Presence of Butyrivibrio fibrisolvens in the digestive tract of dogs and cats, and its contribution to butyrate production

Numbers of Butyrivibrio fibrisolvens, a major butyrate-producing bacterium in the rumen, in feces of dogs and cats were estimated by competitive PCR. The type IIb of B. fibrisolvens, which produces much more lactate than butyrate, was detected at the levels (cells per g of feces dry weight) of 2.4x10(3)-9.0x10(5) for dogs and 1.7x10(4)-6.2x10(5) for cats. However, the type I that produces much more butyrate than the type IIb was not detected in cat or dog feces (less than 6.0x10(4) cells per g of feces dry weight). Butyrate production by B. fibrisolvens type IIb in feces was estimated to be at most 30% of the butyrate production by mixed fecal microbes, which suggested that more butyrate is produced by microbes other than B. fibrisolvens in the intestines. Addition of B. fibrisolvens ATCC19171 (type I) to a culture of mixed fecal microbes increased butyrate production, and OB156 (type IIb) increased lactate production. When both the types were added, both the products were increased. Thus, introduction of both the types of B. fibrisolvens as a probiotic may increase butyrate and lactate production in the large intestine, which is possibly beneficial for the maintenance or improvement of the health of dogs and cats.