Abstract: A method for producing bacteria belonging to the genus Bifidobacterium having excellent viability even under various conditions with different environmental factors, novel bacteria belonging to the genus Bifidobacterium obtained by the method, and a method for detecting the bacteria are provided. By subculturing and storing bacteria belonging to the genus Bifidobacterium alternately in systems under conditions with different environmental factors, the bacteria belonging to the genus Bifidobacterium exhibiting excellent viability under all the conditions used for the alternate subculturing and storing can be produced.

Abstract: A method for producing bacteria belonging to the genus Bifidobacterium having excellent viability even under various conditions with different environmental factors, novel bacteria belonging to the genus Bifidobacterium obtained by the method, and a method for detecting the bacteria are provided. By subculturing and storing bacteria belonging to the genus Bifidobacterium alternately in systems under conditions with different environmental factors, the bacteria belonging to the genus Bifidobacterium exhibiting excellent viability under all the conditions used for the alternate subculturing and storing can be produced.

Abstract: A bone metabolism improving agent characterized by containing as the active ingredient fermented soybean milk which is obtained by fermenting soybean milk with a lactic acid bacterium or a bifidobacterium. The bone metabolism improving agent is efficacious in treating and preventing diseases in association with lowered bone metabolism such as osteoporosis and, at the same time, satisfies requirements in cost and smooth intake.

Abstract: A Bifidobacterium that is resistant to acid and bile and which retains at least 20% viability after acid and bile treatment. Foods and drinks containing an acid- and bile-resistant Bifidobacterium. Methods for providing viable Bifidobacteria to the intestine after ingestion of a food or drink containing an acid- and bile-resistant Bifidobacterium.

Abstract: A bone metabolism improving agent characterized by containing as the active ingredient fermented soybean milk which is obtained by fermenting soybean milk with a lactic acid bacterium or a bifidobacterium. The bone metabolism improving agent is efficacious in treating and preventing diseases in association with lowered bone metabolism such as osteoporosis and, at the same time, satisfies requirements in cost and smooth intake.

Abstract: Provided is a method of assessing the extent to which Bifidobacterium bacteria in a Bifidobacterium-bacteria-containing fermented milk food or drink reach the intestines when the food or drink is orally administered to human beings, which comprises subjecting the fermented milk food or drink to successive treatments with an acid and bile, and measuring the bacterial viability after the treatments.

Abstract: A bone metabolism improving agent characterized by containing as the active ingredient fermented soybean milk which is obtained by fermenting soybean milk with a lactic acid bacterium or a bifidobacterium.

Abstract: A Bifidobacterium breve strain provided is showing a viable count of 1×109 cells/ml or more immediately after culturing in a soymilk medium and sustaining a viable count of 1×108 cells/ml or more after storage at 10° C. for 14 days. The strain is preferably Bifidobacterium breve FERM BP-6223, and is used for producing fermented soymilk.