A systematic review of the effects of gut microbiota depletion on social and anxiety-related behaviours in adult rodents: Implications for translational research.

The microbiota-gut-brain axis is associated with several behaviours, including those relevant to anxiety or sociability in rodents, however, no conceptual framework has yet been available. Summary of the effects of antibiotic-mediated gut microbiota depletion on anxiety and sociability is essential to both inform further preclinical investigations and to guide translational research into human studies. The main objective is to examine the role of gut microbiota depletion on anxiety and sociability in rodents, and to consider how the findings can be translated to inform the design of research in humans.

The live biotherapeutic Blautia stercoris MRx0006 attenuates social deficits, repetitive behaviour, and anxiety-like behaviour in a mouse model relevant to autism.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterised by deficits in social behaviour, increased repetitive behaviour, anxiety and gastrointestinal symptoms. The aetiology of ASD is complex and involves an interplay of genetic and environmental factors. Emerging pre-clinical and clinical studies have documented a potential role for the gut microbiome in ASD, and consequently, the microbiota represents a potential target in the development of novel therapeutics for this neurodevelopmental disorder.

Inflammation, Lifestyle Factors, and the Microbiome-Gut-Brain Axis: Relevance to Depression and Antidepressant Action.

Depression is considered a major public health concern, where existing pharmacological treatments are not equally effective across all patients. The pathogenesis of depression involves the interaction of complex biological components, such as the immune system and the microbiota-gut-brain axis. Adjunctive lifestyle-oriented approaches for depression, including physical exercise and special diets are promising therapeutic options when combined with traditional antidepressants.

Improvements in sleep indices during exam stress due to consumption of a .

Targeting the gut microbiome as an effective therapeutic strategy for psychological disorders has shown promise in recent years. Variation in the composition of the microbiota and restoration of a stable microbiome using targeted interventions (psychobiotics) including Bifidobacteria have shown promise in pre-clinical studies, but more human data is required on the potential health benefits of these live microorganisms Bifidobacterium including 1714 has been shown to dampen the effects of acute stress in humans. However, its effects over a period of prolonged stress have not been examined.

Microbiota from young mice counteracts selective age-associated behavioral deficits.

The gut microbiota is increasingly recognized as an important regulator of host immunity and brain health. The aging process yields dramatic alterations in the microbiota, which is linked to poorer health and frailty in elderly populations. However, there is limited evidence for a mechanistic role of the gut microbiota in brain health and neuroimmunity during aging processes.

Gut Susceptibility to Viral Invasion: Contributing Roles of Diet, Microbiota and Enteric Nervous System to Mucosal Barrier Preservation.

The gastrointestinal lumen is a rich source of eukaryotic and prokaryotic viruses which, together with bacteria, fungi and other microorganisms comprise the gut microbiota. Pathogenic viruses inhabiting this niche have the potential to induce local as well as systemic complications; among them, the viral ability to disrupt the mucosal barrier is one mechanism associated with the promotion of diarrhea and tissue invasion. This review gathers recent evidence showing the contributing effects of diet, gut microbiota and the enteric nervous system to either support or impair the mucosal barrier in the context of viral attack.

Impact of host and environmental factors on β-glucuronidase enzymatic activity: implications for gastrointestinal serotonin.

The gastrointestinal tract houses a reservoir of bacterial-derived enzymes that can directly catalyze the metabolism of drugs, dietary elements and endogenous molecules. Both host and environmental factors may influence this enzymatic activity, with the potential to dictate the availability of the biologically-active form of endogenous molecules in the gut and influence inter-individual variation in drug metabolism. We aimed to investigate the influence of the microbiota, and the modulation of its composition, on fecal enzymatic activity.

No effect of a musical intervention on stress response to venepuncture in a neonatal population.

Aim: To investigate the effect of a musical intervention on neonatal stress response to venepuncture as measured by salivary cortisol levels and pain profile scores.

Methods: In a randomised control crossover trial, participants were randomised to both a control arm (sucrose) and intervention arm (sucrose and music) for routine venepuncture procedures. Salivary swabs were collected at baseline, 20 minutes post-venepuncture and 4 hours post-venepuncture.

Mid-life microbiota crises: middle age is associated with pervasive neuroimmune alterations that are reversed by targeting the gut microbiome.

Male middle age is a transitional period where many physiological and psychological changes occur leading to cognitive and behavioural alterations, and a deterioration of brain function. However, the mechanisms underpinning such changes are unclear. The gut microbiome has been implicated as a key mediator in the communication between the gut and the brain, and in the regulation of brain homeostasis, including brain immune cell function.

Psychosocial stress and inflammation driving tryptophan breakdown in children and adolescents: A cross-sectional analysis of two cohorts.

Background: Tryptophan breakdown is an important mechanism in several diseases e.g. inflammation and stress-induced inflammation have been associated with the development of depression via enhanced tryptophan breakdown.

Protein Malnutrition During Juvenile Age Increases Ileal and Colonic Permeability in Rats.

Protein malnutrition can lead to morphological and functional changes in jejunum and ileum, affecting permeability to luminal contents. Regarding the large intestine, data are scarce, especially at juvenile age. We investigated whether low-protein (LP) diet could modify ileal and colonic permeability and epithelial morphology in young rats.

What goes around comes around: novel pharmacological targets in the gut-brain axis.

The gut and the brain communicate bidirectionally through anatomic and humoral pathways, establishing what is known as the gut-brain axis. Therefore, interventions affecting one system will impact on the other, giving the opportunity to investigate and develop future therapeutic strategies that target both systems. Alterations in the gut-brain axis may arise as a consequence of changes in microbiota composition (dysbiosis), modifications in intestinal barrier function, impairment of enteric nervous system, unbalanced local immune response and exaggerated responses to stress, to mention a few.

Short-term effects of Poly(I:C) on gut permeability.

The intestinal barrier function depends on an adequate response to pathogens by the epithelium. Toll-like receptor 3 (TLR-3) recognizes double-stranded RNA, a virus-associated molecular pattern. Activation of TLR-3 with Poly(I:C), a synthetic agonist, modulates tissue repair and permeability in other epithelia; however, the effects of local luminal TLR-3 agonists on gut barrier function are unknown.