Abstract: A milk raw material is fermented by using Lactococcus lactis not having cell wall-enveloped proteinase and a Bifidobacterium bacterium. The Lactococcus lactis is, for example, a Lactococcus lactis having a property that, when this bacterium and the Bifidobacterium bacterium are inoculated into a medium containing 1% (W/W) of glucose and 10% (W/W) of reduced skim milk powder in amounts of 5.0×106 to 2.0×108 CFU and 1.0×107 to 3.0×109 CFU per 1 ml of the medium, respectively, and cultured, and the medium is rapidly cooled to 10° C. from culture temperature when pH of the medium becomes 4.6 to 5.5, and stored at 10° C. for 2 weeks, survival rate of the Bafidobacterium bacterium is maintained to be 30% or more.

Abstract: An object is to provide an interleukin production regulator which can be used for prevention, treatment or recurrence prevention of a gastrointestinal disease or an autoimmune disease accompanied by an inflammation as the main symptom, which is highly safe, and which can be administered over a long period. Another object is to provide a method for production of the interleukin production regulator. Further object is to provide a pharmaceutical composition and a food, each of which comprises the interleukin production regulator. Disclosed are: a method for producing an interleukin production regulator having both an effect of maintaining or promoting the production of interleukin-10 and an effect of maintaining or inhibiting the production of interleukin-12, comprising the step of disrupting a cell of a microorganism belonging to the genus Bifidobacterium; an interleukin production regulator produced by the method; and a pharmaceutical and a food, each comprising the interleukin production regulator.

Abstract: 17It is intended to provide Bifidobacterium longum having the following bacteriological properties and microbial powders, foods and beverages containing this Bifidobacterium longum: (1) having such fermentation ability as to make a milk base medium to pH 4.6 or below; (2) showing a survival rate of 50% or more in the case of, after attaining pH 4.4 to 4.6 in a milk base medium, quenching and storing at 10° C. for two weeks; and (3) having such gastric juice tolerance as to yield a survival rate of 10% or more in the case of storing in artificial gastric juice (pH 3.0) at 37° C. for two hours.

Abstract: 17It is intended to provide Bifidobacterium longum having the following bacteriological properties and microbial powders, foods and beverages containing this Bifidobacterium longum: (1) having such fermentation ability as to make a milk base medium to pH 4.6 or below; (2) showing a survival rate of 50% or more in the case of, after attaining pH 4.4 to 4.6 in a milk base medium, quenching and storing at 10° C. for two weeks; and (3) having such gastric juice tolerance as to yield a survival rate of 10% or more in the case of storing in artificial gastric juice (pH 3.0) at 37° C. for two hours.