Mass spectrometry insight into environmental chemical exposome and metabolome in the microbiota-gut-brain axis

The microbiota–gut–brain axis represents a critical pathway through which health and disease states are influenced by complex interactions between the central nervous system and the gastrointestinal tract. Environmental exposures play a key role in modulating this axis, with a diverse array of chemical compounds, including both endogenous metabolome and exogenous chemical exposome. Understanding these interactions requires advanced analytical techniques capable of characterizing the large number of compounds involved. Mass spectrometry (MS) has emerged as a cutting-edge tool in this area, offering profound insights into the chemical dynamics of the microbiota–gut–brain axis. MS-based non-targeted analysis have proved valuable in exploring the environmental chemical exposome and its impact on the metabolome. These methods are instrumental in identifying and quantifying a wide range of structurally diverse substances, which traditional targeted analyses might miss. Non-targeted analyses facilitate the discovery of known and unknown pollutants and metabolites, enhancing our understanding of how environmental factors influence metabolic pathways and contribute to health outcomes. This paper provides a comprehensive review of recent advances in mass spectrometry, focusing on non-targeted techniques and their applications in the study of the microbiota-gut-brain axis. It highlights the growing importance of these methodologies in compound discovery and environmental exposure assessment. By integrating findings from cutting-edge research, this review aims to elucidate how mass spectrometry can further enhance our knowledge of the intricate relationships between environmental exposures and metabolic alterations, ultimately contributing to human and environmental health.