Food Fight: Competition and Cooperation over Nutrients in the Gut-Brain Axis and Their Consequences for Health and Behavior

The gut microbiome and host are continuously engaged in a negotiation for essential nutrients, and this dynamic interplay fundamentally shapes both health and behavior. Despite the central role of these interactions, a critical question remains unsolved: what determines whether the nutritional exchanges between host and microbes result in benefits or detriments to the host? Nutrients in the gut are sourced from dietary intake, but their availability is further impacted by digestion efficiency, microbial biosynthesis and consumption, host absorption capacity, and internal physiological state. As research demonstrates, the same microbial species can synthesize vitamins in fiber-rich settings, yet switch to competing for amino acids when protein is limited, or may provide metabolic support under malnutrition yet deplete crucial micronutrients in other conditions. These context-dependent shifts illustrate that it is the nutrient landscape—rather than diet alone—that governs whether host-microbe relationships will support or undermine host physiology. However, the underlying mechanisms guiding these conditional outcomes remain unresolved.This Research Topic aims to examine how nutrient competition and cooperation between host and microbiome specifically impact neuronal function, health, and behavior. Although there is a growing recognition of gut-brain axis dysfunction’s association with numerous neuropsychiatric conditions, we lack a detailed mechanistic understanding of how nutrient allocation translates into physiological and psychological outcomes. Central questions remain, such as: when do microbes switch from producing beneficial neuroactive metabolites to competing for neurotransmitter precursors? What factors shift the balance from physiological to pathological? How do specific patterns of nutrient dysregulation present as distinct psychiatric or cognitive phenotypes? The goal is to move beyond cataloging associations and toward uncovering the conditional logic and mechanistic determinants that underlie these complex nutritional relationships and their effects on the brain.The scope of this Research Topic is centered on studies that reveal the mechanisms and contextual rules governing when, why, and how nutrient dynamics between host and microbiome shift between cooperation and competition, and how these shifts impact neurophysiology and behavior. We welcome contributions that, but are not limited to, the following themes:o Unexpected metabolic trade-offs in host-microbiome nutrient interactionso Identification of tipping points where small changes yield disproportionate physiological or psychological effectso Challenges to existing assumptions about beneficial versus harmful microbial taxao State-dependent effects of dietary or microbiome-targeted interventionso Establishment of causal links between specific nutrient imbalances and neuropsychiatric or cognitive outcomeso Utilization of metabolomics, metagenomics, stable isotope tracing, gnotobiotic models, and multi-omics integration to address these phenomenao Application of computational models to predict host-microbiome nutrient dynamicsWe welcome mechanistic studies, computational models, human trials, and technological innovations employing advanced analytical methodologies as part of this Research Topic. Topic editors: Gili Ezra, Dagmara Zlotkowska, JIA LI Source: https://www.frontiersin.org/research-topics/79399/food-fight-competition-and-cooperation-over-nutrients-in-the-gut-brain-axis-and-their-consequences-for-health-and-behavior