1- Which scientific committee reviewed the protocol?

2-Funding amount is in what currency?

3- Employees  may be considered a vulnerable group, vulnerable to coercion. Please explain how the investigator will avoid coercion in the population of employees.

4- Study population: please justify the use of this population.

5- Criteria for discontinuation should mention that participants could be withdrawn if they do no want to continue participation.

6-Methodology: The methodology is not clear.

a-What are the 4 bacteria that will be tested?

b-Why culture the stool, while PCR  could be done directly on the stool?

c-The chart does not mention stool collection.

d-The chart mentions 2 groups according to diet and depression, then 4 groups according to depression. Please explain how many groups will be available at the end?

e- What are the criteria for the nutritional groups?

f-We need to review the questionnaires used in the study

g- The co-investigators do not include a psychologist or psychiatrist for the review depression part.

h-Who decided about the depression questionnaire to be used?

i- What is the statistical analysis plan?

7- Statistics: Was the number of groups included in the sample size calculation?

8- What are the benefits of the study? These should be mentioned.

9-Informed Consent:

a- Needs revision of the Arabic language. For example: قد تم تعاني

and others

b- The consent mentions that the participants may have depression, on which basis? The protocol mentions normal employees!

c- Consent mentions 4 groups according to nutrition, while the chart mentions 4 groups according to depression status.