced neuronal cell damage model, HT effectively increased mitochondrial complex IV and HO-1 expression through activating AMPK pathway, followed by the prevention of high glucose-induced production of reactive oxygen species and declines of cell viability and VO2 capacity. Our observations suggest that HT improves mitochondrial function and reduces oxidative stress potentially through activation of the AMPK pathway in the brain of db/db mice.

The predictive power, for total, vascular, cancer and respiratory mortality, of selected redox-modulatory (vitamin and mineral nutrient) indices measured at baseline, was studied in the British National Diet and Nutrition Survey (community-living subset) of people aged 65 years and over. Mortality status and its primary and underlying causes were recorded for 1054 (mean age 76·6 (sd 7·4) years and 49·0 % female) participants, from the baseline survey in 1994–5 until September 2008. During this interval, 74 % of the male and 62 % of the female participants died. Total mortality was significantly predicted by baseline plasma concentrations (per sd) of vitamin C (hazard ratio (HR) 0·81; 95 % CI 0·74, 0·88), α-carotene (HR 0·90; 95 % CI 0·81, 0·99), Se (HR 0·76; 95 % CI 0·69, 0·84), Zn (HR 0·79; 95 % CI 0·72, 0·87), Cu (HR 1·27; 95 % CI 1·14, 1·42) and Fe (HR 0·81; 95 % CI 0·74, 0·89). Total mortality was also significantly predicted by baseline dietary intakes (per sd) of food energy (HR 0·86; 95 % CI 0·79, 0·94), vitamin C (HR 0·88; 95 % CI 0·80, 0·94), carotenoids (HR 0·89; 95 % CI 0·83, 0·96), Zn (HR 0·89; 95 % CI 0·82, 0·96) and Cu (HR 0·91; 95 % CI 0·84, 1·00). Prediction patterns and significance for primary vascular, cancer and respiratory mortality differed in certain respects, but not fundamentally. Model adjustment for known disease or mortality risk predictors resulted in loss of significance for some of the indices; however, plasma Se and Zn, and food energy remained significant predictors. We conclude that total and primary vascular, cancer and respiratory mortality in older British people of both sexes is predicted by several biochemical indices of redox-modulatory nutrients, some of which may reflect the respondents' acute-phase status at baseline, whereas others may reflect the healthiness of their lifestyle.

Obesity is a strong risk factor for the development of CVD, hypertension and type 2 diabetes. The overall goal of the present pilot study was to feed strawberries, in the form of freeze-dried powder, to obese subjects to determine whether dietary strawberries beneficially altered lipid profiles and reduced blood markers of inflammation compared with a control intervention. A total of twenty healthy subjects (thirteen females and seven males) aged between 20 and 50 years with a BMI between 30 and 40 kg/m2 completed the present 7-week double-blind, randomised, cross-over trial. Each subject received a prepared diet 7 d/week for 7 weeks consisting of approximately 35 % of energy from fat, 20 % protein, 45 % carbohydrate and 14 g fibre. Blood was collected on days 1 and 8 for baseline information. After the first week, subjects were randomly assigned to the strawberry powder (equivalent to four servings of frozen strawberries) or control (strawberry-flavoured) intervention for 3 weeks. For the remaining 3 weeks, subjects crossed over to the opposite intervention. Blood was collected again at the end of weeks 3, 4, 6 and 7. A comprehensive chemistry panel, lipid profile analyses and measurement of inflammatory mediators were performed for each blood draw. A 3-week dietary intervention with strawberry powder reduced plasma concentrations of cholesterol and small HDL-cholesterol particles, and increased LDL particle size in obese subjects (P < 0·05). Dietary strawberry powder reduced risk factors for CVD, stroke and diabetes in obese volunteers, suggesting a potential role for strawberries as a dietary means to decrease obesity-related disease.

The influence of sodium fumarate on rumen fermentation was investigated in vitro using batch and semi-continuous cultures of mixed rumen micro-organisms taken from three sheep receiving a basal diet of hay, barley, molasses, fish meal and a mineral–vitamin supplement (500, 299·5, 100, 91 and 9·5 g/kg DM respectively). Batch cultures consisted of 10 ml strained rumen fluid in 40 ml anaerobic buffer containing 200 mg of the same feed given to the sheep. Sodium fumarate was added to achieve a final concentration of 0, 5 or 10 mmol/l, as a result of the addition of 0, 250 or 500 μmol, equivalent to 0, 200 and 400 g/kg feed. CH4 production at 24 h (360 μmol in the control cultures) fell (P < 0·05) by 18 and 22 μmol respectively (SED 7·5). Total gas production was increased by the addition of fumarate without significant accumulation of H2. Substantial increases in acetate production (92 and 194 μmol; SED 26·7, P < 0·01) were accompanied by increases in propionate formation (212 and 396 μmol; SED 13·0, P < 0·001). Longer-term effects of fumarate supplementation on ruminal fermentation and CH4 production were investigated using the rumen simulation technique (Rusitec). Eight vessels were given 20 g basal diet/d, and half of them received a supplement of fumarate (disodium salt) over a period of 19 d. The response to the daily addition of 6·25 mmol sodium fumarate was a decrease in CH4 production of 1·2 mmol (SED 0·39, P < 0·05), equivalent to the consumption of 4·8 mmol H2, and an increase in propionate production of 4·9 mmol (from 10·4 to 15·3 (SED 1·05) mmol/d, P < 0·01). The inhibition of CH4 production did not decline during the period of time that fumarate was added to the vessels. Thus, the decrease in CH4 corresponded well to the fraction of the fumarate that was converted to propionate. Fumarate had no significant (P > 0·05) effect on total bacterial numbers or on the number of methanogenic archaea, but numbers of cellulolytic bacteria were increased (8·8 v. 23·9 (SED 2·49) × 105 per ml, P < 0·01). Fumarate also increased DM digestibility of the basal diet after 48 h incubation (0·476 v. 0·508 (SED 0·0123), P < 0·05). Thus, it was concluded that sodium fumarate may be a useful dietary additive for ruminants, because it diverts some H2 from CH4 production and because it is able to stimulate proliferation of cellulolytic bacteria and digestion of fibre.

Frailty is a state of decreased physical functioning and a significant complication of ageing. We examined frailty, energy and macronutrient intake, biomarkers of nutritional status and food insufficiency in US older adult (age ≥ 60 years) participants of the Third National Health and Nutrition Examination Survey (n 4731). Frailty was defined as meeting ≥ 2 and pre-frailty as meeting one of the following four-item criteria: (1) slow walking; (2) muscular weakness; (3) exhaustion and (4) low physical activity. Intake was assessed by 24 h dietary recall. Food insufficiency was self-reported as ‘sometimes’ or ‘often’ not having enough food to eat. Analyses were adjusted for sex, race, age, smoking, education, income, BMI, other co-morbid conditions and complex survey design. Prevalence of frailty was highest among people who were obese (20·8 %), followed by overweight (18·4 %), normal weight (16·1 %) and lowest among people who were underweight (13·8 %). Independent of BMI, daily energy intake was lowest in people who were frail, followed by pre-frail and highest in people who were not frail (6648 (se 130), 6966 (se 79) and 7280 (se 84) kJ, respectively, P< 0·01). Energy-adjusted macronutrient intakes were similar in people with and without frailty. Frail (adjusted OR (AOR) 4·7; 95 % CI 1·7, 12·7) and pre-frail (AOR 2·1; 95 % CI 0·8, 5·8) people were more likely to report being food insufficient than not frail people. Serum albumin, carotenoids and Se levels were lower in frail adults than not frail adults. Research is needed on targeted interventions to improve nutritional status and food insufficiency among frail older adults, while not necessarily increasing BMI.

1. In a randomized block design, four sheep were given 800 g daily of diets containing: chopped lucerne (L), chopped lucerne–rolled barley (2:1; LB), rolled barley–chopped lucerne (2:1; BL), rolled barley (B); each diet was supplemented with minerals, vitamins and urea as considered necessary. Chromic oxide was included in the diets as a flow marker.

2. Flows of organic matter (OM) and non-ammonia-nitrogen (NAN) to the small intestine (SI) were measured and microbial protein was identified by a 35S-incorporation procedure.

3. OM disappearance in the rumen increased linearly with increasing inclusion of barley in the diet but there was no significant change in microbial NAN flow to the SI so that the yield of microbial NAN (g)/kg fermented OM (FOM) decreased from 29.6 (diet L) to 22.7 (diet B). Changes in the energetic efficiency of microbial protein synthesis appeared to be unrelated to alterations in rumen fluid volatile fatty acid (VFA) proportions or in rumen fluid dilution rate (D).

4. The degradability of dietary protein (non-urea-N), estimated using the 35S procedure, was 0.72, 0.76, 0.86 and 0.86 for diets L, LB, BL and B respectively. Similar values were obtained from concurrent polyester-bag experiments when the fractional outflow rate of undergraded protein from the rumen (k) was assumed to be 0.046.

The present study was conducted to investigate the effects of dietary fructo-oligosaccharide (FOS) (0, 1, 2 and 3 %) supplementation on the growth performance, haemato-immunological parameters, cultivable autochthonous (non-adherent) intestinal microbiota and stress resistance of common carp (Cyprinus carpio) fry (3·23 (sem 0·14) g). These parameters were measured after feeding the carp fry with the experimental diets for 7 weeks. Dietary FOS supplementation had no significant effects on the growth performance and food intake of carp fry compared with the control treatment. It also had no significant effects on the following haematological parameters: erythrocyte count; leucocyte counts (WBC); haematocrit; Hb; mean corpuscular volume; mean corpuscular Hb content; mean corpuscular Hb concentration. However, WBC and respiratory burst activity were significantly affected by dietary FOS supplementation. Evaluation of the cultivable autochthonous intestinal microbiota revealed a significant increase in the levels of total viable heterotrophic aerobic bacteria and lactic acid bacteria in fish fed diets supplemented with 2 and 3 % FOS. Furthermore, dietary FOS supplementation significantly increased the survival rate and stress resistance of carp fry compared with the control treatment. These results encourage conducting further research on the administration of FOS and other prebiotics in carp fry studies.

Contrary to concerns that fructose may have adverse metabolic effects, there is evidence that small, ‘catalytic’ doses ( ≤ 10 g/meal) of fructose decrease the glycaemic response to high-glycaemic index meals in human subjects. To assess the longer-term effects of ‘catalytic’ doses of fructose, we undertook a meta-analysis of controlled feeding trials. We searched MEDLINE, EMBASE, CINAHL and the Cochrane Library. Analyses included all controlled feeding trials ≥ 7 d featuring ‘catalytic’ fructose doses ( ≤ 36 g/d) in isoenergetic exchange for other carbohydrates. Data were pooled by the generic inverse variance method using random-effects models and expressed as mean differences (MD) with 95 % CI. Heterogeneity was assessed by the Q statistic and quantified by I2. The Heyland Methodological Quality Score assessed study quality. A total of six feeding trials (n 118) met the eligibility criteria. ‘Catalytic’ doses of fructose significantly reduced HbA1c (MD − 0·40, 95 % CI − 0·72, − 0·08) and fasting glucose (MD − 0·25, 95 % CI − 0·44, − 0·07). This benefit was seen in the absence of adverse effects on fasting insulin, body weight, TAG or uric acid. Subgroup and sensitivity analyses showed evidence of effect modification under certain conditions. The small number of trials and their relatively short duration limit the strength of the conclusions. In conclusion, this small meta-analysis shows that ‘catalytic’ fructose doses ( ≤ 36 g/d) may improve glycaemic control without adverse effects on body weight, TAG, insulin and uric acid. There is a need for larger, longer ( ≥ 6 months) trials using ‘catalytic’ fructose to confirm these results.