Identification of beer bitter acids regulating mechanisms of gastric acid secretion

Beer, one of the most consumed beverages worldwide, has been shown to stimulate gastric acid secretion. Although organic acids, formed by fermentation of glucose, are known to be stimulants of gastric acid secretion, very little is known about the effects of different types of beer or the active constituents thereof. In the present study, we compared the effects of different beers on mechanisms of gastric acid secretion. To investigate compound-specific effects on mechanisms of gastric acid secretion, organic acids and bitter compounds were quantified by HPLC-DAD and UPLC-MS/MS and tested in human gastric cancer cells (HGT-1) by means of a pH-sensitive fluorescent dye which determines the intracellular pH as an indicator of proton secretion. The expression of relevant genes, coding the H(+)/K(+)-ATPase, ATP4A, the histamine receptor, HRH2, the acetylcholine receptor, CHRM3, and the somatostatin receptor, SSTR2, was determined by qPCR. Ethanol and the organic acids succinic acid, malic acid, and citric acid were demonstrated to contribute to some extent to the effect of beer. The bitter acids comprising α-, β-, and iso-α-acids were identified as potential key components promoting gastric acid secretion and up-regulation of CHRM3 gene expression by a maximum factor of 2.01 compared to that of untreated control cells with a correlation to their respective bitterness.     

Effect of sainfoin (Onobrychis viciifolia) silage and hay on established populations of Haemonchus contortus and Cooperia curticei in lambs

The objective of the study was to examine the effect of dried and ensiled sainfoin (Onobrychis viciifolia) on established populations of Haemonchus contortus (abomasum) and Cooperia curticei (small intestine) in lambs under controlled conditions. Twenty-four parasite na?ve lambs were inoculated with a single dose of infective larvae of these parasites 28 days prior to the start of the feeding experiment. Twenty-four days post-infection, 4 days prior to the start of the feeding experiment, animals were allocated to four groups according to egg excretion, live weight and sex. Groups A and B received sainfoin hay and control hay, respectively, for 16 days. Groups C and D were fed on sainfoin silage or control silage for the same period. Feeds were offered ad libitum and on the basis of daily refusals were supplemented with concentrate in order to make them isoproteic and isoenergetic. Individual faecal egg counts on a dry matter basis (FECDM) were performed every 3-4 days and faecal cultures and packed cell volume (PCV) measurements were done weekly. After 16 days of experimental feeding, all animals were slaughtered and adult worm populations were determined. The consumption of conserved sainfoin was associated with a reduction of adult H. contortus (47% in the case of hay, P<0.05; 49% in the case of silage, P=0.075) but had little effect on adult C. curticei. Compared to the controls, H. contortus specific FECDM was reduced by 58% (P<0.01) in the sainfoin hay group and by 48% (P=0.075) in the sainfoin silage group. For both sainfoin feeds FECDM specific to C. curticei were significantly decreased when compared to the control feeds (hay 81% and silage 74%, both tests P<0.001). Our data suggest that different mechanisms were responsible for the reduction in FECDM in response to feeding tanniferous fodder. For H. contortus, the decrease seemed to be due to a nematocidal effect towards adult H. contortus. In contrast for C. curticei, the reduction in FECDM appeared to be a result of a reduced per capita fecundity. For both, hay and silage, an antiparasitic effect could be shown, offering promising perspectives for the use of conserved tanniferous fodder as a complementary control approach against GIN.     

Effect of different levels of mannan-oligosaccharide supplementation on some immunological variables in weaned piglets

The effect of different doses of mannan-oligosaccharide (MOS) on specific and non-specific immune responses was studied in piglets, weaned at 28 days. A total of 58 piglets were used in six groups. Five groups were fed 0, 1, 2, 4 g MOS product per kg diet or with growth promoting antibiotics and immunized by inactivated Aujeszky’s disease virus (AyV) vaccine at week 1 and 3 of the experiment (35 and 49 days). A sixth group, receiving the same non-supplemented diets was not immunized. Blood samples for lymphocyte stimulation (LST) and AyV neutralization (VN) tests were taken from all pigs on the first day of the experiment and at weekly intervals for 5 weeks. At week 8, the immunized piglets were infected orally with transmissible gastroenteritis virus. All piglets were weighed and slaughtered at week 10, digesta from small intestine were collected and tested for the presence of secretory (s)IgA. Feeding MOS supplementation resulted in enhanced specific and non-specific immune responses, however, a regressive dose-response of MOS was observed. Both the specific cellular (LST) and humoral responses (VN) were enhanced after 2 weeks of feeding 1 g/kg MOS and significantly differed from the antibiotic positive control. The same tendency was detected in case of the non-specific LSTs, although these started some weeks later showing significant differences by the fifth week. Higher doses of MOS had no further beneficial effect on systemic immunity. In addition, 1 g/kg MOS supplementation group also showed some advantage in local immune responsiveness. Therefore, based on the studied immune variables, 1 g/kg MOS product is suggested in the diet of weaned piglets.