Effects of Akkermansia Muciniphila and Berberine Supplementation on Insulin Sensitivity in Night-shift Workers

Inclusion Criteria: * Health care or industrial shift worker * Employed or self-employed working ≥ 24 h/week * Current night shift work (night shift defined as a work schedule that includes at least 3 hours of work between 00:00 and 5:00) with at least 2 consecutive nights/month * Night shift work duration \> 3 years * 4 or more night shifts/month Exclusion Criteria: * BMI of 40 kg/m² or higher * Pregnancy or planned pregnancy within 6 months of enrolment or breastfeeding women * Bariatric surgery * Surgery in the 3 months prior to the study or planned surgery in the next 6 months that, in the opinion of the investigators, could potentially affect the outcome of the study * Diagnosed diabetes type 1 or type 2 * Uncontrolled thyroid disease (confirmed by clinically significant abnormal TSH/T4 levels without stable medication for more than 3 months) * Chronic diseases (renal failure, active hepatitis, liver cirrhosis, myocardial infarction within the last 2 years, stroke, chronic obstructive pulmonary disease or cancer) * Immunodeficiency syndrome, active autoimmune or autoinflammatory disease (e.g. multiple sclerosis, lupus, rheumatoid arthritis), inflammatory bowel disease (e.g. IBS or ulcerative colitis) and acute episodes of atopic diseases (atopic dermatitis, asthma, type 1 allergies such as hay fever). Grave's disease, Hashimoto thyroiditis, Celiac disease, sarcoidosis, Lichen planus, are allowed, if well treated and stable * Regular intake of anticoagulants * Known allergy to any inactive or active ingredients in the study products * Participation in other clinical intervention trials during the study * Current or planned participation in a weight loss program (including intermittent fasting), extreme diet, or vigorous exercise (e.g., running, fast cycling, swimming laps, or playing intense sports that quickly raise your heart rate)