Soil microbiomes should be included in One Health goals: Study

Ignoring soil microbiomes and their role may lead to pandemics

By Himanshu Nitnaware
Published: Tuesday 04 July 2023
These microbiomes provide a habitat for microorganisms that benefit the environment by delivering important ecosystem and host functions. Representative photo:

A group of soil experts and researchers have called for including soil microbiomes under the One Health goals that function at the nexus of human, wildlife and the shared environment health. 

One Health approach recommends global strategies to identify and manage the spread of infectious diseases and antimicrobial resistance (AMR).

Soil microbiomes play a crucial role in maintaining healthy water and environmental stability. Moreover, they underpin global food security that eventually affects the overall sustainability of terrestrial life in multiple ways, the experts said in a study published in the journal Nature Communications on June 3, 2023.

These microbiomes provide a habitat for microorganisms that benefit the environment by delivering important ecosystem and host functions. But they also work as a reservoir of human pathogens that induce antibiotic resistance genes (ARGs) and are sources of organic and inorganic pollutants.

Soil microbiomes impact human and animal immune systems by interacting with them through food chains. They also directly influence the quality of the environment through air and water.

Soil, for instance, “is a direct source of plant microbiomes, including beneficial and pathogenic microorganisms. Grazing herbivores are exposed to soil microbiomes via direct ingestion or the consumption of plant microbiomes, which provides a microbial source for the gut microbiome that can impact overall health and immune-system priming,” the study noted.

Organic waste like plant litter and debris such as gravel, sand and others deliver microorganisms back to the soil, thereby closing the microbial loop, the researchers noted. However, any disruption in this can lead to diseases in the host. 

Soil microbiomes also hold reservoirs for crucial microbial hazards of human, plant and animal pathogens. Soil-borne pathogens such as Yersinia pestis, Clostridium botulinum and Bacillus anthracis are present in soil across the globe. They cause hundreds of millions of infections each year via direct or indirect interactions with human, animal and plant food cycles. 

The researchers fear such disruption can lead to an endemic or pandemic, depending on varying microbial virulence and ecological, social as well as environmental conditions.

Previous evidence showed that soil microbiomes have assisted in transferring Salmonella enterica serotype type, responsible for typhoid, from soil to plants and eventually to consumable fruits and seeds. Moreover, it found that soil microbiomes are responsible for the development and spread of AMR — one of the biggest threats to global public health. 

The scientists recommend an integrated and interdisciplinary five-step approach among global bodies to fill the gaps and overcome the challenges.

They suggested the establishment of a knowledge-hub network by integrating the United Nations Global Soil Partnership (UNGSP) and organisations such as the World Health Organization, Food and Agriculture Organization, UNEP,  World Organisation for Animal Health, Consultative Group on International Agricultural Research, International Network of Soil Biodiversity and International Network of Soil Pollution among others for data collection, knowledge sharing and making policy recommendations. 

It further recommended integrating, storing and sharing soil microbiome data to fill gaps in understanding the distribution of soil-borne pathogens and ARGs worldwide. Such efforts could prove useful in devising an automated system to detect and flag human pathogens. The information could benefit policymakers to chalk policies and provide crucial insights on the potential microbial threats in soil systems.

International agencies such as UNGSP, Consultative Group on International Agricultural Research and One Health High-Level Expert Panel (OHHLEP) can coordinate with global expertise to initiate periodic soil assessments relevant to One Health, the researchers noted.

Knowledge could be shared with the Intergovernmental Panel on Climate Change, the Intergovernmental Platform on Biodiversity and Ecosystem Services and the global research community.

“It will be needed to integrate different environmental models (for example, climate, socioecology and land) with epidemiological models to forecast future risks associated with human pathogens, food safety and pollutants,” the paper stated.

The five-step approach also includes developing a coordinated mechanism that periodically and systematically engages concerned stakeholders, including the public, to highlight the critical role soil microbiomes play in One Health.

The final step addresses the barriers or challenges faced in coordinating with the agencies and the effective collection, facilitation, storage and sharing of data. It appeals to different political and global economic situations to join hands to achieve the same.

The study suggested restructuring and reorganising the current system to smoothen the process, efficient data sharing and integration.

“The OHHLEP must be expanded to include soil health and microbiome experts, and resource distribution must be improved as a critical means to support the efficient and effective implementation of activities and principles of the One Health approach,” the study noted.

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