One Health, One Microbiome: The Invisible Network Shaping Our World

Every step we take, every breath we inhale, and every glass of water we drink brings us into contact with trillions of microorganisms. These microbes live on our skin, in our gut, in animals, soils, freshwater, and oceans. According to the One Health, One Microbiome framework, they do not exist in isolation. Instead, they form a single, interconnected biological system that links human, animal, and environmental health.

Once this perspective is adopted, it becomes difficult to view health as a purely human concern. Inspired by the review article “One Health, One Microbiome,” this post explores the deep microbial connections that bind our species to the wider world and the consequences of disrupting these invisible bonds.

When Balance Is Lost‍

In the open-access review paper “One Health, One Microbiome” (Microbiome 2025), the authors explain that a healthy microbiome acts as a natural shield through colonisation resistance, where diverse microbes compete for space and nutrients to block harmful bacteria. When disrupted by antibiotics, poor nutrition, pollution, or disease, the microbiome enters dysbiosis, marked by reduced diversity and expansion of opportunistic and antimicrobial resistant organisms. The authors illustrate this across systems. Undernourished children carry more ESBL producing bacteria, maternal antibiotics reduce microbial transfer to newborns by about 50 percent, fungicide exposed soils lose beneficial microbes, and stressed coral reef microbiomes become more disease prone. Across all domains, the message is clear. When microbial balance breaks, disease and antimicrobial resistance (AMR) spread more easily.

Antimicrobial Resistance Beyond Hospitals‍

AMR is often seen as a hospital problem, but the review shows it is a broader ecological issue. Resistant bacteria and resistance genes are found not only in clinics, but also in livestock, companion animals, food systems, wastewater, soils, and surface waters. Genomic studies summarised in the paper reveal overlapping resistance genes across humans, animals, and environmental samples from the same regions. At the household level, people and their pets can carry highly similar resistant strains. In agricultural settings, workers, animals, and farm associated environments share resistance genes linked to mobile genetic elements, enabling rapid spread between bacteria. These findings demonstrate that AMR spreads through everyday microbial exchange, following the same ecological pathways that connect One Health domains.

Climate Change as an Accelerator‍

The paper also highlights how climate change intensifies these microbial dynamics. Rising temperatures influence microbial activity, while floods and extreme weather events redistribute pathogens and resistance genes through water, soil, and air. Increased pathogen loads have been detected in environments affected by major flooding events.

Drought alters soil microbiomes and plant microbe interactions, while urbanisation is associated with reduced exposure to environmental microbial diversity. Climate change does not create antimicrobial resistance, but it accelerates the ecological conditions that allow resistant organisms to spread and persist.

Why This Matters‍

The implications extend far beyond medicine. The review shows that antimicrobial resistance threatens food production, livestock systems, and economic stability, especially in regions reliant on agriculture and with limited healthcare. Global projections cited in the paper estimate millions of deaths annually and substantial economic losses if AMR remains uncontrolled.

Importantly, the paper also highlights the potential of microbiomes as part of the solution. Healthy microbial communities can enhance crop resilience to drought, suppress plant diseases, support coral health under heat stress, and influence efficiency and emissions in livestock systems.

One Network, One Responsibility‍

The One Health, One Microbiome concept conveys a clear message. Human health, animal health, and environmental health are inseparable because they are connected through a shared microbial world.

Antimicrobial resistance is a warning sign of what happens when this system is pushed beyond balance, and climate change further amplifies these risks. Understanding and protecting microbiomes across all domains is therefore essential, not only for health, but for the stability of the planet itself. We are already part of this invisible network. The challenge now is learning how to protect it wisely.

For a deeper, evidence-rich exploration of the One Health, One Microbiome concept, read the full review paper here: https://doi.org/10.1186/s40168-025-02231-6

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