Inclusion Criteria:  Volunteer is healthy at the time of pre-examination Possess mild/moderately elevated levels of stress Volunteer is aged ≥ 18 to ≤ 45 years at the time of pre-examination Volunteer's BMI is ≥ 18.5 and ≤ 29.9 Volunteer has a stool frequency of at least 3 bowel movements per week Volunteer is able and willing to comply with the study instructions Volunteer is suitable for participation in the study according to the investigator/study personnel Written informed consent is given by volunteer  Exclusion Criteria:  No command of any local language Previously or currently diagnosed neurological or psychiatric disorders Previous history of renal, hepatic, cardiovascular disease or clinically significant diabetes Gastrointestinal disorders including IBS, IBD or other conditions that might affect the gut environment Food allergies or intolerances Using drugs (e.g. antibiotics, aspirin, proton pump inhibitors) influencing gastrointestinal function (8 weeks before intervention) Use of laxatives and labelled pre-and probiotics in the previous 4 weeks before the beginning of intervention Volunteers currently involved or will be involved in another clinical or food study History of drug (recreational) or alcohol abuse. Use of anti-depressants medication including selective serotonin receptor inhibitors or Amitriptyline for 3 months prior to commencing the trial Received bowel preparation for investigative procedures in the 4 weeks prior to the study Undergone surgical resection of any part of the bowel. pregnant or lactating