Reviewer ’s report  
 
Title:  Liver Abscess and Bac teremia Caused by Lactobacillus: Role of Probiotics? Case Report 
and Review of the Literature  
 
Version: 0 Date: 20 Nov 2015 
 
Reviewer:  Alexander  Khoruts  
 
Reviewer’s report:  
 
This is an important case report that should be added to the bod y of literature on po tential 
hazards of probiotics. The weakn ess here is limited forensics. We do not know whether the 
probiotics product contained the identical strain of Lactobaci llus as the patient's abscess. In fact, 
it would have been interested to  document that the specific product used by the patient even had 
live Lactobacillus, as many such  products on the shelf do not. The authors do acknowledge that 
the infection could have been caused by a m ember of commensal microbiota.  The possibility of 
doing a more precise analysis and importance of doing so in future case studies should be noted 
in the report.   
 
 
Minor comments:  
 
* Bottom Page 4 and throughout the manuscript. 'Clostridium difficile' should be 
capitalized and italicized: Clostridium dif ficile.   
 
* Page 5. 'Clostridium difficile' is not a diagnosis. It is an organism. The diagnosis is 'C. 
difficile infection'.  
 
* Page 5.  'gram staining' should be capitalized to 'Gram staining', as the method was 
developed by Hans Christian Gram, a Da nish bacteriologist.  
 
* Page 6, line 58.  Sentence "Some strains of lactobacilli are used as probiotics to restore 
non-pathogenic intestinal flora and decrease digestive colonization with pathogenic bacteria".  
This should be qualified as 'presumably' or ' in hopes for', etc.  It has never been shown that any 
existing probiotic product has restored the composition of gut microbial communities.  
 
* Page 6, line 59.  The sentence stating that probiotics have been shown to have beneficial 
effects in preventing a nd treating some diseases such as antibiotic -associated diarrhea is 
somewhat problematic.  First, there is legitimate debate about the strength of evidence.  Second, 
by definition any product that prevents, treats, or mitigates disease is classified as a d rug, and 
probiotics are not in that category and should not be given the privilege of such claims without 
real hard evidence.  
 
* Page 7, line 16.  "In a systemic review of the safety of probiotics  
* in 2010, all but three trials showed no increase in compl ications related to using 
probiotics" - how many was "all"?  
  
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.  
 
No 
 
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 recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
Not relevant to this manuscript  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Needs some language corrections before being published  
 
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 financially 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 public ation of this manuscript, either now or in the future?  
 
3. Do you hold or 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 you 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 t hat 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 under an Open Access Cr eative 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 comme nts 
to the editors, which will not be published . 
 
I agree to the open peer review policy of the journal  
Reviewer ’s report  
 
Title:  Liver Abscess and Bac teremia Caused by Lactobacillus: Role of Probiotics? Case Report 
and Review of the Literature  
 
Version: 0 Date: 20 Nov 2015 
 
Reviewer:  Alexander  Khoruts  
 
Reviewer’s report:  
 
This is an important case report that should be added to the bod y of literature on po tential 
hazards of probiotics. The weakn ess here is limited forensics. We do not know whether the 
probiotics product contained the identical strain of Lactobaci llus as the patient's abscess. In fact, 
it would have been interested to  document that the specific product used by the patient even had 
live Lactobacillus, as many such  products on the shelf do not. The authors do acknowledge that 
the infection could have been caused by a m ember of commensal microbiota.  The possibility of 
doing a more precise analysis and importance of doing so in future case studies should be noted 
in the report.   
 
 
Minor comments:  
 
* Bottom Page 4 and throughout the manuscript. 'Clostridium difficile' should be 
capitalized and italicized: Clostridium dif ficile.   
 
* Page 5. 'Clostridium difficile' is not a diagnosis. It is an organism. The diagnosis is 'C. 
difficile infection'.  
 
* Page 5.  'gram staining' should be capitalized to 'Gram staining', as the method was 
developed by Hans Christian Gram, a Da nish bacteriologist.  
 
* Page 6, line 58.  Sentence "Some strains of lactobacilli are used as probiotics to restore 
non-pathogenic intestinal flora and decrease digestive colonization with pathogenic bacteria".  
This should be qualified as 'presumably' or ' in hopes for', etc.  It has never been shown that any 
existing probiotic product has restored the composition of gut microbial communities.  
 
* Page 6, line 59.  The sentence stating that probiotics have been shown to have beneficial 
effects in preventing a nd treating some diseases such as antibiotic -associated diarrhea is 
somewhat problematic.  First, there is legitimate debate about the strength of evidence.  Second, 
by definition any product that prevents, treats, or mitigates disease is classified as a d rug, and 
probiotics are not in that category and should not be given the privilege of such claims without 
real hard evidence.  
 
* Page 7, line 16.  "In a systemic review of the safety of probiotics  
* in 2010, all but three trials showed no increase in compl ications related to using 
probiotics" - how many was "all"?  
  
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.  
 
No 
 
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 recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
Not relevant to this manuscript  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Needs some language corrections before being published  
 
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 financially 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 public ation of this manuscript, either now or in the future?  
 
3. Do you hold or 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 you 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 t hat 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 under an Open Access Cr eative 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 comme nts 
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:  Liver Abscess and Bac teremia Caused by Lactobacillus: Role of Probiotics? Case Report 
and Review of the Literature  
 
Version: 0 Date: 20 Nov 2015 
 
Reviewer:  Alexander  Khoruts  
 
Reviewer’s report:  
 
This is an important case report that should be added to the bod y of literature on po tential 
hazards of probiotics. The weakn ess here is limited forensics. We do not know whether the 
probiotics product contained the identical strain of Lactobaci llus as the patient's abscess. In fact, 
it would have been interested to  document that the specific product used by the patient even had 
live Lactobacillus, as many such  products on the shelf do not. The authors do acknowledge that 
the infection could have been caused by a m ember of commensal microbiota.  The possibility of 
doing a more precise analysis and importance of doing so in future case studies should be noted 
in the report.   
 
 
Minor comments:  
 
* Bottom Page 4 and throughout the manuscript. 'Clostridium difficile' should be 
capitalized and italicized: Clostridium dif ficile.   
 
* Page 5. 'Clostridium difficile' is not a diagnosis. It is an organism. The diagnosis is 'C. 
difficile infection'.  
 
* Page 5.  'gram staining' should be capitalized to 'Gram staining', as the method was 
developed by Hans Christian Gram, a Da nish bacteriologist.  
 
* Page 6, line 58.  Sentence "Some strains of lactobacilli are used as probiotics to restore 
non-pathogenic intestinal flora and decrease digestive colonization with pathogenic bacteria".  
This should be qualified as 'presumably' or ' in hopes for', etc.  It has never been shown that any 
existing probiotic product has restored the composition of gut microbial communities.  
 
* Page 6, line 59.  The sentence stating that probiotics have been shown to have beneficial 
effects in preventing a nd treating some diseases such as antibiotic -associated diarrhea is 
somewhat problematic.  First, there is legitimate debate about the strength of evidence.  Second, 
by definition any product that prevents, treats, or mitigates disease is classified as a d rug, and 
probiotics are not in that category and should not be given the privilege of such claims without 
real hard evidence.  
 
* Page 7, line 16.  "In a systemic review of the safety of probiotics  
* in 2010, all but three trials showed no increase in compl ications related to using 
probiotics" - how many was "all"?  
  
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.  
 
No 
 
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 recommended, please specify what aspects require further 
assessment in your comments to the editors.  
 
Not relevant to this manuscript  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Needs some language corrections before being published  
 
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 financially 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 public ation of this manuscript, either now or in the future?  
 
3. Do you hold or 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 you 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 t hat 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 under an Open Access Cr eative 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 comme nts 
to the editors, which will not be published . 
 
I agree to the open peer review policy of the journal  
assistant