IN-VIVO COLONIC ELECTROLYTE FLUX IN DOGS FED SOYPROTEIN, CASEIN OR MEAT AS THEIR PRIMARY-PROTEIN SOURCE

Fifteen adult, mongrel dogs were used in a study to assess the effects of dietary protein on canine colonic electrolyte transport. The dieta ry protein sources used in the study were soyprotein, casein and meat (i.e., freeze-dried beef muscle). The experiment was a completely rand om allocation of treatments, with dogs as the experimental unit. Each animal was adapted to their respective diet for a minimum of 14 days p rior to beginning the laboratory phase of the study. The colon of each animal was then cleansed and perfused with a known test solution to a ssess the apparent absorption/secretion of sodium, chloride and short chain fatty acids (SCFA) in the intact animal. The net flux of total a nd individual SCFA was affected by dietary treatment. Soyprotein fed d ogs bad greater total SCFA and individual SCFA (acetate, propionate an d butyrate) absorption than did the meat fed animals. Transport of tot al and individual SCFA for the casein fed dogs was generally between t hat of the soyprotein and meat fed animals. Casein fed dogs absorbed s ignificantly more acetate and propionate than the meat fed, and signif icantly less propionate and butyrate than the soyprotein fed animals. Sodium and chloride transport was not affected by protein source.