Inclusion Criteria:  Working 3x8 shifts (weekly rotations between AM, PM and N shifts) for at least 3 months prior to the study No anticipated changes in shift work planning No prebiotics or probiotics supplements.  Exclusion Criteria:  Antibiotic and/or immunomodulator use in the last 3 months or during the study Change in medication during the last month or during study Inflammatory bowel disease or important gut surgery Nuts allergy Major digestive tract surgery.