Effects of torula and brewer's yeast diets in obese and lean mice

Effect of supplemental levels of chromium picolinate on the growth performance, serum traits, carcass characteristics and lipid metabolism of growing-finishing pigs

This study investigated the effect of chromium picolinate supplementation on growth performance, carcass characteristics and lipid metabolism of growing-finishing pigs. Sixty Landrace ✕ Yorkshire ✕ Duroc (LYD) pigs with a mean initial body weight of 46·65 (s.e. 6·72) kg were randomly allocated into three groups with two replicates. They were supplemented with 0 , 200, or 400 μg/kg (ppb) chromium in the organic form of chromium picolinate for 90 days. Supplementation with chromium picolinate in the pigs’ ration improved their growth performance, enhanced average daily gain (P < 0·05), and increased their food consumption, especially in the 200 ppb group ( P > 0·05). Chromium picolinate supplementation also improved carcass characteristics, as the average back fat thickness was reduced and the loin-eye area was enhanced ( P < 0·05). The serum chromium concentration in the chromium picolinate supplemented groups was approximately twice that of the controls ( P < 0·05). Supplementation with chromium also markedly reduced serum total cholesterol, triacylglycerol (TG) and urea concentrations in the pig serum ( P < 0·05). Serum insulin was significantly decreased in the 400 ppb group, while serum glucose was decreased in the 200 ppb group ( P < 0·05). Very low density lipoprotein (VLDL) was reduced and low density lipoprotein (LDL) was increased in the chromium supplementation group. Meanwhile, the high density lipoprotein-cholesterol and VLDL-cholesterol were markedly increased, while LDL-cholesterol was significantly diminished ( P < 0·05) in the 200 ppb group. The adipocyte diameter and volume in the chromium-supplemented groups tended to be larger than in the control ( P = 0·07). In vitro studies indicated that incorporation of [u, 14C]glucose into total lipids (P < 0·05) was increased by chromium supplementation. However, there were no lipolysis differences among the groups (P > 0·05). The carcasses of the pigs that received the chromium supplemented ration contained less oleic acid (C18 : 1) and total unsaturated fatty acids (P < 0·05). On the other hand, the total saturated fatty acid content was higher than that of the controls (P < 0·05). Results in this study demonstrate that chromium picolinate supplementation in pigs has several beneficial effects.

Effect of different protein and limiting amino acid levels coupled with a supplement of chromium picolinate on lipid metabolism and carcass characteristics of pigs

This study investigated the response of different dietary protein and limiting amino acid concentrations coupled with a supplement of chromium in growing-finishing pigs. Sixty Landrace × Yorkshire × Duroc bacon type pigs with an initial live weight of 33·08 (s.d. 4·80) kg were randomly assigned into six groups with an equal number of males and females. They were given diets containing proportionately 1·0, 1·1 or 1·2 of the National Research Council recommendation of crude protein and limiting amino acid (lysine and methionine) levels and coupled with supplementing chromium at 0 or 200 ng/kg in the form of chromium picolinate (Crpic). The experiment was completed when the pigs' live weight reached 120 kg. Experiment results indicated that different nutrient levels or Crpic supplement did not significantly affect pig growth (P > 0·05). However, both nutrient levels and Crpic supplementation increased y-globulin concentration (P < 0·05). In addition, Crpic supplement not only significantly reduced the backfat thickness, serum insulin level and VLDL-C + LDL-C concentration (P < 0·05) but also increased the loin-eye area and HDL-C concentration of pigs (P < 0·05). On the other hand, the particle sizes of HDL and VLDL were decreased and increased (P < 0·05), respectively. In addition, Crpic supplement increased the activities of adipose tissue lipogenesis related enzymes such as fatty acid synthetase, ATP-citrate cleavage enzyme and NADP-malic dehydrogenase (P < 0·05 to 0·001). In a similar manner, Crpic supplement increased the activities of adipose tissue lipoprotein lipase and serum lecithin-cholesterol acyltransferase (P < 0·05). However, the interactions of nutrient levels × Crpic supplementation were insignificant (P > 0·05). Results in this study demonstrated that chromium picolinate supplement created a beneficial effect but supplements of chromium coupled with high dietary protein and limiting amino acid levels were unnecessary for bacon-type pigs.

Effects of brewer's yeast on glucose tolerance and serum lipids in Chinese adults

This study was designed to investigate the supplemental effects of brewer's yeast on serum glucose and lipids in Chinese adults. Twenty-two participants (8 males and 14 females) were recruited from Pingtung city. Mean age of the group was 51 yr, and fasting values of total cholesterol and glucose were from 3.21 to 6.90 and 4.3 to 6.2 mmol/L, respectively. Before supplementation, a 75 g oral glucose load was administered after an overnight (9 h) fast. Blood was drawn before and at 30, 60, 90, and 120 min after the glucose load. The subjects were randomly assigned into either brewer's yeast or torula yeast group and consumed 10 g yeast powder daily for 12 wk. Brewer's yeast demonstrated a beneficial effect on decreasing serum triacylglycerol values (p < 0.05). The brewer's yeast supplemented group had an increment at 0 min (p < 0.01) and significant decrements at 60 (p < 0.05) and 90 (p < 0.01) min of oral glucose tolerance test (OGTT). However, after 12-wk supplementation, torula yeast increased glucose values at both 0 and 30 min (p < 0.05) after a glucose load. Brewer's yeast and torula yeast addition significantly altered glucose concentrations at 60 min after the glucose dosage (p < 0.05). Brewer's yeast had significantly decreasing effects on insulin output both at 90 (p < 0.05) and 120 min (p < 0.01) after the glucose load. Likewise, serum insulin contents decreased at 90 min (p < 0.01) after supplementation in the group given torula yeast. Brewer's yeast supplementation had beneficial effects both on serum triacylglycerol and on 60-min and 90-min glucose values of OGTT.