Review for 10.1186/s12876-025-04140-2 (2025)

Title: Impact of Microplastics on the Human Gut Microbiome: A Systematic Review of
Microbial Composition, Diversity, and Metabolic Disruptions
Version: 2 Date: 13 May 2025
Reviewer:  Robert Mkuye
Reviewer's report:
Microplastics and Impacts on Human Gut Microbiome: A Systematic Review on Microbiota
Composition, Diversity, and Metabolic Disruptions
The manuscript is timely, well-organized, and addresses an increasingly important public
health concern, microplastics (MPs), on the human gut microbiome. The systematic review
thoroughly explores the effects of MPs on microbial composition, diversity, and metabolic
activity, providing a valuable synthesis of current literature. The methodology is rigorous,
adhering to PRISMA guidelines, which enhances the transparency and reproducibility of the
review process. The authors’ responses to previous comments are satisfactory and reflect serious
consideration for publication. Nevertheless, few areas require further attention and refinement:
1.  The title is informative but could benefit from slight refinement for conciseness and clarity.
Consider one of the following alternatives:
Impact of Microplastics on the Human Gut Microbiome: A Systematic Review of Microbial
Composition, Diversity, and Metabolic Disruptions or Microplastics and Their Impact on the
Human Gut Microbiome: A Systematic Review of Microbial Composition, Diversity, and
Metabolic Disruptions
2. The terms "MPs" (microplastics) and "PRISMA" are used in the abstract without first being
spelled out. Please provide their full forms upon first use to ensure clarity for readers unfamiliar
with these abbreviations.
3. While the abstract summarizes the review’s findings effectively, it would be strengthened by
more explicitly stating the implications of these findings for human health. This will enhance
the relevance and impact of the review.
4. The introduction provides useful context and emphasizes the growing importance of studying
microplastics. However, it does not clearly articulate the existing knowledge gaps, the guiding
research questions, or a strong justification for conducting this systematic review. However, this
doesn’t mean that this manuscript isn’t worth of pyblication, but it means absence of this details
might limit its flow and clarity. Consider revising the introduction to explicitly state: 1. What
specific knowledge gaps the review aims to address/ highlight, 2. The central research questions
guiding the review, and 3. Why this systematic review is needed at this point in time
Methodology
5. While the review synthesizes findings from various studies, it is unclear whether the included
studies adhered to ethical standards [such as did the studies obtained in this review have ethical
approval(s) or informed consent(s)]. Even if the review itself does not require approval, it is good
practice to report whether the original studies included in the analysis complied with ethical
guidelines, considerimg the fact that these studies involved human beings (volunteers). Consider
adding a brief note on this in the methodology or Results and discussion sections.
Results and discussion
6. L 292–294, The sentence reads: “…the abundance of Prevotella abundance…”, please revise
this redundancy for clarity.
7. in Table 2, consider adding a column summarizing the key findings of each study listed. This
will improve readability and help readers quickly understand each study’s contribution.
8. consider adding footnotes below your Tables to provide full forms of abbreviations and any
necessary explanatory details not included within the table.
9. Consider relocating the limitations section to appear immediately before the conclusion.
Additionally, enhance the discussion of limitations by explaining how each identified limitation
may influence the interpretation or generalizability of the review’s findings.
10. Ensure consistent use of abbreviations throughout the manuscript. For example,
“microplastics” and “MPs” appear to be used interchangeably. Once the abbreviation is
introduced, use it consistently.