The objective of this study is to evaluate if consumption of fermented milk containing Lactobacillus casei strain Shirota has an impact on stool consistency, stool frequency, constipation-related symptoms, and quality of life in subjects who frequently have hard or lumpy stools.

Constipation is a common problem affecting approximately 17% of the general population in Europe. Several reports suggest that production of hard or lumpy stools (HLS) is strongly associated with the development of constipation. HLS are produced not only by chronic constipated patient but also by healthy population. Thus, reducing the incidence of HLS might be beneficial in terms of reducing the incidence of constipation in healthy population.

The results of two clinical studies conducted in Europe indicate the positive effect of fermented milk (FM) containing Lactobacillus casei strain Shirota (LcS) to modulate the hardness or dryness of stools. Koebnick et al. (2003) reported that consumption of the FM drink containing LcS decreased the occurrence of hard or lumpy stools, and improved the severity of constipation in patients with chronic constipation in Germany. An open trial conducted in Ghent, Belgium used commercially available FM containing LcS (Yakult® Light) in subjects who frequently had hard or lumpy stools, screened by an average Bristol Stool Form Scale (BS) score < 3.0. After 3 weeks of treatment, the proportion of subjects who produced hard or lumpy stools (BS score = 1 or 2) ≥ 25% of bowel movements decreased from 73.7% at baseline to 36.8%, while in the non-intervention control group the proportion increased from 75.0% to 85.0% during the same period. Based on the results of those studies, it was anticipated that LcS might assist in reducing the production of hard or lumpy stools in the general population. In order to confirm the efficacy in healthy population, a randomised, double blind, placebo control study is required.

Inclusion Criteria; a subject:

• is informed both verbally and in writing about the objectives of the clinical study, the methods, the anticipated benefits and potential risks and the discomfort to which he/she may be exposed, and give written consent to participate in the study prior to the start of any study-related procedures
• is healthy female or male, 18-65 years of age, inclusive
• is conscious of having hard or lumpy stools in daily life
• has an average Bristol Stool Form Scale score <3.0 per bowel movement
• female subjects of childbearing potential should use a reliable method of contraception

Exclusion Criteria; a subject:

• is under the age of legal consent
• is mentally or legally incapacitated
• is treated by a doctor for her/his constipation
• has a history of gastrointestinal surgery except for appendectomy
• has a history of chronic gastrointestinal diseases, including but not limited to inflammatory bowel diseases
• has a severe gastrointestinal disorder
• has clinically relevant medical conditions, e.g., renal, hepatic, pulmonary, cardiac, hematological, endocrinological, neurological, or psychiatric conditions
• is pregnant or wanting to become pregnant during the course of the study
• is unable to refrain from or anticipates the use of any medication (including laxatives, diuretics, prescription and non-prescription drugs, vitamins and herbal supplements), except for paracetamol, oral contraceptives, or hormonal replacement therapy during the screening visit and for the duration of the study
• has a history of drug and/or alcohol abuse
• has milk allergies
• is intolerant to lactose