A clinical study for evaluating the effects of lactic acid bacterium containing foods on improvement of bowel movement and immune function. : randomized, double-blind, placebo-controlled parallel trial

INTERVENTION: Pre‐treatment observation period(1 week), treatment observation period, subject take the test food(4 weeks), post‐treatment observation period(2 weeks) Pre‐treatment observation period(1 week), treatment observation period, subject take the placebo food(4 weeks), post‐treatment observation period(2 weeks) CONDITION: Healthy adult PRIMARY OUTCOME: Defecation frequency, feeling after defecation, ease of defecation, amount, smell and color of feces, fecal condition (Measure at a daily basis for 1 week during the pre‐treatment period, and in the week right before the 2nd, 4th and 6th week when the treatment started); Activity of NK cell and concentration of IgA in blood; (Measure at before ingestion and after 4‐week intake) SECONDARY OUTCOME: Adverse event(Inquiry consultation) ; Blood lipid maker; (Measure at before ingestion and after 4‐week intake) INCLUSION CRITERIA: