Reviewer ’s report  
 
Title: Global research trends in microbiome -gut-brain axis during 2009 -2018: a bibliometric and 
visualized study  
 
Version: 0 Date: 21 Jun 2019  
Reviewer: Sofia Cussotto  
Reviewer's report:  
Manuscript No. BMGE -D-19-00412  
Here the authors analyse the trends on microbiome research over the last 10 years. The review is 
well written, and the authors address an aspect of particular relevance, as the microbiome -brain 
research is currently facing a period of "hype". I have no major concerns but I suggest some 
minor comments that the authors may consider in order to improve the manuscript.  
 
Page 3, line 3: please cite direct evidence of the statement instead of ref 1 -5  
Page 4, lines 5 and 10: Please cite primary research papers instead of reviews (ref 30 and 23)  
Page 4, line 10: when discussing bifidobacteria increasing resilience in humans, ther e are also 
other papers that show the difficulties of translating preclinical findings into humans (e.g. doi: 
10.1016/j.bbi.2016.11.018). I think it would be important to stress this point and cite some 
examples of human research where probiotics failed to  improve stress.  
Page 5, line 7: what does "has the largest one" mean? Is it referred to the quality standard? Not 
clear. Please rephrase  
Page 10, line 2: capital "A"  
Table 3: the separation across lines is not clear, I found it difficult to understand whi ch author 
was linked to which paper. If possible, make it more clear  
Figure 3: why Ireland, UK and Spain are listed in table 1 but are not found on this map? Spain 
could be missing because of the low number of publications, but Ireland and UK are amongst t he 
most productive countries according to table 1  
Legend of Figure 3 and 4: There is no indication of colour -codes. I suppose they are coloured 
according to the 4 sub -topics? It would be better to specify this in the figure legends.  
Figure 3: is there a s pecific reason why yellow and blue are not present in figure 3? If yes, please 
explain in figure legend  
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Unable to assess  
 
Are the conclusions drawn  adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would you recommend an 
additional statistical review?  
If an additional statistical review is r ecommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financia lly from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold o r are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do yo u have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the  above, write 'I declare that I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will  be included 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available unde r an Open Access Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ).  I understand that any comments 
which I do not wish to be included in my named report can be included  as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
Reviewer ’s report  
 
Title: Global research trends in microbiome -gut-brain axis during 2009 -2018: a bibliometric and 
visualized study  
 
Version: 0 Date: 21 Jun 2019  
Reviewer: Sofia Cussotto  
Reviewer's report:  
Manuscript No. BMGE -D-19-00412  
Here the authors analyse the trends on microbiome research over the last 10 years. The review is 
well written, and the authors address an aspect of particular relevance, as the microbiome -brain 
research is currently facing a period of "hype". I have no major concerns but I suggest some 
minor comments that the authors may consider in order to improve the manuscript.  
 
Page 3, line 3: please cite direct evidence of the statement instead of ref 1 -5  
Page 4, lines 5 and 10: Please cite primary research papers instead of reviews (ref 30 and 23)  
Page 4, line 10: when discussing bifidobacteria increasing resilience in humans, ther e are also 
other papers that show the difficulties of translating preclinical findings into humans (e.g. doi: 
10.1016/j.bbi.2016.11.018). I think it would be important to stress this point and cite some 
examples of human research where probiotics failed to  improve stress.  
Page 5, line 7: what does "has the largest one" mean? Is it referred to the quality standard? Not 
clear. Please rephrase  
Page 10, line 2: capital "A"  
Table 3: the separation across lines is not clear, I found it difficult to understand whi ch author 
was linked to which paper. If possible, make it more clear  
Figure 3: why Ireland, UK and Spain are listed in table 1 but are not found on this map? Spain 
could be missing because of the low number of publications, but Ireland and UK are amongst t he 
most productive countries according to table 1  
Legend of Figure 3 and 4: There is no indication of colour -codes. I suppose they are coloured 
according to the 4 sub -topics? It would be better to specify this in the figure legends.  
Figure 3: is there a s pecific reason why yellow and blue are not present in figure 3? If yes, please 
explain in figure legend  
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Unable to assess  
 
Are the conclusions drawn  adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would you recommend an 
additional statistical review?  
If an additional statistical review is r ecommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financia lly from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold o r are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do yo u have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the  above, write 'I declare that I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will  be included 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available unde r an Open Access Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ).  I understand that any comments 
which I do not wish to be included in my named report can be included  as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
Please review this paper.
user
Reviewer ’s report  
 
Title: Global research trends in microbiome -gut-brain axis during 2009 -2018: a bibliometric and 
visualized study  
 
Version: 0 Date: 21 Jun 2019  
Reviewer: Sofia Cussotto  
Reviewer's report:  
Manuscript No. BMGE -D-19-00412  
Here the authors analyse the trends on microbiome research over the last 10 years. The review is 
well written, and the authors address an aspect of particular relevance, as the microbiome -brain 
research is currently facing a period of "hype". I have no major concerns but I suggest some 
minor comments that the authors may consider in order to improve the manuscript.  
 
Page 3, line 3: please cite direct evidence of the statement instead of ref 1 -5  
Page 4, lines 5 and 10: Please cite primary research papers instead of reviews (ref 30 and 23)  
Page 4, line 10: when discussing bifidobacteria increasing resilience in humans, ther e are also 
other papers that show the difficulties of translating preclinical findings into humans (e.g. doi: 
10.1016/j.bbi.2016.11.018). I think it would be important to stress this point and cite some 
examples of human research where probiotics failed to  improve stress.  
Page 5, line 7: what does "has the largest one" mean? Is it referred to the quality standard? Not 
clear. Please rephrase  
Page 10, line 2: capital "A"  
Table 3: the separation across lines is not clear, I found it difficult to understand whi ch author 
was linked to which paper. If possible, make it more clear  
Figure 3: why Ireland, UK and Spain are listed in table 1 but are not found on this map? Spain 
could be missing because of the low number of publications, but Ireland and UK are amongst t he 
most productive countries according to table 1  
Legend of Figure 3 and 4: There is no indication of colour -codes. I suppose they are coloured 
according to the 4 sub -topics? It would be better to specify this in the figure legends.  
Figure 3: is there a s pecific reason why yellow and blue are not present in figure 3? If yes, please 
explain in figure legend  
Are the methods appropriate and well described?  
If not, please specify what is required in your comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Unable to assess  
 
Are the conclusions drawn  adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manuscript or would you recommend an 
additional statistical review?  
If an additional statistical review is r ecommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, considering the following questions:  
 
1. Have you in the past five years received reimbursements, fees, funding, or salary from an 
organisation that may in any way gain or lose financia lly from the publication of this 
manuscript, either now or in the future?  
 
2. Do you hold any stocks or shares in an organisation that may in any way gain or lose 
financially from the publication of this manuscript, either now or in the future?  
 
3. Do you hold o r are you currently applying for any patents relating to the content of the 
manuscript?  
 
4. Have you received reimbursements, fees, funding, or salary from an organization that 
holds or has applied for patents relating to the content of the manuscript?  
 
5. Do yo u have any other financial competing interests?  
 
6. Do you have any non -financial competing interests in relation to this paper?  
 
If you can answer no to all of the  above, write 'I declare that I have no competing interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing interests  
 
I agree to the open peer review policy of the journal. I understand that my name will  be included 
on my report to the authors and, if the manuscript is accepted for publication, my named report 
including any attachments I upload will be posted on the website along with the authors' 
responses. I agree for my report to be made available unde r an Open Access Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ).  I understand that any comments 
which I do not wish to be included in my named report can be included  as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
assistant