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Horwell et al. Microbiome Res Rep 2025;4:1 https://dx.doi.org/10.20517/mrr.2024.32 Page 13 of 20

consistently breastfeeding has the largest effect size. Moreover, the available evidence suggests that as a
single variable, it provides a significant and long-lasting health benefit to the infant. After breastfeeding
stops, other environmental cues, such as diet, geography, and exposure to soil, start to influence the
microbiome to a greater degree. This period of early life, the window of opportunity, appears key to priming
the immune system and avoiding chronic inflammatory states in later life. These modifiable variables show
growing promise for future clinical utility for a microbiome-based public health intervention. As our
methodology improves, higher resolution analysis should make it possible to dissect specific strain-level
configurations as well as the non-bacterial species of the microbiome, and the ecosystems they originate
from, to enable us to fully understand how the microbiome influences the normal development of the
immune and metabolic systems in humans.

DECLARATIONS
Authors’ contributions
Conceptualization, writing - original draft, visualization: Horwell E
Writing - review & editing: Bearn P, Cutting SM

Availability of data and materials
Not applicable.

Financial support and sponsorship
This work was supported by funding from the UK Medical Research Council (MRC) under grant number
(MR/R026262/1 to Cutting SM). The doctoral fellowship of Dr Edward Horwell was paid for by Ashford
and St Peter’s NHS Foundation Trust (UK).

Conflicts of interest
Cutting SM is the CEO of SporeGen Ltd and has no financial gain in this publication. There are no other
conflicts of interest to declare.

Ethical approval and consent to participate
Not applicable.

Consent for publication
Not applicable.

Copyright
© The Author(s) 2024.

REFERENCES
1. Whipps JM, Lewis K, Cooke RC. Mycoparasitism and plant disease control. In: Burge MN, editors. Fungi in biological control
systems. Manchester University Press; 1988.p.161-187. Available from: https://books.google.com/books?hl=zh-CN&lr=&id=
qoK7AAAAIAAJ&oi=fnd&pg=PR7&dq=Fungi+in+biological+control+systems&ots=ZGZywqBQQc&sig=
SF3yncFR8kM6WBVld-jY1Ymmxec#v=onepage&q=Fungi%20in%20biological%20control%20systems&f=false. [Last accessed on
13 Sep 2024].
2. Berg G, Rybakova D, Fischer D, et al. Microbiome definition re-visited: old concepts and new challenges. Microbiome 2020;8:103.
DOI PubMed PMC
3. Ursell LK, Metcalf JL, Parfrey LW, Knight R. Defining the human microbiome. Nutr Rev 2012;70 Suppl 1:S38-44. DOI PubMed
PMC
4. Grice EA, Segre JA. The skin microbiome. Nat Rev Microbiol 2011;9:244-53. DOI PubMed PMC
5. Morowitz MJ, Carlisle EM, Alverdy JC. Contributions of intestinal bacteria to nutrition and metabolism in the critically ill. Surg Clin
North Am 2011;91:771-85. DOI PubMed PMC