The Ussing chamber technique to evaluate alternatives to in-feed antibiotics for young pigs

Abstract

The recent ban of in-feed antibiotics in animal production has brought scientists to find alternatives to in-feed antibiotics. The Ussing chamber is an in vitro technique in which intestinal tissue is collected and immediately mounted as a flat sheet between two half-chambers, establishing a luminal and a serosal side. This technique allows the measurement of actively transported ions as well as the permeability of the tissues, two parameters relevant for the evaluation of gut health. Ussing chambers have been used to describe the changes of intestinal physiology occurring at weaning. We observed that weaning induces an acute alteration of the epithelial barrier function and electrolyte transport in the first days. Long-lasting modifications (15 days after weaning) have also been observed. Alternatives to in-feed antibiotics can be evaluated by studying the intestinal physiology of animals treated with those alternatives. A benefic effect of pro- and pre-biotics on the rat intestine, human biopsies or epithelial cell monolayers has been demonstrated using Ussing chambers. In pigs, the influence of the source of dietary ingredients or the physical form of the diet seems limited. A few results obtained in pigs with pre- or probiotics appear less convincing than in laboratory animals. Another way to use Ussing chambers is to incubate the intestinal tissue with different substances added directly into the chambers. Some substances can be detrimental to the intestine, inducing electrolyte secretion or decreasing barrier function. However, some substances show a beneficial effect. Although this approach has limits and should be combined with in vivo measurements, it constitutes a rapid way to evaluate the effect of substances on intestinal physiology and can also, at least partly, elucidate the mechanisms of action of those alternatives. © INRA, EDP Sciences, 2005.