Siobhain M O'Mahony

University College Cork | UCC · Department of Anatomy and Neuroscience

Objective The objective of this scoping review is to review the research evidence regarding the impact of perinatal maternal stress on the maternal and infant gut and human milk microbiomes. Introduction Perinatal stress which refers to psychological stress experienced by individuals during pregnancy and the postpartum period is emerging as a publ...

Persistent post-surgical pain (PPSP) is defined as pain which continues after a surgical operation in a significant form for at least three months (and is not related to pre-existing painful conditions). PPSP is a common, under-recognised, and important clinical problem which affects millions of patients worldwide. Preventative measures which are c...

Pregnancy is a transformative period marked by profound physical and emotional changes, with far-reaching consequences for both mother and child. Emerging research has illustrated the pivotal role of a mother's diet during pregnancy in influencing the prenatal gut microbiome and subsequently shaping the neurodevelopment of her offspring. The intric...

Hypertensive disorders of pregnancy, including pre-eclampsia, are a leading cause of serious and debilitating complications that affect both the mother and the fetus. Despite the occurrence and the health implications of these disorders there is still relatively limited evidence on the molecular underpinnings of the pathophysiology. An area that ha...

Empathetic relationships and the social transference of behaviours have been shown to occur in humans, and more recently through the development of rodent models, where both fear and pain phenotypes develop in observer animals. Clinically, observing traumatic events can induce ‘trauma and stressor‐related disorders’ as defined in the DSM 5. These d...

Endometriosis is a chronic inflammatory condition affecting one in ten women and those assigned female at birth, defined by the presence of endometrial-like tissue outside the uterus. It is commonly associated with pain, infertility, and mood disorders, and is often comorbid with other chronic pain conditions, such as irritable bowel syndrome. Rece...

Background Studies indicate that gut microbiota is related to neurodevelopmental and behavioral outcomes. Accordingly, early gut microbiota composition (GMC) has been linked to child temperament, but research is still scarce. The aim of this study was to examine how early GMC at 2.5 months is associated with child negative and fear reactivity at 8...

Many parts of the animal and human body host groups of bacteria, viruses and fungi that together are known as the microbiome. Microbiomes do not cause disease but are important for the healthy working of many systems in the body, including for reproduction and fertility. While the microbiome that lives in a reproductive tract play the most direct r...

Anatomy is an important subject in medical and allied health education, and there are many pedagogical tools that can be used to teach anatomy. Traditional methods of teaching anatomy, such as cadaveric dissection are considered the “gold-standard”, however technologies such as interactive 3D visualisations apps and Augmented Reality (AR) are incre...

Selective serotonin reuptake inhibitors (SSRIs) are the most popular antidepressant medications used to manage perinatal mood disturbances, yet our understanding of how they affect the microbiome-gut-brain axis of the mother and offspring is limited. The purpose of this study was to determine how peripartum SSRI treatment may prevent the effects of...

Visceral hypersensitivity, a hallmark of disorders of the gut‐brain axis, is associated with exposure to early‐life stress (ELS). Activation of neuronal β3‐adrenoceptors (AR) has been shown to alter central and peripheral levels of tryptophan and reduce visceral hypersensitivity. In this study, we aimed to determine the potential of a β3‐AR agonist...

The microbiome-gut-brain axis plays a role in anxiety, the stress response and social development, and is of growing interest in neuropsychiatric conditions. The gut microbiota shows compositional alterations in a variety of psychiatric disorders including depression, generalised anxiety disorder (GAD), autism spectrum disorder (ASD) and schizophre...

Post-embolisation syndrome (PES) is a prevalent complication that occurs in patients following uterine artery embolisation (UAE) for the treatment of uterine fibroids. The aetiology of PES remains incompletely understood, although postulated to result secondary to tissue infarction resulting in release of inflammatory mediators. We followed PRISMA...

Scope: Milk fat globule membrane (MFGM) is an essential component of milk. Bovine MFGM (bMFGM) has been shown to support cognitive development and increase relative concentrations of serum phospholipids. This study investigated bioavailability of bMFGM components after oral administration in two preclinical models to explore whether dietary bMFGM...

Background and Aim Relative to men, women present with pain conditions more commonly. Although consistent differences exist between men and women in terms of physiological pain sensitivity, the underlying mechanisms are incompletely understood and yet could inform the development of effective sex specific treatments for pain. The gut microbiota can...

Sex steroids, derived mainly from gonads, can shape microbiota composition; however, the impact of gonadectomy and sex on steroid production in the gut (i.e., gut steroids), and its interaction with microbiota composition, needs to be clarified. In this study, steroid environment and gut steroidogenesis were analysed by liquid chromatography tandem...

Nutritional approaches have emerged over the past number of years as suitable interventions to ameliorate the enduring effects of early life stress. Maternal separation (MS) is a rodent model of early life stress which induces widespread changes across the microbiota-gut-brain axis. Milk fat globule membrane (MFGM) is a neuroactive membrane structu...

Steroid hormones are essential biomolecules for human physiology as they modulate the endocrine system, nervous function and behaviour. Recent studies have shown that the gut microbiota is directly involved in the production and metabolism of steroid hormones in the periphery. However, the influence of the gut microbiota on levels of steroids actin...

Background The tryptophan-kynurenine pathway is of major interest in psychiatry and is altered in patients with depression, schizophrenia and panic disorder. Stress and immune alterations can impact this system, through cortisol- and cytokine-induced activation. In addition, there is emerging evidence that the kynurenine pathway is associated with...

In this issue of Cell Host & Microbe, Seki et al. (2021) demonstrate an overgrowth of Klebsiella in the gut microbiota of extremely premature infants that is predictive of brain damage. The Klebsiella-associated pro-inflammatory signature suggests that aberrant microbiome-gut-brain axis signaling provokes the disruption of neurodevelopmental trajec...

Stress during critical periods of neurodevelopment is associated with an increased risk of developing stress-related psychiatric disorders which are more common in women than men. Hippocampal neurogenesis (the birth of new neurons) is vulnerable to maternal separation and inflammatory stressors, and emerging evidence suggests that hippocampal neuro...

Recent findings linked gastrointestinal disorders characterized by abdominal pain to gut microbiota composition. The present work aimed to evaluate the power of gut microbiota as a visceral pain modulator and, consequently, the relevance of its manipulation as a therapeutic option in reversing post-inflammatory visceral pain persistence. Colitis wa...

Interactions between the intestinal microbiota, immune system and nervous system are essential for homeostasis in the gut. Inflammasomes contribute to innate immunity and brain-gut interactions, but their role in microbiota-neuro-immune interactions is not clear. Therefore, we investigated the effect of the inflammasome on visceral pain and local a...

In excess of 300 million surgical procedures are undertaken worldwide each year. Despite recognition of the prevalence of postoperative pain, and improvements in pain management techniques, poorly controlled postoperative pain remains a major unresolved challenge globally. An estimated 71% and 51% of patients experience moderate to severe pain afte...

Gut microbiota play a role in certain pain states. Hence, these microbiota also influence somatic pain. We aimed to determine if there was an association between gut microbiota (composition and diversity) and postoperative pain. Patients (n=20) undergoing surgical fixation of distal radius fracture under axillary brachial plexus block were studied....

Visceral hypersensitivity (VH) is a hallmark of many functional gastrointestinal disorders including irritable bowel syndrome and is categorised by a dull, diffuse sensation of abdominal pain. Recently, the gut microbiota has been implicated in visceral hypersensitivity in male mice, but the effects in females has yet to be explored fully. To this...

Prenatal maternal stress that results from general and pregnancy-specific forms of anxiety and depression, ranging in severity from everyday hassles to experiences of traumatic events, adversely impacts neurodevelopment and increases risks for psychopathology in the offspring. To date, the focus of investigations has been on the assessment of facto...

Background The gastrointestinal microbiota has emerged as a key regulator of gut‐brain axis signalling with important implications for neurogastroenterology. There is continuous bidirectional communication between the gut and the brain facilitated by neuronal, endocrine, metabolic, and immune pathways. The microbiota influences these signalling pat...

Within the human gut, we each harbour a unique ecosystem represented by trillions of microbes that contribute to our health and wellbeing. These gut microbiota form part of a complex network termed the microbiota-gut-brain axis along with the enteric nervous system, sympathetic and parasympathetic divisions of the autonomic nervous system, and neur...

Microbes colonize the human body during the first moments of life and coexist with the host throughout the lifespan. Intestinal microbiota and their metabolites aid in the programming of important bodily systems such as the immune and the central nervous system during critical temporal windows of development, with possible structural and functional...

Psychological stress affects maternal gastrointestinal (GI) permeability, leading to low-grade inflammation which can impact negatively on fetal development. We investigated a panel of circulating markers as a biological signature of this stress exposure in pregnant women with and without the stress-related GI disorder irritable bowel syndrome (IBS...

Background Oxidized phospholipid derivatives (OxPAPCs) act as bacterial lipopolysaccharide (LPS)–like damage‐associated molecular patterns. OxPAPCs dose‐dependently exert pro‐ or anti‐inflammatory effects by interacting with several cellular receptors, mainly Toll‐like receptors 2 and 4. It is currently unknown whether OxPAPCs may affect enteric ne...

Visceral hypersensitivity is a hallmark of many functional and stress-related gastrointestinal disorders and there is growing evidence that the gut microbiota may play a role in its pathophysiology. It has previously been shown that early life stress-induced visceral sensitivity is reduced by various probiotic strains of bacteria (including Lactoba...

Background. Recent findings linked gastrointestinal disorders characterized by abdominal pain to gut microbiota composition. The present work aimed to evaluate the power of gut microbiota as a visceral pain modulator and, consequently, the relevance of its manipulation as a therapeutic option in reversing the persistence of visceral hypersensitivit...

Background: Recent findings linked gastrointestinal disorders characterized by abdominal pain to gut microbiota composition. The present work aimed to evaluate the power of gut microbiota as a visceral pain modulator and, consequently, the relevance of its manipulation as a therapeutic option in reversing the persistence of visceral hypersensitivit...

Embalmed human cadavers are an essential educational tool in forensic science and medicine. Cadavers are often embalmed to extend the period they can be used. Qualitative observations such as odours, tissue texture and colour are the only methods currently used by anatomists to assess the decomposition progress of embalmed cadavers. The aim of this...

Chronic stress and ageing are two of the most important factors that negatively affect cognitive processes such as learning and memory across the lifespan. To date, pharmacological agents have been insufficient in reducing the impact of both on brain health, and thus, novel therapeutic strategies are required. Recent research has focused on nutriti...

The microbiota-gut–brain axis is a complex and dynamic multi-directional ‘communication superhighway’ within the body including the central nervous system, the autonomic nervous system, the neuroendocrine and neuroimmune systems, the lymphatic system, the enteric nervous system and the gastrointestinal microbiota. The mechanisms of communication ar...

Nutritional interventions targeting the microbiota‐gut‐brain axis are proposed to modulate stress‐induced dysfunction of physiological processes and brain development. Maternal separation (MS) in rats induces long‐term alterations to behavior, pain responses, gut microbiome and brain neurochemistry. In this study, the effects of dietary interventio...

Pregnancy and early life are characterized by marked changes in body microbial composition. Intriguingly, these changes take place simultaneously with neurodevelopmental plasticity, suggesting a complex dialogue between the microbes that inhabit the gastrointestinal tract and the brain. The purpose of this chapter is to describe the natural traject...

Aim: Chronic stress increases disease vulnerability factors including inflammation, a pathological characteristic potentially regulated by the gut microbiota. We checked the association between the gut microbiome and psychosocial stress in children/adolescents and investigated which stress parameter (negative versus positive emotion, self-report v...

Background: One of the key behavioral phenotypes in infancy are different temperament traits, and certain early life temperament traits have been shown to precede later mental health problems. Differences in the gut microbiota composition (GMC) have been suggested to link with neurodevelopment. For example, toddler temperament traits have been fou...

Aims Infectious health risks are associated with handling human cadavers and to decrease such risks, cadavers are embalmed using different chemicals. The aim of this study is to quantify the amount of microorganisms present in different regions of human cadavers before embalming, after embalming and over a period of eight months. Methods and Resul...

Cadaveric material has long been used to teach anatomy and more recently to train students in clinical skills. The aim of this study was to develop a systematic approach to compare the impact of four embalming solutions on the tissues of human cadavers. To this end, a formalin‐based solution, Thiel, Genelyn and Imperial College London soft‐preserva...

Nutritional interventions targeting the microbiota‐gut‐brain axis may be able to modulate stress‐induced dysfunction of physiological processes and brain development. Maternal separation (MS) stress of rat pups is a robust model of early life stress that induces long‐term alterations to behavior and brain neurochemistry. In this study the effects o...

It has been nearly 30 years since Dr. David Barker first highlighted the importance of prenatal factors in contributing to the developmental origins of adult disease. This concept was later broadened to include postnatal events. It is clear that the interaction between genetic predisposition and early life environmental exposures is key in this reg...

Introduction Cadaveric studies provide a means of safely assessing new technologies and optimizing scanning prior to clinical validation. Reducing radiation exposure in a clinical setting can entail incremental dose reductions to avoid missing important clinical findings. The use of cadavers allows assessment of the impact of more substantial dose...

Objectives The aim of this study is to investigate the impact of different embalming solutions including formalin, Genelyn, Thiel and Imperial College London- Soft Preserving solutions on the quality of radiological images taken from cadavers embalmed with the above mentioned techniques. Materials and methods Two cadavers per embalming technique w...

A growing body of preclinical and clinical evidence supports a relationship between the complexity and diversity of the microorganisms that inhabit our gut (human gastrointestinal microbiota) and health status. Under normal homeostatic conditions this microbial population helps maintain intestinal peristalsis, mucosal integrity, pH balance, immune...

Early life is a period of significant brain development when the brain is at its most plastic and vulnerable. Stressful episodes during this window of development have long-lasting effects on the central nervous system. Rodent maternal separation (MS) is a reliable model of early-life stress and induces alterations in both physiology and behaviour....

Early-life stress is an established risk for the development of psychiatric disorders. Post-weaning isolation rearing of rats produces lasting developmental changes in behavior and brain function that may have translational pathophysiological relevance to alterations seen in schizophrenia, but the underlying mechanisms are unclear. Accumulating evi...

ELife digest The human gut is home to over 100 trillion microbes collectively known as the gut microbiota. These microbes help us to digest food and absorb the nutrients effectively. A diverse and stable community of gut microbes is believed to be important for good health. Recently, it has also become clear that the microbiota can also influence t...

Alterations of the gut microbiota have been associated with stress-related disorders including depression and anxiety and irritable bowel syndrome (IBS). More recently, researchers have started investigating the implication of perturbation of the microbiota composition in neurodevelopmental disorders including autism spectrum disorders and Attentio...

The aim of this study was to determine whether Thiel-embalmed cadavers would provide a useful anatomy teaching tool for topics that cannot be approached using formalin-fixed cadavers such as oral cavity examination and maxillary anesthesia. The suitability of Thiel-embalmed bodies for performing oral examinations was assessed by asking first-year d...

A growing body of preclinical and clinical evidence supports a relationship between the complexity and diversity of the microorganisms that inhabit our gut (human gastrointestinal microbiome) and health status. These microbes can influence centrally regulated emotional behaviour through mechanisms including microbially derived bioactive molecules,...

Irritable bowel syndrome is a functional gastrointestinal disorder, with stress playing a major role in onset and exacerbation of symptoms such as abdominal pain and altered bowel movements. Stress-related disorders including anxiety and depression often precede the development of irritable bowel syndrome and vice versa. Stressor exposure during ea...

The infant gut microbiome is dynamic with radical shifts in its composition occurring during early life. Many factors are capable of influencing this colonization. Disruption of the developmental patterns prior to the attainment of a more stable adult-like gastrointestinal microbiota is increasingly being linked to adverse health outcomes. The impa...

Background: Early-life stress (ELS) is a recognized risk factor for chronic pain disorders, and females appear to be more sensitive to the negative effects of stress. Moreover, estrous cycle-related fluctuations in estrogen levels have been linked with alternating pain sensitivity. Aberrant central circuitry involving both the anterior cingulate c...

Visceral pain is a significant and prevalent feature of several disorders including the functional gastrointestinal disorder, irritable bowel syndrome (IBS). Treatment strategies are limited and often unsatisfactory which has opened up new research avenues into the aetiology of visceral pain. This research has led to an increased appreciation of th...

Introduction: Against a backdrop of ever-changing diagnostic and treatment modalities, stakeholder perceptions (medical students, clinicians, anatomy educators) are crucial for the design of an anatomy curriculum which fulfils the criteria required for safe medical practice. This study compared perceptions of students, practising clinicians, and a...

Females are more likely to experience visceral pain than males, yet mechanisms underlying this sex bias are not fully elucidated. Moreover, pain sensitivity can change throughout the menstrual cycle. Alterations in the glutamatergic system have been implicated in several pain-disorders; however, whether these are sex-dependent is unclear. Thus, we...

Utilizing reality anatomy such as dissection and demonstrating using cadavers has been described as a superior way to create meaning. The chemicals used to embalm cadavers differentially alter the tissue of the human body, which has led to the usage of different processes along the hard to soft-fixed spectrum of preserved cadavers. A questionnaire...

The dopaminergic system is involved in motivation, reward and the associated motor activities. Mesodiencephalic dopaminergic neurons in the ventral tegmental area (VTA) regulate motivation and reward, whereas those in the substantia nigra (SN) are essential for motor control. Defective VTA dopaminergic transmission has been implicated in schizophre...

Maternal separation of rat pups is a robust and reliable model of early life stress that induces long‐term alterations to behavior and brain neurochemistry. These changes are particularly apparent with respect to the microbiota‐gut‐brain axis where probiotic feeding has been shown to ameliorate some of these stress‐induced alterations. It is possib...

Human cadavers have been used for centuries to learn about the human body. Today they still represent a key anatomy learning tool in most Medical Schools. Using reality anatomy such as dissection and demonstrating using cadavers has been described as a superior way to create meaning. To prevent the decomposition of cadavers and to decrease any heal...

Parkinson's disease is the second most common neurodegenerative disorder, affecting 1–2% of the population over 65 years of age. The primary neuropathology is the loss of midbrain dopaminergic neurons, resulting in characteristic motor deficits, upon which the clinical diagnosis is based. However, a number of significant non-motor symptoms (NMS) ar...

An improved understanding of the relationship between anatomy learning performance and approaches to learning can lead to the development of a more tailored approach to delivering anatomy teaching to medical students. This study investigated the relationship between learning style preferences, as measured by Visual, Aural, Read/write, and Kinesthet...

Visceral pain is a global term used to describe pain originating from the internal organs of the body, which affects a significant proportion of the population and is a common feature of functional gastrointestinal disorders (FGIDs) such as irritable bowel syndrome (IBS). While IBS is multifactorial, with no single etiology to completely explain th...