Abstract
Emerging evidence highlights the pivotal role of the gut-brain axis in mental health, with prebiotics such as galactooligosaccharides (GOS) and xylooligosaccharides (XOS) showing promise in alleviating anxiety and depression. Recent studies demonstrate that these prebiotics can beneficially modulate gut microbiota, increase GABA-producing bacteria, and reduce anxiety-like behaviors in animal models. This review synthesizes current findings on the mechanisms by which GOS and XOS influence the gut-brain axis and discusses their therapeutic potential for mood disorders.
Introduction
The gut-brain axis is a complex communication network linking the gastrointestinal tract and the central nervous system, with the gut microbiota playing a crucial role in modulating brain function and behavior. Anxiety and depression are prevalent mental health disorders, and accumulating research suggests that targeting the gut microbiota with prebiotics may offer novel strategies for their management[1][3][4].
Prebiotics and the Gut-Brain Axis
Prebiotics are nondigestible food components that selectively stimulate the growth and activity of beneficial gut bacteria. GOS and XOS are two such prebiotics that have garnered attention for their effects on mental health. Supplementation with GOS and XOS has been shown to alter gut microbiota composition, notably increasing the abundance of bacteria capable of producing gamma-aminobutyric acid (GABA), a neurotransmitter involved in reducing neuronal excitability and anxiety[1][8][9].
Mechanisms of Action
- Microbiota Modulation: GOS and XOS supplementation leads to an increase in beneficial bacteria such as Bacteroides, which are known GABA producers[8]. This shift in microbial composition can enhance the production of neuroactive metabolites.
- Neuroinflammation Reduction: In mouse studies, prebiotics reduced neuroinflammation and chronic peripheral inflammation, leading to improved anxiety- and depression-like behaviors. These effects were associated with increased levels of acetate and GPR43 in the brain, and decreased pro-inflammatory cytokines[1].
- Intestinal Barrier Function: Improved gut barrier integrity reduces the translocation of inflammatory molecules, further supporting mental health[1][9].
- Neurogenesis and Brain Signaling: Enhanced signaling pathways for neuronal proliferation and survival in the hippocampus and prefrontal cortex have been observed following prebiotic supplementation, suggesting a direct impact on brain health[1].
Evidence from Animal and Human Studies
- Animal Models: In mice fed a high-fat diet, GOS and XOS supplementation reduced anxiety-like behaviors and neuroinflammation, effects comparable to those of fluoxetine, a commonly used antidepressant[1].
- Human Data: While most evidence is currently preclinical, studies suggest that XOS can beneficially shift gut microbiota in humans, with potential implications for metabolic and mental health[6][9].
Discussion
The ability of GOS and XOS to enhance GABA-producing bacteria and reduce neuroinflammation positions them as promising adjuncts in the management of anxiety and depression. These findings support the concept that dietary interventions targeting the gut microbiota can influence brain function and emotional well-being. Further clinical research is needed to establish efficacy and optimal dosing in humans.
Conclusion
Prebiotic supplementation with GOS and XOS offers a promising strategy for modulating the gut-brain axis and improving symptoms of anxiety and depression. By fostering beneficial gut bacteria and reducing neuroinflammation, these compounds may represent a novel, non-pharmacological approach to mental health care[1][8][9].
Citations:
[1] Prebiotics modulate the microbiota-gut-brain axis and ameliorate … https://pubmed.ncbi.nlm.nih.gov/38519181/
[2] The influence of the gut-brain axis on anxiety and depression https://www.sciencedirect.com/science/article/pii/S2225411024000300
[3] The influence of the gut-brain axis on anxiety and depression https://pubmed.ncbi.nlm.nih.gov/38707924/
[4] Prebiotics modulate the microbiota–gut–brain axis and ameliorate … https://www.sciencedirect.com/science/article/abs/pii/S0963996924002230?via%3Dihub
[5] Effect of a Probiotic on Anxiety/Depression through the Gut-Brain Axis https://journals.physiology.org/doi/10.1152/physiol.2024.39.S1.876
[6] Xylooligosaccharide supplementation alters gut bacteria in both … https://pmc.ncbi.nlm.nih.gov/articles/PMC4528259/
[7] Probiotics as modulators of gut-brain axis for cognitive development https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2024.1348297/full
[8] GABA Production by Human Intestinal Bacteroides spp. – Frontiers https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.656895/full
[9] Antioxidant Vitamins and Prebiotic FOS and XOS Differentially Shift … https://pmc.ncbi.nlm.nih.gov/articles/PMC8066074/
