This article reviews the current literature on gut health's effects on mental health, focusing on alternative medicine approaches that seek to enhance the gut-brain axis through dietary interventions, probiotics, and other holistic practices.

Introduction

Emerging research highlights a complex interplay between gut health and mental well-being, suggesting that the gastrointestinal (GI) microbiome profoundly influences mental health outcomes. The relationship between gut health and mental health has garnered increasing attention in recent years. Traditionally viewed as separate systems, the gut and the brain are interconnected through the gut-brain axis, which is mediated by biochemical signalling between the gut microbiota and the central nervous system.

The gut-brain axis

The gut-brain axis refers to the bidirectional communication network between the gut microbiome and the brain. This connection is facilitated by various pathways, including:

1. Neurotransmitter production: Gut bacteria synthesise neurotransmitters such as serotonin, dopamine, and gamma-aminobutyric acid (GABA), which are crucial for mood regulation (Yano et al., 2015).
2. Immune system modulation: The gut microbiome influences immune responses, contributing to inflammation that can affect brain function (Gurung et al., 2020).
3.  Vagus nerve: The vagus nerve serves as a critical pathway for gut-brain communication, allowing signals from the gut to influence brain activity directly (Bonaz et al., 2018).

Evidence of gut health's impact on mental health

Numerous studies have supported the link between gut health and mental health. For instance, a systematic review found a correlation between dysbiosis—an imbalance in gut bacteria—and the presence of depressive symptoms (Julian et al., 2020). Moreover, certain probiotics have been shown to reduce anxiety and depression symptoms in clinical populations (Sarkar et al., 2016).

Gut microbiota and mental disorders

Several studies have indicated that particular strains of bacteria may be beneficial for mental health:

1. Lactobacillus and bifidobacterium: These probiotics have been associated with reduced levels of anxiety and depressive symptoms (Jiang et al., 2015).
2. Fermented foods: Diets rich in fermented foods (such as yoghurt, kefir, and sauerkraut) promote gut health and have been linked to improved mood (Ager et al., 2018).

Alternative medicine approaches

Given the evidence linking gut health and mental health, alternative medicine approaches can be employed to improve gut health and, by extension, mental well-being:

1. Dietary interventions

1. Mediterranean diet: Rich in vegetables, fruits, whole grains, and healthy fats, this diet has been associated with a reduced risk of depression (Sanchez-Villegas et al., 2018).
2. Gut-healing foods: Bone broth, fermented vegetables, and fibre-rich foods help promote a healthy microbiome (Wang et al., 2019).

2. Probiotics and prebiotics

1. Use of probiotics: Strains like Lactobacillus rhamnosus and Bifidobacterium longum have shown promise in improving mood and reducing anxiety (Finn et al., 2020).
2. Prebiotics: Foods that feed beneficial gut bacteria (like inulin, found in garlic and onions) can enhance gut health (Slavin, 2013).

3. Mindfulness and stress reduction

1. Mindfulness practices: Meditation and yoga have been reported to reduce symptoms of depression and improve gut microbiota diversity (Keng et al., 2011).
2. Physical activity: Regular exercise promotes a diverse and healthy gut microbiome, contributing to overall mental well-being (Mikulić et al., 2020).

4. Herbal medicine

Certain herbs such as ashwagandha and rhodiola rosea have shown adaptogenic properties, potentially modulating stress responses and impacting gut health (Panossian et al., 2010).

Disclaimer- The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy or position of M3 India.

About the author of this article: Dr Partha Ghosh, BNYS, MD(YS), is a general physician, holistic healing practitioner and a medical writer from Siliguri, Darjeeling.