Evidence of protection against diarrhoea in suckling piglets by a hormone-like protein in the sow's milk

Effects of Dietary Isomaltooligosaccharide Levels on the Gut Microbiota, Immune Function of Sows, and the Diarrhea Rate of Their Offspring

To investigate the effects of dietary isomaltooligosaccharide (IMO) levels on the gut microbiota, immune function of sows, and the diarrhea rate of their offspring, 120 multiparous gestating pig improvement company (PIC) sows with similar body conditions were selected and fed 1 of 6 diets: a basal diet with no supplement (control, CON), or a diet supplemented with 2.5 g/kg, 5.0 g/kg, 10.0 g/kg, 20.0 g/kg, or 40.0 g/kg IMO (IMO1, IMO2, IMO3, IMO4, or IMO5 group, respectively). Results showed that dietary treatments did not affect the reproductive performance and colostrum composition of sows (P > 0.05). However, compared to the CON, IMO reduced the diarrhea rate of suckling piglets (P < 0.05) and improved the concentrations of colostrum IgA, IgG, and IgM (P < 0.05). Moreover, IMO decreased the concentrations of serum D-lactate (D-LA) and lipopolysaccharides (LPS) at farrowing and day 18 of lactation (L18) (P < 0.05). High-throughput pyrosequencing of the 16S rRNA demonstrated that IMO shaped the composition of gut microbiota in different reproductive stages (day 107 of gestation, G107; day 10 of lactation, L10) (P < 0.05). At the genus level, the relative abundance of g_Parabacteroides and g_Slackia in G107 and g_Unclassified_Peptostreptococcaceae, g_Turicibacter, g_Sarcina, and g_Coprococcus in L10 was increased in IMO groups but the g_YRC22 in G107 was decreased in IMO groups relative to the CON group (P < 0.05). Furthermore, the serum D-LA and LPS were negatively correlated with the genus g_Akkermansia and g_Parabacteroides but positively correlated with the genus g_YRC22 and g_Unclassified_Peptostreptococcaceae. Additionally, the colostrum IgA, IgG, and IgM of sows were positively correlated with the genus g_Parabacteroides, g_Sarcina, and g_Coprococcus but negatively correlated with the genus g_YRC22. These findings indicated that IMO could promote the immune activation and had a significant influence in sows' gut microbiota during perinatal period, which may reduce the diarrhea rate of their offspring.

The antisecretory factor: synthesis, anatomical and cellular distribution, and biological action in experimental and clinical studies

The antisecretory factor (AF) is a 41-kDa protein that provides protection against diarrheal diseases and intestinal inflammation. Its cDNA has been cloned and sequenced. AF is highly potent, with 10(-12) mol of recombinant AF being sufficient to counteract experimentally induced diarrhea in rat. The antisecretory activity is exerted by a peptide located between positions 35 and 50 of the AF sequence. Synthetic peptides based on this sequence are promising candidates for drugs to counteract intestinal hypersecretion, as well as imbalances of fluid transport in other body compartments. AF probably exerts its effects via nerves; AF immediately and potently inhibits ion transport across isolated nerve membranes from Deiters' cells. Immunocytochemistry has shown that AF is present in most tissues in the body, and in situ nucleic acid hybridization has shown that cells that store AF are also capable of AF synthesis. The endogenous plasma level of AF is increased by enterotoxins and by certain food constituents such as hydrothermally processed cereals. These cereals significantly improve clinical performance in patients suffering from inflammatory bowel diseases. AF-enhancing food also protects domestic animals against diarrheal diseases, and such feed has been used successfully in Swedish swine farming for the past 10 years. Increased understanding of AF action might result in expanded clinical applications and confirm that AF is an important regulator of homeostasis.

Breast feeding and the intestinal microflora of the infant--implications for protection against infectious diseases

Human breast milk contains an array of factors with anti-infectious potential, such as immunoglobulins (especially secretory IgA), oligosaccharides and glycoproteins with anti-adhesive capacity, and cytokines. Breast-feeding is associated with protection from the following infections or infection-related conditions: gastroenteritis, upper and lower respiratory tract infection, acute otitis media, urinary tract infection, neonatal septicaemia and necrotizing enterocolitis. Some of the protective effects may derive from an altered mucosal colonization pattern in the breast-fed infant. In other instances breast-fed infants develop less symptoms to the same microbe which causes disease in the bottle-fed infant. An example of an altered colonization pattern is that breast-fed infants have less P-fimbriated, but more type 1-fimbriated E. coli. This may protect against urinary tract infection in the breast-fed infant since P. fimbriae are the major virulence factor for urinary tract infection. An example of changed consequences of the same microbial colonization is that secretory IgA in the breast-milk protects very efficiently from translocation of intestinal bacteria across the gut mucosa by coating intestinal bacteria and blocking their interaction with the epithelium. This mechanism may protect the infant from septicaemia of gut origin and, possibly, necrotizing enterocolitis. Breast-milk is also highly anti-inflammatogenic and contains hormone like factors which counteract diarrhea. Thus, breast-fed infants may be colonized by recognized diarrheal pathogens and still remain healthy. Due to a less virulent intestinal microflora and decreased translocation breast-fed infants will obtain less stimuli for the gut immune system, resulting, in e.g., lower salivary IgA antibody titres.

Concentrations of antisecretory factor in eggs and in chicken blood plasma

1. In the present study, the concentration of antisecretory factor (ASF), a lectin with hormone-like properties, and with the capacity to regulate water and electrolyte transport in the small intestine, was higher in hen's egg yolk than in egg white (1.20 v. 0.46 units/ml). 2. The blood plasma concentrations of ASF activity were higher in d-old chicks (1.03 units/ml) than in 7-d-old (0.42 units/ml) or 21-d-old birds (0.18 units/ml); the contents were found to be high again in 35-d-old chickens, but to have decreased by 60 to 90% after transport to slaughter 1 day later. 3. The amount of ASF activity was lower in two groups of chickens manifesting patent loose droppings at slaughter (0.15 units/ml in one group, and 0.08 units/ml in the other), than in two groups with normal faecal consistency (0.65 units/ml in one group, and 0.72 units/ml in the other). 4. The results demonstrate the presence of ASF in eggs, and a variation of ASF activity in chickens blood plasma in relation to age, stress and faecal consistency. The interpretation of these data suggests a regulatory influence of ASF on chicken intestinal transport of water.

Plasma level of antisecretory factor (ASF) and its relation to post-weaning diarrhoea in piglets

Antisecretory factor (ASF) is a regulatory peptide which counteracts diarrhoea in the pig; ASF is rapidly absorbed from the pig intestine, and significantly reduces the incidence of neonatal diarrhoea in the suckling offspring. ASF is synthesized in the central nervous system, and released to the blood stream via the pituitary gland. In two different experiments (n = 8 and n = 4), the blood concentration of ASF was followed in 5-weeks old piglets from day 7 before weaning up to day 12 days after weaning. In both experiments ASF concentrations were significantly (p < 0.01) lower on day three post-weaning, than either before weaning or on days 7 and 12 post-weaning. In another experiment, where plasma ASF activity was determined in relation to clinical signs of diarrhoea seven days post-weaning, it was found to be 0.87 +/- 0.08 units/ml (mean +/- SEM) in healthy weaners (n = 15), but only 0.22 +/- 0.05 units/ml in piglets suffering from diarrhoea (n = 15), the difference being significant. The faecal flora both of healthy weaners and of their matched controls suffering from diarrhoea were subjected to bacteriological examination before and after weaning, and found to be similar in both groups, namely a mixture of aerobic and anaerobic Gram negative rods, Campylobacter jejuni, Staphylococcus aureus/epidermidis, and Enterococcus faecalis. No particular pathogen was predominant in any of the diseased animals.

The pathogenesis of the post-weaning syndrome in weaned piglets: a review

This review deals with the pathogenesis of the post-weaning syndrome. This syndrome includes post-weaning diarrhoea (PWD), oedema disease (OD) and endotoxin shock (ES). The role of different enteropathogenic Escherichia coli bacteria and some other predisposing factors relating to this post-weaning syndrome (PWS) are discussed. Based on intestinal pathophysiological mechanisms, some suggestions for the prevention of PWS and prospects for future research are given.

Clostridium difficile toxin A induces a specific antisecretory factor which protects against intestinal mucosal damage

Peroral challenge with toxin A from Clostridium difficile induced the formation of antisecretory factor in rats. The animals were given 100 micrograms of the toxin, which was followed by a pronounced diarrhoea and by the appearance of antisecretory factor in the pituitary gland. In electrofocusing, the induced antisecretory factor separated in two peaks (pI 5.4 and 5.0); both fractions showed a lectin-like binding to agarose. The pI 5.4 fraction inhibited cholera toxin as well as toxin A induced fluid secretion, while pI 5.0 inhibited toxin A induced secretion only. Immunohistochemistry showed that an antisecretory factor of pI 5.0 protected the mucosa from the cytotoxic effect of toxin A, but did not affect the binding of toxin A to the intestinal epithelium. Sodium dodecyl-sulphate-polyacrylamide gel electrophoresis of the pI 5.0 protein showed two major fractions to be present, one of molecular weight 60 kDa, the other of 30 kDa, the latter probably being a degradation product of the former.

Influence of age on antisecretory factor inhibition of enterotoxin action in the pig small intestine

The effect of age on antisecretory factor (ASF) inhibition of cholera toxin (CT) and E. coli STa enterotoxin-induced fluid secretion in pig jejunum was investigated in vivo. Comparison was made between 2 week and 8 week old animals. ASF inhibited (P less than 0.05) CT-induced fluid secretion by up to 90% in the 8 week animals (from 18.4 +/- 5.87 mg/mg loop dry weight to 0.74 +/- 0.54 mg/mg loop dry weight). There was no effect of ASF on CT-secretion in the 14 day pigs suggesting that there is a minimum age before ASF is effective. ASF had no significant effect on net fluid transport after STa challenge in pigs from either age group. However, the predominant action of STa was to inhibit absorption and this would not be affected by ASF.