The effect of maternal antibiotic use in sows on intestinal development in offspring.

The objective of this study is to investigate the effect of a maternal antibiotic administration during the last week of gestation on the early life intestinal development in neonatal piglets. Colonization of the gut with bacteria starts during birth and plays a major role in the intestinal and immunological development of the intestine. We demonstrate that maternal interventions induced changes in the sows (n = 6 to 8 per treatment) fecal microbiota diversity around birth (P < 0.001, day 1). Whole-genome microarray analysis in small intestinal samples of 1-d old piglets (n = 6 to 8 per treatment) showed significantly expressed genes (Padj < 0.05) which were involved in processes of tight junction formation and immunoglobulin production. Furthermore, when performing morphometry analysis, the number of goblet cells in jejunum was significantly (P < 0.001) lower in piglets from amoxicillin administered sows compared with the respective control piglets. Both significantly expressed genes (Padj < 0.05) and significant morphometry data (jejunum P < 0.05 and ileum P < 0.01) indicate that the crypts of piglets from amoxicillin administered sows deepen around weaning (day 26) as an effect of the amoxicillin administration in sows. The latter might imply that the intestinal development of piglets was delayed by maternal antibiotic administration. Taken together, these results show that maternally oral antibiotic administration changes in early life can affect intestinal development of the offspring piglets for a period of at least 5 wk after the maternal antibiotic administration was finished. These results show that modulation of the neonatal intestine is possible by maternal interventions.

Effects of a feed additive blend on broilers challenged with heat stress.

We evaluated a blend of medium-chain fatty acids (MCFA), organic acids, and a polyphenol antioxidant on gut integrity. Eighty Ross Broilers were exposed to 20-22°C (control - normothermic) or to 35-39.5°C (heat stress) for eight hours a day for a period of 1 or 5 days. Birds were fed a standard diet, or a diet supplemented with the test blend. Thereafter, birds were euthanized, and intestinal sections were excised for morphological, morphometric and gene expression analyses. Blood samples were collected for glucose-6-phosphate dehydrogenase (G6PD), glutathione peroxidase (GSH-Px) activity and trolox equivalent antioxidant capacity (TEAC) determination. Heart and liver tissues were used to quantify the expression of heat shock proteins 60 and 70 (HSP60 and HSP70, respectively) and inhibitor of kappa light chain gene enhancer in B cells alpha (IKBA). The jejunum was the most sensitive intestinal section, where heat stress modulated the expression of HSP70, of the inflammatory markers IKBA, interleukin 8 (IL-8), interferon gamma (IFNγ), and toll-like receptor 4 (TLR4). Moreover, expression of tight junctions (CLDN1, ZO1 and ZO2) and nutrient transporters (PEPT1 and EAAT3) was modulated especially in the jejunum. In conclusion, the feed additive blend protected intestines during heat stress from the decrease in villus height and crypt depth, and from the increase in villus width. Especially in the jejunum, heat stress played an important role by modulating oxidative stress and inflammation, impairing gut integrity and nutrient transport, and such deleterious effects were alleviated by the feed additive blend. RESEARCH HIGHLIGHTS Jejunum is the most sensitive intestinal segment during heat stress. Heat stress affects the expression of tight junctions and nutrient transporters. Feed management helps to alleviate the disturbances caused by heat stress. A blend of MCFA, organic acids and a polyphenol protects broilers under heat stress.

New perspectives to the enterotoxigenic E. coli F4 porcine infection model: Susceptibility genotypes in relation to performance, diarrhoea and bacterial shedding.

Enterotoxigenic E. coli (ETEC), causing post-weaning diarrhoea, is a major problem in weaned piglets. Individual animal responses to ETEC infection show high variability in animal experiments. Two studies were designed to optimize the ETEC F4ac infection model in piglets by combining the genotype susceptibility with performance, diarrhoea incidence and bacterial shedding. The studies were performed with respectively 120 and 80 male piglets that were tested for susceptibility or resistance towards ETEC O149:F4ac by a DNA marker based test. Three different genotypes were observed; resistant (RR), susceptible heterozygote (RS) and susceptible homozygote (SS). Piglets, were orally infected with an inoculum suspension (containing 1.5E8 CFU/ml ETEC F4ac) at day 0, 1 and 2 of the study. Performance, diarrhoea incidence and bacterial shedding were followed for 21days. In the first week after challenge a difference in average daily gain was observed between resistant and susceptible piglets in both studies. For the complete study period no significant differences were observed. Diarrhoea incidence was significantly higher in susceptible pigs compared to the resistant pigs in the first week after challenge. Bacterial shedding was much higher in the susceptible pigs and ETEC excretion lasted longer. ETEC was hardly detected in the faecal material of the resistant pigs. In conclusion, susceptible pigs showed higher diarrhoea incidence and higher numbers of faecal ETEC shedding in the first week after challenge compared to resistant pigs. The DNA marker based test can be used to select pigs that are susceptible for ETEC for inclusion in ETEC infection model, resulting in less animals needed to perform infection studies.

Quantitative histo-morphometric analysis of heat-stress-related damage in the small intestines of broiler chickens.

The aim of the current research was to present a methodological approach allowing reproducible morphometric and morphological (Chiu/Park scale) analyses of the alterations in the intestines of broilers exposed to heat stress. Ross broilers were exposed over four consecutive days to a high-temperature regime in controlled climate rooms, with a day temperature of 39°C (±1°C) and a night temperature of 25°C (±1°C), respectively. A control group was kept at an ambient temperature of 25°C (±1°C) during the entire experimental period. At the end of the exposure period, the birds were sacrificed and specimens were taken of the duodenum, jejunum and ileum for histology. Blood was collected for oxidative stress analysis. Histo-morphological and morphometric analyses of the intestines indicated that the duodenum and jejunum showed more damage than the ileum. The major alterations in the control intestines were limited to the villus tips, while heat stress led to villus denudation and crypt damage. When compared with morphologically normal villi, heat-stress-associated alterations were also observed in villus height (decreased), villus breadth at base (increased) and epithelial cell area (decreased). Birds exposed to heat stress presented with an increase in glutathione peroxidase activity and a decreased antioxidant capacity. It can be concluded that the chosen model allows a reproducible quantification of heat stress effects, which is suitable for the evaluation of dietary intervention strategies to combat heat stress conditions.

Bioactivity of tempe by inhibiting adhesion of ETEC to intestinal cells, as influenced by fermentation substrates and starter pure cultures.

Soya bean tempe is known for its bioactivity in reducing the severity of diarrhoea in piglets. This bioactivity is caused by an inhibition of the adhesion of enterotoxigenic Escherichia coli (ETEC) to intestinal cells. In this paper, we assessed the bioactive effect of soya tempe on a range of ETEC target strains, as well as the effect of a range of cereal and leguminous substrates and starter pure cultures. Soya bean tempe extracts strongly inhibited the adhesion of ETEC strains tested. All tempe made from other leguminous seeds were as bioactive as soya bean tempe, whereas tempe made from cereals showed no bioactivity. Using soya beans as substrate, fermentation with several fungi (Mucor, Rhizopus spp. and yeasts) as well as Bacillus spp. resulted in bioactive tempe, whereas fermentation with lactobacilli showed no bioactivity. The active component is released or formed during the fermentation and is not present in microbial biomass and only partly in unfermented substrates. The bioactivity being not specific for a single ETEC strain, makes the bioactive tempe relevant for applications in animal husbandry.

First characterization of bioactive components in soybean tempe that protect human and animal intestinal cells against enterotoxigenic Escherichia coli (ETEC) infection.

Tempe extracts can inhibit the adhesion of enterotoxigenic Escherichia coli (ETEC) to intestinal cells and thereby can play a role in controlling ETEC-induced diarrhea. The component responsible for this adhesion inhibition activity is still unknown. This research describes the purification and partial characterization of this bioactive component of tempe. After heating, defatting, and protease treatment, the extracts were found to remain active. However, after treatment with polysaccharide-degrading enzyme mixtures the bioactivity was lost. Ultrafiltration revealed the active component to be >30 kDa. Further purification of the bioactive tempe extracts yielded an active fraction with an increased carbohydrate content of higher arabinose content than the nonactive fractions. In conclusion, the bioactive component contains arabinose and originates from the arabinan or arabinogalactan side chain of the pectic cell wall polysaccharides of the soybeans, which is probably released or formed during fermentation by enzymatic modifications.

Role of germinant receptors in Caco-2 cell-initiated germination of Bacillus cereus ATCC 14579 endospores.

Spores obtained from Bacillus cereus ATCC 14579 and mutant strains lacking each of seven germinant receptor operons were exposed to differentiated Caco-2 cells and monitored for germination. Spores of the gerI and gerL mutants showed a reduced germination response, pointing to a role for these receptors in Caco-2-induced germination.