The Gut-brain Axis: How Microbiota Influence Mental Health and Neurological Function View PDF

Tanish Ram Kolli
Medicine, Kamineni Academy Of Medical Sciences And Research Centre, Hyderabad, Telangana, India
Diya Lini
Medicine, East European University, Georgia
Aningi Yashwanth
Medicine, GSL Medical College, Rajahmundry, Andhra Pradesh, India
Bhargavi Srinivasan
Medicine, Bharati Vidyapeeth Deemed University Medical College, Pune, Maharashtra, India

Published on: 2025-11-10

Abstract

The gut-brain axis (GBA) represents a critical bidirectional communication network linking the gut microbiota with mental and neurological health, necessitating a comprehensive review to consolidate emerging evidence and elucidate its therapeutic potential. Growing research underscores the role of microbial metabolites, neurotransmitter regulation, and immune pathways in influencing conditions such as depression, anxiety, and neurodegenerative diseases, yet gaps remain in translating these findings into clinical applications. This review addresses the need to integrate multidisciplinary insights into the GBA, offering a foundation for future research and interventions targeting gut-brain interactions. The review highlights the pivotal role of gut microbiota in producing neuroactive compounds, such as short-chain fatty acids (SCFAs) and serotonin, which modulate brain function and behavior. It examines dietary influences, including fiber-rich and fermented foods, in shaping microbial diversity and mental health outcomes. Additionally, the mechanisms of neural, endocrine, and immune pathways in gut-brain communication are explored, alongside clinical evidence linking dysbiosis to psychiatric and neurological disorders. Emerging therapeutic strategies, such as psychobiotics, fecal microbiota transplantation, and personalized nutrition, are discussed as promising interventions. The review also synthesizes findings from key studies on dietary patterns, microbial metabolites, and their impact on cognitive and emotional health. By consolidating this evidence, the review provides a holistic understanding of the GBA’s role in health and disease. Future research should prioritize longitudinal and interventional studies to establish causal relationships between gut microbiota and brain function. Standardized methodologies for microbiome analysis and larger, diverse cohorts are needed to enhance reproducibility and clinical relevance. Investigations into the efficacy of microbiome-targeted therapies, including combinations of diet, probiotics, and pharmacologic agents, will be critical for advancing treatment paradigms. Ultimately, unraveling the complexities of the GBA may pave the way for innovative, personalized approaches to mental and neurological healthcare.

Keywords

Gut microbiota, Gut-brain axis, Mental health, Microbial metabolites, Neuroinflammation, Psychobiotics

Introduction

The GBA represents a complex and dynamic communication network between the gastrointestinal (GI) tract and the central nervous system (CNS) [1-3]. This bidirectional signaling system is increasingly recognized for its role in influencing mental health and neurological function. The gut microbiota, a diverse community of microorganisms residing in the GI tract, plays a pivotal role in this interaction, affecting everything from mood and behavior to cognitive processes and neurological disorders [4-6]. The GBA represents a complex bidirectional communication network whereby the gut microbiota influences neurological function and mental health [7-9]. Recent literature underscores the pivotal role of microbial metabolites, neurotransmitter regulation, and dietary components in modulating this axis [10, 11].

Dietary factors, particularly fiber intake, have been linked to cognitive processes through their impact on the microbiota [12-14]. McGuinness et al. [15] highlights that dietary fiber influences brain health by shaping the composition and activity of gut microbiota, which in turn affects cognitive function. Similarly, dietary supplements and natural compounds are recognized for their potential to modulate neurological health, emphasizing diet’s importance in neurological disease management [16]. Microbial metabolites such as SCFAs are identified as key mediators within the GBA. Cheng et al. [17] describe SCFAs-producing bacteria as promising psychobiotics capable of exerting neuroprotective effects by modulating neuroinflammation and neuronal function. Kim [18] further elaborates that these metabolites influence cell-to-cell interactions in the CNS, affecting mood, cognition, and behavior by promoting brain cell maturation and suppressing inflammatory signals.

The production of neurotransmitters by gut microbiota is another critical mechanism through which microbiota influences mental health [19-21]. Gurow et al. [22] expands on this by reviewing how microbiota-regulated neurotransmitters directly impact brain function and neurological disorders. The developmental stage of the microbiota also bears significance. Beretta et al. [23] note that the neonatal period is crucial for establishing a healthy microbiota, which has long-term implications for cognitive development and mental health. This early colonization influences the bidirectional communication within the GBA, affecting future neurological outcomes.

Emerging research explores the molecular interactions between gut microbes and the CNS, including immune modulation and neurochemical signaling. Bakshi et al. [10] describes how microbial metabolites, neurotransmitters, and immune factors collectively contribute to gut-brain communication, offering insights into potential therapeutic strategies for psychiatric and neurological disorders. Abavisani et al. [24] further investigates how microbiotaproduced neurotransmitters influence social behaviors, highlighting the microbiota’s broader impact on human behavior. The literature converges on the understanding that the gut microbiota, through its metabolic activities and neurochemical production, plays a fundamental role in maintaining neurological health and influencing mental health disorders. The modulation of this GBA via diet, probiotics, and early microbiota development presents promising avenues for therapeutic intervention [10, 11].