The dark side of resilience: unveiling hidden dynamics of the intestinal microbiota in horses- An agroecological solution

Abstract

The gut microbiota, a complex community of microorganisms in the digestive tract, plays a pivotal role in animal health and welfare. While it adapts rapidly to environmental changes, stress-related disturbances can cause shifts that are difficult to reverse, increasing allostatic load and impacting overall fitness. The gut-brain axis plays a role in this dynamic. Our research shows that horses kept in individual stalls, without access to pasture or group socialization, fed with highly concentrated diets, and subjected to intense training and competition, experience significant chronic stress. This chronic stress is linked to alterations in microbial diversity and composition within the gut. Furthermore, the intestinal microbiota of these stressed animals exhibits resilience, meaning that despite modification attempts, it returns to its original state. This stability poses a major obstacle to recovery, preventing a reorganization towards a more balanced and beneficial microbial state for the host. Applying agroecological principles, by allowing horses to graze freely and socialize over extended periods, can help reduce the stress and promote a diverse intestinal microbiota, ultimately contributing to their health and overall well-being.