Effect of fructooligosaccharide on Salmonella colonization of the chicken intestine.

The influence of fructooligosaccharide (FOS) on the ability of Salmonella typhimurium to grow and colonize the gut of chickens was investigated. In vitro studies showed that Salmonella did not grow when FOS was the sole carbon source. When FOS was fed to chicks at the .375% level, little influence on Salmonella colonization was observed. At the .75% level, 12% fewer FOS-fed birds were colonized with Salmonella compared with control birds. When chicks given a partially protective competitive exclusion (CE) culture were fed diets supplemented with .75% FOS, only 4 of 21 (19%) chickens challenged with 10(9) Salmonella cells on Day 7 became colonized as compared with 14 of 23 (61%) chickens given CE alone. When chickens were stressed by feed and water deprivation on Day 13 and challenged with 10(9) Salmonella on Day 14, 33 of 36 (92%) chickens fed a control diet were colonized compared with only 9 of 36 (25%) chickens fed a .75% FOS diet. Chickens treated with FOS had a fourfold reduction in the level of Salmonella present in the ceca. Feeding FOS in the diet of chickens may lead to a shift in the intestinal gut microflora, and under some circumstances may result in reduced susceptibility to Salmonella colonization.