Butyrate-producing bacteria in the intestines of dogs

Abstract

In order to know what bacteria contribute to butyrate production in the intestinal tract of dogs, butyrate-producing bacteria were isolated from the feces. Of the 720 bacteria isolated,88 isolates produced significant amounts of butyrate (more than 10% of butyrate in the total fermentation products). Numbers of butyrate-producing bacteria, as well as the bacteria having high ability to produce butyrate, decreased with the ages of dogs, suggesting that butyrate production decreases with the age. As butyrate-producing bacteria, Eubacterium sp., Fusobacterium sp., Clostridium sp., and Butyrivibrio sp. were identified. The Butyrivibrio sp. isolated was identified as Butyrivibrio fibrisolvens. Among these butyrate-producing bacteria, the number of Eubacterium sp. was the largest. An isolate that resembled Eubacterium rectale produced a high percentage (>50%) of butyrate. Numbers of Eubacterium sp., Fusobacterium sp., and Butyrivibrio sp. also decreased with the ages of dogs, whereas the number of Clostridium sp. did not change with the age. Therefore, in senior dogs, Clostridium appears to be a predominant butyrate-producing microorganism. Since Clostridium is thought to have unfavorable effects on the host animal, it is desirable to increase the numbers of Eubacterium sp. and Butyrivibrio sp. in senior dogs, not only to increase butyrate production but also to suppress Clostridium.