Table 2. The total number of articles based on the inclusion and exclusion criteria.

MeSH: Medical Subject Heading

MeSH Keywords:
Gastrointestinal Microbiome (Subheading- Etiology)
Total Records	2984
Human Population	2047
English Literature	2938
Records Selected	2005
Gastrointestinal Microbiome (Subheading- Physiology)
Total Records	5532
Human Population	3889
English Literature	5405
Records Selected	3772
Depression (Subheading- Anatomy, and Histology)
Total Records	1608
Human Population	1138
English Literature	1530
Records Selected	1072
Depression (Subheading- Etiology)
Total Records	34581
Human Population	32220
English Literature	31113
Records Selected	28883
Depression (Subheading- Psychology)
Total Records	36971
Human Population	35823
English Literature	35088
Records Selected	33984
Gastrointestinal Microbiome (Subheading- Etiology, and Physiology) and Depression (Subheading- Anatomy and Histology, Etiology, and Psychology)
Total Records	44
Human Population	28
English Literature	43
Records Selected	27