Toward climate-smart livestock: The role of the microbiome in One Health approaches

Abstract Background : Climate change poses critical challenges to global livestock systems, threatening productivity, food security, and environmental sustainability. The ruminant microbiome, particularly the rumen microbial community, plays a vital role in animal health, nutrition, and productivity, while also contributing to greenhouse gas emissions. Framing the microbiome within a One Health perspective highlights its importance for animal well-being, human nutrition, and environmental resilience. Methods : This review synthesizes evidence on the impacts of climate-related stressors, including heat, drought, and feed scarcity on the livestock microbiome. It examines interventions such as probiotics, prebiotics, fecal microbiota transplantation, dietary modifications, and synthetic biology approaches, alongside strategies to inhibit methanogenic archaea. Advances in microbiome analytics, including omics platforms, sensors, and machine learning, are discussed in relation to precision livestock farming and monitoring of animal health and emissions. Results : Findings indicate that microbiome shifts under climate stressors influence both livestock productivity and methane emissions. Meta-analyses and field trials demonstrate that feed and microbial additives and methanogenesis inhibitors can decrease enteric methane emissions by 20–80%, enhance feed conversion efficiency by 5–15%, and sustain milk production under heat stress conditions. While technological innovations enable more precise monitoring, significant gaps remain in understanding host–microbe–climate interactions, and barriers such as technical limitations, regulatory hurdles, and farmer adoption challenges persist. Integrated multi-omics methodologies now elucidate key genes and pathways that regulate fermentation resilience, facilitating precise microbiome engineering via probiotics, bacteriophages, and CRISPR-mediated modulation of methanogens. Beyond biological innovation, microbiome-focused approaches are consistent with international One Health frameworks (FAO–WHO–WOAH), facilitating the mitigation of antimicrobial resistance (AMR), reduction of zoonotic risks, and reporting of greenhouse gas emissions within climate-smart agricultural initiatives. Integrating microbiome metrics into national livestock, AMR, and climate policies can elevate them from experimental instruments to quantifiable sustainability strategies. Conclusion : Overall, this review demonstrates that harnessing the ruminant microbiome has the potential to reduce global agricultural methane emissions by up to 40%, while simultaneously enhancing animal resilience and productivity – positioning the microbiome as a critical biological and policy frontier for climate-smart, One Health-oriented livestock transformation. Microbiome-based strategies offer a promising pathway toward climate-smart livestock systems. Achieving this will require harmonized research methodologies, systems-based multi-omics approaches, cross-sectoral collaboration, and supportive policy frameworks. Integrating microbiome innovations into climate adaptation strategies can strengthen livestock productivity, improve food security, and support environmental resilience. One Health impact statement This review underscores the centrality of the ruminant microbiome at the interface of animal, human, and environmental health. By shaping livestock productivity, methane emissions, and antimicrobial resistance dynamics, microbial communities act as critical levers for sustainable food systems. Integrating microbiome science into livestock management contributes to safer food, reduced zoonotic and AMR risks, and lower greenhouse gas outputs, thereby aligning with the global One Health agenda. Advancing microbiome-based interventions through selective breeding, dietary strategies, and precision livestock farming, offers practical opportunities to strengthen climate resilience, improve animal welfare, and safeguard public health.