This study will investigate whether changes in the gut microbiota generated after the consumption of a high protein diet in healthy subjects, modify the production of secondary bile acids. In addition, it will be seen whether a high protein intake modifies postprandial glucose response and its relationship with gut microbiota composition.

The gut microbiota is a set of microorganisms that inhabit the human digestive tract and are fundamental for the health of the host. Among the functions of the gut microbiota is the production of metabolites, such as the production of secondary bile acids from primary bile acids. On the other hand, evidence has shown that the amount of protein intake can modify the composition of the gut microbiota and in turn it increase the concentration of secondary biles acids in animal models. In addition, the consumption of a high-protein diet has been related to a decrease in postprandial glucose concentrations. Therefore, the aim of this study is to evaluate changes in secondary bile acids concentration derived from gut microbiota after the consumption of a high-protein diet in healthy subjects. Subjects with a BMI between 18.5 and 24.9 kg/m2 will be selected and will be continuously monitored with a continuous glucose monitor through 15 days. During the first 7 days participants will follow an isocaloric diet (50% carbohydrates, 30% fat and 20% protein), while during the last 7 days participants will receive an intervention with a supplement of protein (calcium caseinate) which will increase their protein intake to 30% of the total energy requirement. At the initial and final visit, blood samples will be taken for determination of biochemical parameters, amino acids and primary bile acids and a stool sample will be requested for sequencing gut microbiota and determined secondary bile acids.

Inclusion Criteria:

• Male and female.
• Between 18 and older
• BMI ≥ 18.5 and ≤ 24.9 kg/m2.
• Healthy
• Willing and able to sign written informed consent prior to trial entry

Exclusion Criteria:

• Have previously diagnosed with any chronic disease

• Patients with high blood pressure.

• Patients who have suffered a cardiovascular event.

• Patients with gastrointestinal diseases.

• Weight loss > 3 kg in the last 3 months.

• Catabolic diseases such as cancer and acquired immunodeficiency syndrome.

• Pregnancy status.

• Antibiotic consumption 3 months prior to the study.

• Be an undergraduate or graduate student within the Institute.

• Subjects with creatinine > 1.3 mg/dL for men and >1 mg/dL for women and ureic nitrogen > 20 mg/dL.

• Positive smoking.

• Drug treatment:

  1. Antihypertensive drugs or treatment
  2. Treatment with hypoglycemic agents or insulin and antidiabetic drugs.
  3. Treatment with statins, fibrates or other drugs to control dyslipidemia.
  4. Use of antibiotics in the three months prior to the study.
  5. Use of steroid drugs, chemotherapy, immunosuppressants, or radiation therapy.
  6. Anorexigenic or that accelerate weight loss such as sibutramine or orlistat.
  7. Probiotic, prebiotic or symbiotic supplements.