Gut Microbiota in Anxiety and Depression: Unveiling the Relationships and Management Options

Abstract

The gut microbiota is critical for maintaining human health and the immunological system. Several neuroscientific studies have shown the significance of microbiota in developing brain systems. The gut microbiota and the brain are interconnected in a bidirectional relationship, as research on the microbiome–gut–brain axis shows. Significant evidence links anxiety and depression disorders to the community of microbes that live in the gastrointestinal system. Modified diet, fish and omega-3 fatty acid intake, macro- and micro-nutrient intake, prebiotics, probiotics, synbiotics, postbiotics, fecal microbiota transplantation, and 5-HTP regulation may all be utilized to alter the gut microbiota as a treatment approach. There are few preclinical and clinical research studies on the effectiveness and reliability of various therapeutic approaches for depression and anxiety. This article highlights relevant research on the association of gut microbiota with depression and anxiety and the different therapeutic possibilities of gut microbiota modification.

Probiotics as modulators of gut-brain axis for cognitive development

“…Studies have demonstrated that gut bacteria can produce neurotransmitters and other signaling chemicals that affect brain function and development ( Morais et al, 2020 ; Chen et al, 2021 ). Recent studies detailed the associations between GM, mental health, and psychological diseases and disorders including anxiety and depression ( Kumar et al, 2023 ). Genetics, nutrition, environment, and early life experiences play a role in mental health and development via GM.…”

“…Additionally, it has been claimed that inflammatory states are linked to diseases like depression and anxiety. The GBA is thought to be responsible for this phenomenon ( Kumar et al, 2023 ).…”

“…GM may impact host health and is regulated by various factors such as stress, age, food, and host genetics ( Long-Smith et al, 2020 ). The gut and brain communicate through a bidirectional communication network, known as the gut-brain axis (GBA) ( Kumar et al, 2023 ). GM dysbiosis may alter brain structure, brain vascular physiology, and blood-brain barrier (BBB) permeability which may cause neurological disorders and cognitive impairment ( Zhu et al, 2020 ).…”

The effect of psychoactive bacteria, Bifidobacterium longum Rosell®-175 and Lactobacillus rhamnosus JB-1, on brain proteome profiles in mice

“…The effects of the intestinal microbiome on the nervous system are usually multifaceted and include its effect on the sensory nerve fibres, including the vagus nerve, which mediate transmission of information to the CNS and decrease the perception of visceral pain (Wang and Kasper 2014 ; Moloney et al 2016 ; Mitrea et al 2022 ). Interestingly, disturbances in the intestinal microbiome can also be associated with mood disorders, depression, and anxiety, which has been demonstrated in human subjects with irritable bowel syndrome (Cryan and O’Mahony 2011 ; Kumar et al 2023 ). One of the strategies currently promoted for restoring the microbiological balance of the intestines is diet supplementation with probiotics containing selected strains of various microbial species (Hemarajata and Versalovic 2013 ).…”

Shared biological mechanisms of depression and obesity: focus on adipokines and lipokines

“…In addition, there is increasing evidence that the microbial community of the entire gastrointestinal tract (gut microbiota) is related to depressive disorders [30]. Multiple lines of evidence suggest that the gut microbiota is participating in the progression of obesity and related co-morbidities [30][31][32][33][34][35][36]. The neuroplasticity hypothesis, suggesting that the antidepressant effect can be regulated by modulating synaptic plasticity in hippocampal neurons and thus affecting structural plasticity in neural networks, is also the hypothesis applied in the study of the rapid antidepressant effect of ketamine [21,37].…”