An Integrative Study of the Role of Microbiome, Metabolome, Transcriptome and Chronobiology in the Context of Type 2 Diabetes.

Prior treatment

• Self-reported use of drugs of abuse in the last 12 months.
• Recent travel across 2 or more time zones during the last month before the start of the study.
• Blood donation in the 3 months prior to the beginning of the study.
  • Medical conditions:
• Subjects who have undergone surgery of the digestive tract with permanent sequelae, including surgical treatment for obesity.
• Current or within the previous 2 months use of prescription or non-prescription medication or nutritional supplements that have the potential to affect glycaemic control, as well as biochemical analyses. For food supplements containing biotin, they are permitted provided that their consumption is omitted 48 h before blood draws.
• Current or within the previous 2 months use of nutritional supplements or prescription or non-prescription drugs that may affect the microbiota (probiotics, prebiotics, fibre, antibiotics, antifungals).
• Taking any medication that may seriously affect circadian rhythms (melatonin receptor agonist drugs (tasimelteon, ramelteon), drugs for the treatment of drowsiness (modafinil, armodafinil), or with sedative effects (benzodiazepines, zolpidem)) or nutritional supplements that contain melatonin and are likely to affect circadian rhythms, except if on a stable dose for 3 months or more.
• Cholesterol-lowering medication, except if on a stable dose for 3 months or more.
• Blood pressure lowering medication, unless on a stable dose for 3 months or more.
• Medication that may affect appetite and body weight (e.g. antidepressants, thyroid) unless on a stable dose for 3 months or more and without significant side effects.

Other illness

• Oral diseases, inflammation or lesions at the time of the study.
• Any clinical condition, including chronic metabolic diseases, systemic intestinal, hepatic or renal diseases, when the research team consider that it may influence the results of the study.
• Severe hyperlipidaemia, severe hypertension or hypothyroidism, untreated or treated for less than 3 months with stable dose.
• Have relevant functional or structural abnormalities of the digestive tract, such as malformations, angiodysplasias, active peptic ulcers, chronic inflammatory diseases or malabsorption.
• Any type of psychological/psychiatric impairment such as depressive pathology, anxiety or bipolar disorder, when the research team consider that it may influence the results of the study.
• Any type of cancer or be undergoing treatment for it, or that a period of at least 5 years has not elapsed since its eradication.
• A diagnosed eating disorder (such as bulimia or binge eating disorder)
• Any infection at the time of the study, especially respiratory or intestinal infection.
  • Medication:

Other

• Chronotype within the categories "extreme evening" (\<34) or "extreme morning" (\>76), according to the Hörne-Orberg Morning-Evening Questionnaire (MEQ) classification.
• Weight changes (± 4.5 kg) during the last 3 months.
• Habitually consuming ≥ 14 units of alcohol/week in women and ≥ 21 units of alcohol/week in men.
• Be an active smoker or have quit smoking within the last 3 months.
• Night or late shift work (finishing later than 11 pm on a permanent basis).
• Show poor cooperation or, in the opinion of the investigator, have difficulty following the study procedures.
• In the case of women, being pregnant or breastfeeding .
• Presence of any type of health problem that may affect sleep
• Be under continuous pharmacological/hormonal treatment that may affect glycaemic control.

• Women and men between the ages of 30 and 70.
• Meet any criteria diagnosis of prediabetes or type 2 diabetes according to the American Diabetes Association (ADA), without pharmacological treatment for glycaemic control.
• Excess weight, according to body mass index (BMI) value \> 25 kg/m2.
• Body fat percentage, measured by bioelectrical impedance analysis (BIA), above the normal range, according to age and sex, following the classification from Gallagher D, et al. Am J Clin Nutr. 2000;72(3):694-701.
• Women and men between the ages of 30 and 70.
• No impaired glucose metabolism according to ADA diagnostic criteria
• Normal weight, according to BMI value (18,5 - 24,9 kg/m2)
• Body fat percentage, measured by BIA, within the normal range, according to age and sex, following the classification from Gallagher D, et al. Am J Clin Nutr. 2000;72(3):694-701.