Use of Megasphaera elsdenii NCIMB41125 as a probiotic for early-lactation dairy cows: effects on rumen pH and fermentation patterns

Multiparous rumen-fistulated Holstein cows were fed, from d 1 to 28 post-calving, an ad libitum TMR containing (g/kg DM) grass silage (196), corn silage (196), wheat (277), soybean meal (100), and other feeds (231) with CP, NDF, starch and water soluble carbohydrate concentrations of 176, 260, 299 and 39 g/kg DM respectively and ME of 12.2 MJ/kg DM. Treatments consisting of a minimum of 1010 cfu Megasphaera elsdenii NCIMB 41125 in 250 ml solution (MEGA) or 250 ml of autoclaved M. elsdenii (CONT) were administered via the rumen cannula on d 3 and 12 of lactation (n=7 per treatment). Mid-rumen pH was measured every 15 minutes and eating and ruminating behavior was recorded for 24 h on d 2, 4, 6, 8, 11, 13, 15, 17, 22 and 28. Rumen fluid for VFA and lactic acid (LA) analysis was collected at 11 timepoints on each of d 2, 4, 6, 13 and 15. Data were analysed as repeated measures using the Glimmix (LA data) or Mixed (all other data) procedures of SAS with previous 305 d milk yield and d 2 measurements as covariates where appropriate. Milk yield was higher (CONT 43.0 vs MEGA 45.4 ±0.75 kg/d, P=0.051) and fat concentration was lower (CONT 45.6 vs MEGA 40.4 ±1.05 g/kg, P=0.005) in cows that received MEGA. Time spent eating (263 ±15 min/d) and ruminating (571 ±13 min/d), DM intake (18.4 ±0.74 kg/d), proportion of each 24 h period with rumen pH below 5.6 (3.69 ±0.94 h) and LA concentrations (2.00 mM) were similar (P>0.327) across treatments. Ruminal total VFA concentration (104 ±3 mM) was similar (P=0.404) across treatments, but a shift from acetate (CONT 551 vs MEGA 524 ±14 mmol/mol VFA, P=0.161) to propionate production (CONT 249 vs MEGA 275 ±11 mmol/mol VFA, P=0.099) meant that the acetate:propionate ratio (CONT 2.33 vs MEGA 1.94 ±0.15) was reduced (P=0.072) in cows that received MEGA. This study provides evidence that supplementation of early lactation dairy cows with MEGA alters rumen fermentation patterns in favour of propionate, with potential benefits for animal health and productivity.

Second meal effect: modified sham feeding does not provoke the release of stored triacylglycerol from a previous high-fat meal

The present study was carried out to determine whether cephalic stimulation, associated with eating a meal, was sufficient stimulus to provoke the release of stored triacylglycerol (TAG) from a previous high-fat meal. Ten subjects were studied on three separate occasions. Following a 12 h overnight fast, subjects were given a standard mixed test meal which contained 56 g fat. Blood samples were taken before the meal and for 5 h after the meal when the subjects were randomly allocated to receive either water (control) or were modified sham fed a low-fat (6 g fat) or moderate-fat (38 g fat) meal. Blood samples were collected for a further 3 h. Compared with the control, modified sham feeding a low- or moderate-fat meal did not provoke an early entry of TAG, analysed in either plasma or TAG-rich lipoprotein (TRL) fraction (density ,1´006 kg/l). The TRL-retinyl ester data showed similar findings. A cephalic phase secretion of pancreatic polypeptide, without a significant increase in cholecystokinin levels, was observed on modified sham feeding. Although these data indicate that modified sham feeding was carried out successfully, analysis of the fat content of the expectorant showed that our subjects may have accidentally ingested a small amount of fat (0´7 g for the low-fat meal and 2´4 g for the moderate-fat meal). Nevertheless, an early TAG peak following modified sham feeding was not demonstrated in the present study, suggesting that significant ingestion of food, and not just orosensory stimulation, is necessary to provoke the release of any TAG stored from a previous meal.

The effect of the daily intake of inulin on fasting lipid, insulin and glucose concentrations in middle-aged men and women

The present study was carried out to examine the effect of the daily intake of 10 g inulin on fasting blood lipid, glucose and insulin levels in healthy middle-aged men and women with moderately raised total plasma cholesterol (TC) and triacylglycerol (TAG) levels. This study was a doubleblind randomized placebo-controlled parallel study in which fifty-four middle-aged subjects received either inulin or placebo for a period of 8 weeks. Fasting blood samples were collected before the supplementation period (baseline samples 1 and 2, separated by 1 week) and at weeks 4 and 8, with a follow-up at week 12. Compared with baseline values, insulin concentrations were significantly lower at 4 weeks (P,0×01) in the inulin group. There was a trend for TAG values, compared with baseline, to be lower in the inulin group at 8 weeks (P,0×08) returning to baseline concentrations at week 12. On comparison of the inulin and placebo groups, the fasting TAG responses over the 8-week test period were shown to be significantly different (P,0×05, repeated measures ANOVA), which was largely due to lower plasma TAG levels in the inulin group at week 8. The percentage change in TAG levels in the inulin group during the 8-week study was shown to correlate with the initial TAG level of the subjects (rs -0×499, P = 0×004). We therefore conclude that the daily addition of 10 g inulin to the diet significantly reduced fasting insulin concentrations during the 8-week test period and resulted in lower plasma TAG levels, particularly in subjects in whom fasting TAG levels were greater than 1×5 mmol/l. These data support findings from animal studies that fructans influence the formation and/or degradation of TAG-rich lipoprotein particles, and the insulin data are also consistent with recent studies showing attenuation of insulin levels in fructan-treated rats.

Effect of long-term olive oil dietary intervention on postprandial triacylglycerol and factor VII metabolism

Although the beneficial effects of Mediterranean-type diets, which are rich in olive oil, a good source of monounsaturated fatty acids (MUFAs), are generally accepted, little is known about the effects of long-term dietary MUFA intake on postprandial lipoprotein metabolism and hemostasis. This study used a single-blind, randomized, crossover design to investigate the relative effects of a long-term dietary olive oil intervention and a control [saturated fatty acid (SFA)-enriched] diet on postprandial triacylglycerol metabolism and factor VII activity. The postprandial response to a standard test meal was investigated in 23 healthy men who adhered to both diets for 8 wk. cis-MUFAs were successfully substituted for SFAs in the MUFA diet without affecting total dietary fat or energy intakes. The long-term dietary MUFA intervention significantly reduced plasma and LDL-cholesterol concentrations (P = 0.01). Postprandial triacylglycerol concentrations were significantly greater in the early postprandial period after the MUFA diet (P = 0.003). Postprandial factor VII activation and the concentration of the factor VII antigen were significantly lower after the MUFA diet (P = 0.04 and P = 0 006, respectively). This study showed that isoenergetic substitution of MUFAs for SFAs reduces plasma cholesterol and reduces the degree of postprandial factor VII activation. The alterations in the postprandial triacylglycerol response suggest a greater rate of dietary fat absorption and postprandial triacylglycerol metabolism after a diet rich in MUFAs. This study presents new insights into the biochemical basis of the beneficial effects associated with long-term dietary MUFA consumption, which may explain the lower rates of coronary mortality in Mediterranean regions.

Meal frequency; does it determine postprandial lipaemia?

OBJECTIVE: To determine the effect of altering meal frequency on postprandial lipaemia and associated parameters. DESIGN: A randomized open cross over study to examine the programming effects of altering meal frequency. A standard test meal was given on three occasions following: (i) the normal diet; (ii) a period of two weeks on a nibbling and (iii) a period of two weeks on a gorging diet. SETTING: Free living subjects associated with the University of Surrey. SUBJECTS: Eleven female volunteers (age 22 +/- 0.89 y) were recruited. INTERVENTIONS: The subjects were requested to consume the same foods on either a nibbling diet (12 meals per day) or a gorging diet (three meals per day) for a period of two weeks. The standard test meal containing 80 g fat, 63 g carbohydrate and 20 g protein was administered on the day prior to the dietary intervention and on the day following each period of intervention. MAJOR OUTCOME MEASURES: Fasting and postprandial blood samples were taken for the analysis of plasma triacylglycerol, non-esterified fatty acids, glucose, immunoreactive insulin, glucose-dependent insulinotropic polypeptide levels (GIP) and glucagon-like peptide (GLP-1), fasting total, low density lipoprotein (LDL)- and high density lipoprotein (HDL)-cholesterol concentrations and postheparin lipoprotein lipase (LPL) activity measurements. Plasma paracetamol was measured following administration of a 1.5 g paracetamol load with the meal as an index of gastric emptying. RESULTS: The compliance to the two dietary regimes was high and there were no significant differences between the nutrient intakes on the two intervention diets. There were no significant differences in fasting or postprandial plasma concentrations of triacylglycerol, non-esterified fatty acids, glucose, immunoreactive insulin, GIP and GLP-1 levels, in response to the standard test meal following the nibbling or gorging dietary regimes. There were no significant differences in fasting total or LDL-cholesterol concentrations, or in the 15 min postheparin lipoprotein lipase activity measurements. There was a significant increase in HDL-cholesterol in the subjects following the gorging diet compared to the nibbling diet. DISCUSSION: The results suggest that previous meal frequency for a period of two weeks in young healthy women does not alter the fasting or postprandial lipid or hormonal response to a standard high fat meal. CONCLUSIONS: The findings of this study did not confirm the previous studies which suggested that nibbling is beneficial in reducing the concentrations of lipid and hormones. The rigorous control of diet content and composition in the present study compared with others, suggest reported effects of meal frequency may be due to unintentional alteration in nutrient and energy intake in previous studies.

Postprandial lipid and hormone responses to meals of varying fat contents: modulatory role of lipoprotein lipase?

OBJECTIVE: Substrate and hormone responses to meals of differing fat content were evaluated in normal subjects in order to investigate mechanisms underlying the regulation of postprandial lipoprotein concentration. DESIGN: A randomised cross-over study with three different meals on three occasions. SETTING: Free-living subjects associated with Surrey University. SUBJECTS: Ten male volunteers (aged 18-23 years) were recruited. INTERVENTIONS: Three test meals containing 20, 40 or 80 g fat but identical carbohydrate and protein content were randomly allocated to volunteers. MAJOR OUTCOME MEASURES: Pre- and postprandial blood samples were taken for the analysis of plasma triacylglycerol, non-esterified fatty acids, glucose, immunoreactive insulin and glucose-dependent insulinotrophic polypeptide levels and postheparin lipoprotein lipase activity measurements. RESULTS: Peak triacylglycerol concentrations and lipoprotein lipase activity measurements were significantly higher following the 80 g than the 20 g fat meal (P = 0.009 and P = 0.049 respectively). Areas under the glucose-dependent insulinotrophic polypeptide time-response concentration curves were significantly higher following the 80 g compared with the 20 g fat meal (P = 0.04), but no differences in insulin response to the meals were seen. The 30-360 min decrease in the non-esterified fatty acid concentration was less following the 80 g than the 20 g meal (P = 0.001). CONCLUSIONS: The results suggest that glucose-dependent insulinotrophic polypeptide may mediate increased lipoprotein lipase activity in response to fat-containing meals and may play a role in circulating lipoprotein homeostasis. This mechanism may be overloaded with high fat meals with adverse consequences on circulating triacylglycerol and NEFA concentrations.

Effect of intensive vs. free range production on the fat and fatty acid composition of whole birds and edible portions of retail chickens in the UK

The primary objective was to compare the fat and fatty acid contents of cooked retail chickens from intensive and free range systems. Total fat comprised approximately 14, 2.5, 8, 9 and 15 g/100 g cooked weight in whole birds, skinless breast, breast with skin, skinless leg and leg meat with skin, respectively, with no effect of intensive compared with free range systems. Free range breast and leg meat contained significantly less polyunsaturated fatty acids (n-6 and n-3) than did those from intensive rearing and had a consistently higher n-6/n-3 ratio (6.0 vs. 7.9). Generally, the concentrations of long chain n-3 fatty acids were considerably lower than those reported in earlier research studies. Overall, there was no evidence that meat from free range chickens had a fatty acid profile that would be classified as healthier than that from intensively reared birds and indeed, in some aspects, the opposite was the case. (C) 2011 Elsevier Ltd. All rights reserved.

Thermogenic and metabolic consequences of thyroid hormone treatment in brown and white adipose tissue

Male rats were treated with triiodothyronine in the drinking water for 12 days. In vitro rates of isoprenaline stimulated lipolysis were significantly greater in brown but not white adipose tissue. Rates of [14C]glucose incorporation into triacylglycerols were significantly reduced in BAT (brown adipose tissue) and WAT (white adipose tissue) under basal and isoprenaline stimulated conditions. In a second experiment, hyperthyroid animals showed impaired weight gain, despite increased food intake during 19 days' treatment. Energy expenditure on days 5 and 12, and BAT core temperature differences (TBAT - TCORE) on day 19, were significantly greater than in control animals. Epididymal white fat pad weight was reduced and interscapular brown fat pad weight increased by triiodothyronine treatment.