Trace Metals in Modern Technology and Human Health: A Microbiota Perspective on Cobalt, Lithium, and Nickel

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript "Trace Metals in Modern Technology and Human Health: A Microbiota Perspective on Cobalt, Lithium, and Nickel" presents a literature review on role of the trace elements in human health through influence the gut microbiota. The review is comprehensive, relevant to the field of the composition and functioning of gut microbiome. The review contains clear, correct and reliable statements. The review identifies a gap in knowledge of a role of trace elements in gut microbiome. The manuscript is original, based on the comprehensive literature analysis, and discloses perspectives to further studies of trace elements as key modulators of gut microbiome and human health including gut-brain axis functioning. Special attention is devoted to detailed review of effects of the trace elements in different doses to gut microbiota. The cited references include mostly recent publications (within the last 10 years). All citations are relevant. Level of self-citing is insignificant. All statements and conclusions drawn coherent and supported by the listed citations.

However, the manuscript needs some major and minor corrections.

 

Major corrections

1. To make the review more comprehensive it is crucial to provide in Introduction data on the information search. Particularly, which services were used by the author for searching relevant articles. How many relevant sources were found on the influence cobalt, lithium and nickel the gut microbiota. And which years were included into this search.
2. The author cited two reviews on the heavy metals. Concerning to this, it is necessary to explain, what new information is contained in this review in contrast to previous ones.
3. The manuscript contains a lot of repeats. Particularly, Text in lines115-124 is very similar to the lines 125-137. It is recommended to combine these parts and remove repeats. Also repeats are numerous in other fragments of text (lines 155-171 and lines 182-207)
4. Absence of illustrations makes the review too unpresentable. I recommend to add tables providing description of trace elements effects in excessive doses or their deficiency to gut microbiota and its representatives.

 

 

Minor correction

Line 82 and everywhere. All Latin names of all prokaryotic taxa (not only species!) should be marked with Italic font according to the recommendation of the International Code of Nomenclature of Prokaryotes (https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.005585) See: Chapter 4. Advisory notes A. Suggestions for Authors and Publishers

Author Response

#1 The manuscript "Trace Metals in Modern Technology and Human Health: A Microbiota Perspective on Cobalt, Lithium, and Nickel" presents a literature review on role of the trace elements in human health through influence the gut microbiota. The review is comprehensive, relevant to the field of the composition and functioning of gut microbiome. The review contains clear, correct and reliable statements. The review identifies a gap in knowledge of a role of trace elements in gut microbiome. The manuscript is original, based on the comprehensive literature analysis, and discloses perspectives to further studies of trace elements as key modulators of gut microbiome and human health including gut-brain axis functioning. Special attention is devoted to detailed review of effects of the trace elements in different doses to gut microbiota. The cited references include mostly recent publications (within the last 10 years). All citations are relevant. Level of self-citing is insignificant. All statements and conclusions drawn coherent and supported by the listed citations.

However, the manuscript needs some major and minor corrections.

 

 

 We sincerely thank the reviewer for their insightful comments, constructive suggestions, and thoughtful remarks, which have greatly contributed to enhancing the clarity and scientific quality of our manuscript.

 

Major corrections

1. To make the review more comprehensive it is crucial to provide in Introduction data on the information search. Particularly, which services were used by the author for searching relevant articles. How many relevant sources were found on the influence cobalt, lithium and nickel the gut microbiota. And which years were included into this search.

 

We would like to clarify that this manuscript is a narrative review, which does not follow the formal methodology of a systematic review (e.g., PRISMA). Nevertheless, to ensure clarity and transparency, we have now added a brief section in the introduction that outlines the literature search strategy used to prepare this review.

 

Specifically, we conducted a non-systematic but comprehensive search of the scientific literature using the following databases: PubMed, Web of Science, Scopus, and Google Scholar. The search included publications in English published between 2000 and 2024, using combinations of keywords such as “cobalt”, “lithium”, “nickel”, “gut microbiota”, “intestinal microbiome”, and “trace metals”. Articles were selected based on their scientific relevance, originality, and contribution to the understanding of interactions between trace metals and the gut microbiota. Additional references were identified through snowballing by examining the reference lists of relevant papers. This methodology has now been briefly described in the revised manuscript (see Introduction).

 

 

2. The author cited two reviews on the heavy metals. Concerning to this, it is necessary to explain, what new information is contained in this review in contrast to previous ones.

 

Thank you for your remark. Among the  300+ reviews published these last 10 years, the two cited reviews are among the few that provide a general overview of heavy metals and their effects on microbiota.

 

3. The manuscript contains a lot of repeats. Particularly, Text in lines115-124 is very similar to the lines 125-137. It is recommended to combine these parts and remove repeats. Also repeats are numerous in other fragments of text (lines 155-171 and lines 182-207)

 

We have carefully revised the manuscript to eliminate these repetitions. Specifically, the text discussing cobalt’s dual role has been consolidated into a single, more concise paragraph that retains the key concepts without restating them. Similarly, the sections addressing lithium’s inflammatory effects and gut-brain axis interactions have been streamlined to remove overlaps and improve clarity.

 

4. Absence of illustrations makes the review too unpresentable. I recommend to add tables providing description of trace elements effects in excessive doses or their deficiency to gut microbiota and its representatives.

We have added four figures to visually summarize and clarify key concepts. Additionally, we included a new table that provides a comparative overview of the effects of cobalt, lithium, and nickel—both in deficiency and excess—on gut microbiota composition, functionality, and representative microbial taxa. These additions aim to make the review more accessible and informative for readers.

 

Minor correction

Line 82 and everywhere. All Latin names of all prokaryotic taxa (not only species!) should be marked with Italic font according to the recommendation of the International Code of Nomenclature of Prokaryotes

 

In accordance with the International Code of Nomenclature of Prokaryotes, we have revised the manuscript to ensure that all Latin names of prokaryotic taxa—including not only species but also genera and higher taxonomic ranks—are now presented in italics throughout the text.

 

Reviewer 2 Report

Comments and Suggestions for Authors

The paper presented to me for review, “Trace Metals in Modern Technology and Human Health: A Microbiota Perspective on Cobalt, Lithium, and Nickel” is a review paper. 
The authors in the publication attempted to discuss the issue of trace elements on the human microbiota. The paper analyzed the effects of 3 trace elements on the microbiota (Cobalt, Lithium, and Nickel).
In the paper, the authors did not present the databases they used in preparing the publication.  In addition, no details of the methodology for preparing the publication were provided.
In my opinion, the authors drew appropriate and valuable conclusions from the reviewed scientific literature.
In their paper, the authors included 40 items of current scientific references on the subject under discussion. This amount seems to be too modest for a review paper.
In my opinion, the authors have fully elaborated the issue that is the subject of the publication. 
However, the publication is missing at least a few figures that would surely increase the value of the publication. 
In summary, the paper is interesting and can be qualified for publication after expanding the cited references and taking into account comments on the methodology of the study. It is also recommended to include several figures related to the topic of the work.

 

Author Response

#2 The paper presented to me for review, “Trace Metals in Modern Technology and Human Health: A Microbiota Perspective on Cobalt, Lithium, and Nickel” is a review paper. 
The authors in the publication attempted to discuss the issue of trace elements on the human microbiota. The paper analyzed the effects of 3 trace elements on the microbiota (Cobalt, Lithium, and Nickel).

We sincerely thank the reviewer for their insightful comments, constructive suggestions, and thoughtful remarks, which have greatly contributed to enhancing the clarity and scientific quality of our manuscript.

In the paper, the authors did not present the databases they used in preparing the publication.  In addition, no details of the methodology for preparing the publication were provided.

 

Specifically, we conducted a non-systematic but comprehensive search of the scientific literature using the following databases: PubMed, Web of Science, Scopus, and Google Scholar. The search included publications in English published between 2000 and 2024, using combinations of keywords such as “cobalt”, “lithium”, “nickel”, “gut microbiota”, “intestinal microbiome”, and “trace metals”. Articles were selected based on their scientific relevance, originality, and contribution to the understanding of interactions between trace metals and the gut microbiota. Additional references were identified through snowballing by examining the reference lists of relevant papers. This methodology has now been briefly described in the revised manuscript (see Introduction).

 

In my opinion, the authors drew appropriate and valuable conclusions from the reviewed scientific literature.

We sincerely appreciate the reviewer’s positive assessment. We are pleased that our conclusions were found to be appropriate and valuable, and we thank the reviewer

In their paper, the authors included 40 items of current scientific references on the subject under discussion. This amount seems to be too modest for a review paper.
In my opinion, the authors have fully elaborated the issue that is the subject of the publication. 

Regarding the number of references, while the manuscript currently includes 51 citations, we understand the importance of providing a comprehensive overview in a review article. We have added several recent and relevant publications to further strengthen the scientific foundation of the review.

 

However, we would like to point out that the number of available studies specifically addressing the interactions between cobalt, lithium, and nickel with the microbiota—especially all three elements combined—is currently limited. As of our latest literature search (covering 2000–2024), fewer than 220 publications address these interactions in any microbiota context, and even fewer explore mechanistic or comparative perspectives across all three elements.

However, the publication is missing at least a few figures that would surely increase the value of the publication. 

Thank you for your feedback. We have now added 4 figures to enhance the clarity and overall value of the publication.

 

In summary, the paper is interesting and can be qualified for publication after expanding the cited references and taking into account comments on the methodology of the study. It is also recommended to include several figures related to the topic of the work.

Thank you for your positive feedback and valuable recommendations. We have revised the manuscript accordingly.

 

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

The manuscript "Trace Metals in Modern Technology and Human Health: A Microbiota Perspective on Cobalt, Lithium, and Nickel" presents a literature review on role of the trace elements in human health through influence the gut microbiota. The review is comprehensive, relevant to the field of the composition and functioning of gut microbiome. The review contains clear, correct and reliable statements. The review identifies a gap in knowledge of a role of trace elements in gut microbiome. The manuscript is original, based on the comprehensive literature analysis, and discloses perspectives to further studies of trace elements as key modulators of gut microbiome and human health including gut-brain axis functioning. Special attention is devoted to detailed review of effects of the trace elements in different doses to gut microbiota. The cited references include mostly recent publications (within the last 10 years). All citations are relevant. Level of self-citing is insignificant. All statements and conclusions drawn coherent and supported by the listed citations.

The authors corrected almost all improper points, except for the following.

The author cited two reviews on the heavy metals. Concerning to this, it is necessary to explain, what new information is contained in this review in contrast to previous ones.

Authors response: Thank you for your remark. Among the  300+ reviews published these last 10 years, the two cited reviews are among the few that provide a general overview of heavy metals and their effects on microbiota.

Sorry for this misunderstanding. In fact, here I asked the authors to explain differences of their own review from the two reviews on the heavy metals published recently.

Author Response

Sorry for this misunderstanding. In fact, here I asked the authors to explain differences of their own review from the two reviews on the heavy metals published recently.

Thank you for your clarification, and we apologize for the initial misunderstanding. Our review differs from the two cited works by focusing specifically on cobalt, lithium, and nickel, three trace metals that are less commonly addressed in the context of microbiota. Unlike previous reviews that provide general overviews, we explore both the toxic and potential therapeutic roles of these metals, highlight recent mechanistic insights, and identify specific research gaps. These distinctions are now briefly clarified in the introduction to better position our contribution within the existing literature.