Jean Paul Lalles

Diet-related adaptation of the small intestine at weaning in pigs is functional rather than structural.

Background Incidence of diarrhea at weaning in commercial pigs is an important problem, and diet is thought to be a predisposing factor. The aim of this study was to determine the impact of switching from milk-based to cereal-based diets on the morphology and function of the small intestine of piglets using a model of delayed weaning to isolate the influence of the diet from that of environmental and social factors. Methods Forty-five piglets received a milk-based diet for 5 weeks after weaning. Thirty piglets were then switched from milk-based to wheat- or barley-based diets, mimicking the dietary change that occurs at weaning. The last 15 piglets remained on the milk-based diet. Piglets were killed 4 days after the dietary switch. Jejunal mucosa morphometry and enzyme activities were measured. Ussing chambers were used to measure intestinal permeability to macromolecules, basal electrical properties, glucose absorption, and induced chloride-secretion. Results Alkaline phosphatase– and sucrase-specific activities were higher in both groups of cereal-fed piglets than in milk-fed piglets. Dipeptidylpeptidase IV activity was higher in wheat-fed piglets than in the other groups. Na+-dependent glucose absorption was 1.7-fold higher in cereals-fed piglets than in milk-fed piglets. Serotonin-induced and vasoactive intestinal polypeptide–induced chloride secretion was doubled in cereals-fed piglets. Dietary transition did not influence the other parameters. Conclusions These results indicate that switching from milk to cereals increased some mucosal enzyme activities, intestinal Na+–dependent glucose absorption, and response to secretagogues. This supports the hypothesis that dietary factors could initiate diarrhea in the presence of other aggravating factors, such as pathogens or environmental stress.

Case studies on genetically modified organisms (GMOs): Potential risk scenarios and associated health indicators

Within the frame of the EU-funded MARLON project, background data were reviewed to explore the possibility of measuring health indicators during post-market monitoring for potential effects of feeds, particularly genetically modified (GM) feeds, on livestock animal health, if applicable. Four case studies (CSs) of potential health effects on livestock were framed and the current knowledge of a possible effect of GM feed was reviewed. Concerning allergenicity (CS-1), there are no case-reports of allergic reactions or immunotoxic effects resulting from GM feed consumption as compared with non-GM feed. The likelihood of horizontal gene transfer (HGT; CS-2) of GMO-related DNA to different species is not different from that for other DNA and is unlikely to raise health concerns. Concerning mycotoxins (CS-3), insect-resistant GM maize may reduce fumonisins contamination as a health benefit, yet other Fusarium toxins and aflatoxins show inconclusive results. For nutritionally altered crops (CS-4), the genetic modifications applied lead to compositional changes which require special considerations of their nutritional impacts. No health indicators were thus identified except for possible beneficial impacts of reduced mycotoxins and nutritional enhancement. More generally, veterinary health data should ideally be linked with animal exposure information so as to be able to establish cause-effect relationships.

Fosfatasa alcalina intestinal: una enzima con propiedades antiinflamatorias

Resumen Una de las principales funciones de la Fosfatasa Alcalina Intestinal (FAI) es la detoxificacion de los lipopolisacaridos (LPS) bacterianos para controlar la inflamacion intestinal. Recientes publicaciones indican que FAI participa en la detoxificacion de otros compuestos bacterianos (flagelina y motivos CpG de DNA) y de muchos nucleotidos libres (ATP, UDP). FAI esta involucrada de manera directa en la recuperacion tisular de la inflamacion por la Resolvina E1. La accion antiinflamatoria de FAI mejora indirectamente la funcion de la barrera intestinal e impacta la diversidad y la composicion de la microbiota. Diversas enfermedades intestinales, incluyendo enterocolitis necrotica, enfermedad celiaca y la inflamacion cronica intestinal (o inflammatory bowel disease, IBD) estan relacionadas con disminuciones en la expresion y actividad de FAI. Por otro lado, una elevada actividad de FAI en colon es sinonimo de procesos inflamatorios, debido a la elevada concentracion de la isoforma tisular de Fosfatasa Alcalina no especifica (FANE), y a la infiltracion tisular por los neutrofilos (que tambien contienen FANE). En algunos ensayos en humanos se ha observado que la administracion exogena de FAI reduce la inflamacion intestinal/sistemica (dependiendo de la via de administracion). En conclusion, la homeostasis intestinal y la preservacion de la salud dependen en gran medida de la capacidad de FAI para detoxificar los LPS y suprimir la inflamacion metabolica inducida por estos. Sin embargo, es necesario realizar investigaciones a fondo sobre como los habitos alimenticios pueden modificar la detoxificacion de los diferentes compuestos proinflamatorios bacterianos y maximizar la actividad de FAI