The gut-microbiome in adult Attention-deficit/hyperactivity disorder - A Meta-analysis.

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition that persists into adulthood in the majority of individuals. While the gut-microbiome seems to be relevant for ADHD, the few publications on gut-microbial alterations in ADHD are inconsistent, in the investigated phenotypes, sequencing method/region, preprocessing, statistical approaches, and findings. To identify gut-microbiome alterations in adult ADHD, robust across studies and statistical approaches, we harmonized bioinformatic pipelines and analyses of raw 16S rRNA sequencing data from four adult ADHD case-control studies (N=312, N=305).

Gut microbiota composition links to variation in functional domains across psychiatric disorders.

Objective: Changes in microbial composition are observed in various psychiatric disorders, but their specificity to certain symptoms or processes remains unclear. This study explores the associations between the gut microbiota composition and the Research Domain Criteria (RDoC) domains of functioning, representing symptom domains, specifically focusing on stress-related and neurodevelopmental disorders in patients with and without psychiatric comorbidity.

Methods: The gut microbiota was analyzed in 369 participants, comprising 272 individuals diagnosed with a mood disorder, anxiety disorder, attention deficit/hyperactivity disorder, autism spectrum disorder, and/or substance use disorder, as well as 97 psychiatrically unaffected individuals.

The gut-microbiome in adult Attention-deficit/hyperactivity disorder - A Meta-analysis.

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition that persists into adulthood in the majority of individuals. While the gut-microbiome seems to be relevant for ADHD, the few publications on gut-microbial alterations in ADHD are inconsistent, in the investigated phenotypes, sequencing method/region, preprocessing, statistical approaches, and findings. To identify gut-microbiome alterations in adult ADHD, robust across studies and statistical approaches, we harmonized bioinformatic pipelines and analyses of raw 16S rRNA sequencing data from four adult ADHD case-control studies (N =312, N =305).

A systematic review exploring the association between the human gut microbiota and brain connectivity in health and disease.

A body of pre-clinical evidence shows how the gut microbiota influence brain functioning, including brain connectivity. Linking measures of brain connectivity to the gut microbiota can provide important mechanistic insights into the bi-directional gut-brain communication. In this systematic review, we therefore synthesized the available literature assessing this association, evaluating the degree of consistency in microbiota-connectivity associations.

Serotonin Transporter (SERT) Expression Modulates the Composition of the Western-Diet-Induced Microbiota in Aged Female Mice.

The serotonin transporter (SERT), highly expressed in the gut and brain, is implicated in metabolic processes. A genetic variant of the upstream regulatory region of the gene encoding SERT, the so-called short (s) allele, in comparison with the long (l) allele, results in the decreased function of this transporter, altered serotonergic regulation, an increased risk of psychiatric pathology and type-2 diabetes and obesity, especially in older women. Aged female mice with the complete (: KO) or partial (: HET) loss of SERT exhibit more pronounced negative effects following their exposure to a Western diet in comparison to wild-type (: WT) animals.

The role of the gut microbiota in patients with Kleefstra syndrome.

Kleefstra Syndrome (KS) is a rare monogenetic syndrome, caused by haploinsufficiency of the euchromatic histone methyl transferase 1 (EHMT1) gene, an important regulator of neurodevelopment. The clinical features of KS include intellectual disability, autistic behavior and gastrointestinal problems. The gut microbiota, an important modifier of the gut-brain-axis, may constitute an unexplored mechanism underlying clinical KS variation.

Impulsivity is longitudinally associated with healthy and unhealthy dietary patterns in individuals with overweight or obesity and metabolic syndrome within the framework of the PREDIMED-Plus trial.

Background: Few studies have analyzed the associations between impulsivity and dietary patterns. Some of them have shown a cross-sectional inverse relationship between impulsivity and healthy diet scores, whereas others reported a positive association with unhealthy dietary assessments. We aimed to examine longitudinal associations of impulsivity trait with adherence to healthy and unhealthy dietary patterns in older participants at high risk of cardiovascular disease over 3 years of follow-up.

The gut microbiome as mediator between diet and its impact on immune function.

Dietary habits may affect inflammatory status in humans. Here we explore this interaction as well as the potential mediating role of the gut microbiome (GM), given that the GM is both involved in processing of dietary components and influences the immune system. A cross-sectional analysis of a sample of 482 healthy participants (207 males and 275 females) was performed.

The Effects of Intermittent Fasting on Brain and Cognitive Function.

The importance of diet and the gut-brain axis for brain health and cognitive function is increasingly acknowledged. Dietary interventions are tested for their potential to prevent and/or treat brain disorders. Intermittent fasting (IF), the abstinence or strong limitation of calories for 12 to 48 h, alternated with periods of regular food intake, has shown promising results on neurobiological health in animal models.

Correction: Szopinska-Tokov et al. Investigating the Gut Microbiota Composition of Individuals with Attention-Deficit/Hyperactivity Disorder and Association with Symptoms. 2020, , 406.

The authors wish to make the following correction to this paper [...

Probiotics-induced changes in gut microbial composition and its effects on cognitive performance after stress: exploratory analyses.

Stress negatively affects cognitive performance. Probiotics remediate somatic and behavioral stress responses, hypothetically by acting on the gut microbiota. Here, in exploratory analyses, we assessed gut microbial alterations after 28-days supplementation of multi-strain probiotics (EcologicBarrier consisting of Lactobacilli, Lactococci, and Bifidobacteria in healthy, female subjects (probiotics group n = 27, placebo group n = 29).

Catecholaminergic modulation of the cost of cognitive control in healthy older adults.

Catecholamines have long been associated with cognitive control and value-based decision-making. More recently, we have shown that catecholamines also modulate value-based decision-making about whether or not to engage in cognitive control. Yet it is unclear whether catecholamines influence these decisions by altering the subjective value of control.

The Role of the Gut-Brain Axis in Attention-Deficit/Hyperactivity Disorder.

Genetic and environmental factors play a role in the cause and development of attention-deficit/hyperactivity disorder (ADHD). Recent studies have suggested an important role of the gut-brain axis (GBA) and intestinal microbiota in modulating the risk of ADHD. Here, the authors provide a brief overview of the clinical and biological picture of ADHD and how the GBA could be involved in its cause.

Neuro-Cognitive Effects of Acute Tyrosine Administration on Reactive and Proactive Response Inhibition in Healthy Older Adults.

The aging brain is characterized by altered dopamine signaling. The amino acid tyrosine, a catecholamine precursor, is known to improve cognitive performance in young adults, especially during high environmental demands. Tyrosine administration might also affect catecholamine transmission in the aging brain, thereby improving cognitive functioning.

Dose-Dependent Effects of Oral Tyrosine Administration on Plasma Tyrosine Levels and Cognition in Aging.

The effects of tyrosine on plasma response and cognition in aging are unknown. We assessed the dose-dependent response to tyrosine administration in older adults in both plasma tyrosine concentrations and working memory performance. In this double blind randomized cross-over trial 17 older adults (aged 60-75 years) received a single administration of 100, 150, or 200 mg/kg body weight of tyrosine.

Contrasting neural effects of aging on proactive and reactive response inhibition.

Two distinct forms of response inhibition may underlie observed deficits in response inhibition in aging. We assessed whether age-related neurocognitive impairments in response inhibition reflect deficient reactive inhibition (outright stopping) or also deficient proactive inhibition (anticipatory response slowing), which might be particularly evident with high information load. We used functional magnetic resonance imaging in young (n = 25, age range 18-32) and older adults (n = 23, 61-74) with a stop-signal task.

High frequency rTMS; a more effective treatment for auditory verbal hallucinations?

The great majority of studies on repetitive transcranial magnetic stimulation (rTMS) as a therapeutic tool for auditory verbal hallucinations (AVH) have used 1-Hz stimulation with inconsistent results. Recently, it has been suggested that 20-Hz rTMS has strong therapeutic effects. It is conceivable that this 20-Hz stimulation is more effective than 1-Hz stimulation.

Dopaminergic modulation of distracter-resistance and prefrontal delay period signal.

Dopamine has long been implicated in the online maintenance of information across short delays. Specifically, dopamine has been proposed to modulate the strength of working memory representations in the face of intervening distracters. This hypothesis has not been tested in humans.

A setup for administering TMS to medial and lateral cortical areas during whole-brain FMRI recording.

Stimulating brain areas with transcranial magnetic stimulation (TMS) while concurrently and noninvasively recording brain activity changes through functional MRI enables a new range of investigations about causal interregional interactions in the human brain. However, standard head-coil arrangements for current methods for concurrent TMS-functional MRI somewhat restrict the cortical brain regions that can be targeted with TMS because space in typical MR head coils is limited. Another limitation for concurrent TMS-functional MRI approaches concerns the estimation of the precise stimulation site, which can limit the interpretation of the activity changes induced by TMS and increase the variability of the stimulation effects.

Transcranial magnetic stimulation and functional MRI reveal cortical and subcortical interactions during stop-signal response inhibition.

Stopping an action requires suppression of the primary motor cortex (M1). Inhibitory control over M1 relies on a network including the right inferior frontal cortex (rIFC) and the supplementary motor complex (SMC), but how these regions interact to exert inhibitory control over M1 is unknown. Specifically, the hierarchical position of the rIFC and SMC with respect to each other, the routes by which these regions control M1, and the causal involvement of these regions in proactive and reactive inhibition remain unclear.

Expectations and violations: delineating the neural network of proactive inhibitory control.

The ability to stop a prepared response (reactive inhibition) appears to depend on the degree to which stopping is expected (proactive inhibition). Functional MRI studies have shown that activation during proactive and reactive inhibition overlaps, suggesting that the whole neural network for reactive inhibition becomes already activated in anticipation of stopping. However, these studies measured proactive inhibition as the effect of stop-signal probability on activation during go trials.