Comparative Structural and Compositional Analyses of Cow, Buffalo, Goat and Sheep Cream.

Factors affecting milk and milk fraction composition, such as cream, are poorly understood, with most research and human health application associated with cow cream. In this study, proteomic and lipidomic analyses were performed on cow, goat, sheep and Bubalus bubalis (from now on referred to as buffalo), bulk milk cream samples. Confocal laser scanning microscopy was used to determine the composition, including protein, lipid and their glycoconjugates, and the structure of the milk fat globules. BLAST2GO was used to annotate functional indicators of cream protein. Functional annotation of protein highlighted a broad level of similarity between species. However, investigation of specific biological process terms revealed distinct differences in antigen processing and presentation, activation, and production of molecular mediators of the immune response. Lipid analyses revealed that saturated fatty acids were lowest in sheep cream and similar in the cream of the other species. Palmitic acid was highest in cow and lowest in sheep cream. Cow and sheep milk fat globules were associated with thick patches of protein on the surface, while buffalo and goat milk fat globules were associated with larger areas of aggregated protein and significant surface adsorbed protein, respectively. This study highlights the differences between cow, goat, sheep, and buffalo milk cream, which can be used to support their potential application in functional foods such as infant milk formula.

Inflammasome Signaling Regulates the Microbial-Neuroimmune Axis and Visceral Pain in Mice.

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 and systemic neuroimmune responses after antibiotic-induced changes to the microbiota. Wild-type (WT) and caspase-1/11 deficient (Casp1 KO) mice were orally treated for 2 weeks with an antibiotic cocktail (Abx, Bacitracin A and Neomycin), followed by quantification of representative fecal commensals (by qPCR), cecal short chain fatty acids (by HPLC), pathways implicated in the gut-neuro-immune axis (by RT-qPCR, immunofluorescence staining, and flow cytometry) in addition to capsaicin-induced visceral pain responses. Abx-treatment in WT-mice resulted in an increase in colonic macrophages, central neuro-immune interactions, colonic inflammasome and nociceptive receptor gene expression and a reduction in capsaicin-induced visceral pain. In contrast, these responses were attenuated in Abx-treated Casp1 KO mice. Collectively, the data indicate an important role for the inflammasome pathway in functional and inflammatory gastrointestinal conditions where pain and alterations in microbiota composition are prominent.

A Marine-Derived, Multi-mineral Supplement Influences Bacterial Fermentation and Short Chain Fatty Acid Profile In Vitro.

Aquamin is a calcium-rich multi-mineral supplement derived from the red marine algae, Lithothamnion species. Calcium supplementation has been shown to exert a prebiotic-like effect on the gut microbiota and has been associated with distinct changes in lactate and short chain fatty acid (SCFA) production. Irritable bowel syndrome (IBS) subtype is associated with changes in SCFA levels compared with healthy controls. Using an ex vivo simulation model, and a fecal inoculum from a patient diagnosed with IBS, we evaluated the effects of Aquamin (at 6 and 30 mg/mL) on SCFAs and lactate production, pH and gas production, and human microbiota composition. Our results demonstrate that Aquamin increased SCFA production (acetate and propionate by 8% and 24%, respectively, at 30 mg/mL dose), significantly decreased lactate production (30 mg/mL), and increased colonic fluid pH without inducing changes in colonic gas production or gastrointestinal (GI) microbiota composition. These results indicate that Aquamin may play a role in optimizing GI microbial function in an ex vivo setting.

Bioaccessibility and Bioavailability of a Marine-Derived Multimineral, Aquamin-Magnesium.

Introduction: Magnesium is an essential mineral involved in a range of key biochemical pathways. Several magnesium supplements are present on the market and their degree of bioavailability differs depending on the form of magnesium salt used. Aquamin-Mg is a natural source of magnesium, containing 72 additional trace minerals derived from the clean waters off the Irish coast. However, the in vitro bioaccessibility and bioavailability of Aquamin-Mg in comparison with other supplement sources of magnesium has yet to be tested. Method: Aquamin-Mg, magnesium chloride (MgCl2) and magnesium oxide (MgO) were subjected to gastrointestinal digestion according to the harmonized INFOGEST in vitro digestion method and in vitro bioavailability tested using the Caco-2 cell model. Magnesium concentration was measured by atomic absorption spectrophotometry (AAS). Results: Magnesium recovery from both Aquamin-Mg and MgCl2 was greater than for MgO. Magnesium from all three sources was transported across the epithelial monolayer with Aquamin-Mg displaying a comparable profile to the more bioavailable MgCl2. Conclusions: Our data support that magnesium derived from a marine-derived multimineral product is bioavailable to a significantly greater degree than MgO and displays a similar profile to the more bioavailable MgCl2 and may offer additional health benefits given its multimineral profile.

Mild prenatal hypoxia-ischemia leads to social deficits and central and peripheral inflammation in exposed offspring.

Hypoxic-ischemic encephalopathy (HIE) resulting from intrauterine or perinatal hypoxic-ischemia (HI) is a leading cause of long-term neonatal neurodisability. While most studies of long-term outcome have focused on moderate and severe HIE in term infants, recent work has shown that those with mild HIE may have subtle neurological impairments. However, the impact of mild HI on pre-term infants is much less clear given that pre-term birth is itself a risk factor for neurodisability. Here we show that mild HI insult alters behaviour, inflammation and the corticosterone stress response in a rat model of pre-term HIE. Mild HI exposure led to social deficits in exposed offspring at postnatal day 30, without impairments in the novel object recognition test nor in the open field test. This was also accompanied by elevations in circulating adrenocorticotropic hormone and corticosterone indicating an exaggerated stress response. There were also elevations in il-1ß and il-6 but not tnf-α mRNA and protein in the brain and blood samples. In summary we find that a mild HI exposure leads to social deficits, central and peripheral inflammation, and an abnormal corticosterone response which are three core features of autism spectrum disorder. This shows that mild HI exposure may be a risk factor for an abnormal neurodevelopmental outcome in pre-term offspring.

The microbiome and disorders of the central nervous system.

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 Attention-Deficit Hypersensitivity Disorder (ADHD). In this review we will discuss how the microbiota is established and its functions in maintaining health. We also summarize both pre and post-natal factors that shape the developing neonatal microbiota and how they may impact on health outcomes with relevance to disorders of the central nervous system. Finally, we discuss potential therapeutic approaches based on the manipulation of the gut bacterial composition.

Estrous cycle influences excitatory amino acid transport and visceral pain sensitivity in the rat: effects of early-life stress.

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 cortex (ACC) and the lumbosacral spinal cord has also been implicated in the modulation of visceral pain in clinical and preclinical studies. Here we further investigate changes in visceral pain sensitivity and central glutamatergic systems in rats with respect to estrous cycle and ELS. METHODS: We investigated visceral sensitivity in adult female Sprague-Dawley rats, which had undergone maternal separation (MS) in early life or remained non-separated (NS), by performing colorectal distension (CRD). We also assessed excitatory amino acid uptake through excitatory amino acid transporters (EAATs) in the lumbosacral spinal cord and ACC. RESULTS: NS animals in proestrus and estrus exhibited reduced EAAT uptake and decreased threshold to CRD. Moreover, total pain behaviors were increased in these stages. MS rats exhibited lower pain thresholds and higher total pain behaviors to CRD across all stages of the estrous cycle. Interestingly, cortical EAAT function in MS rats was inhibited in the low estrogen state-an effect completely opposite to that seen in NS rats. CONCLUSIONS: This data confirms that estrous cycle and ELS are significant factors in visceral sensitivity and fluctuations in EAAT function may be a perpetuating factor mediating central sensitization.

Sex-dependent activity of the spinal excitatory amino acid transporter: Role of estrous cycle.

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 aimed to investigate sex differences in the spinal cord glutamate uptake and how it varies across the estrous cycle. The activity of the glutamate transporters, excitatory amino acid transporters (EAATs) was assessed using an ex vivo aspartate radioactive uptake assay in the lumbosacral spinal cord in Sprague-Dawley male and female rats. The gene expression of EAATs, glutamate receptor subunits NR1 and NR2B and the estrogen receptors ERα & ERß in the spinal cord were also analyzed. EAAT activity was lower in females, particularly during the estrus phase, and this was the only cycle stage that was responsive to the pharmacological effects of the EAATs activator riluzole. Interestingly, EAAT1 mRNA expression was lower in high-estrogen and high-ERα states compared to diestrus in females. We conclude that the Spinal EAAT activity in females is different to that in males, and varies across the estrous cycle. Furthermore, the expression levels of estrogen receptors also showed a cycle-dependent pattern that may affect EAATs function and expression.

Microbiota-gut-brain signalling in Parkinson's disease: Implications for non-motor symptoms.

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) are also evident that appear to have a greater impact on the quality of life of these patients. In recent years, it has become increasingly apparent that neurobiological processes can be modified by the bi-directional communication that occurs along the brain-gut axis. The microbiota plays a key role in this communication throughout different routes in both physiological and pathological conditions. Thus, there has been an increasing interest in investigating how microbiota changes within the gastrointestinal tract may be implicated in health and disease including PD. Interestingly α-synuclein-aggregates, the cardinal neuropathological feature in PD, are present in both the submucosal and myenteric plexuses of the enteric nervous system, prior to their appearance in the brain, indicating a possible gut to brain route of "prion-like" spread. In this review we highlight the potential importance of gut to brain signalling in PD with particular focus on the role of the microbiota as major player in this communication.

Visceral Pain and Psychiatric Disorders.

The high comorbidity existing between visceral pain and psychiatric disorders such as depression and anxiety is well documented and it is gaining increasing interest among scientists. When visceral pain and psychiatric disorders are comorbid, they present a more debilitating condition than each disorder alone, impacting significantly on the quality of life of these patients. Despite several groups having shown that an overlapping pathophysiology exists between visceral pain and stress-related disorders the link between them is not clear yet. Moreover, it still remains to be elucidated if psychiatric conditions predispose the individual to develop visceral hypersensitivity or vice versa. The brain-gut-microbiome axis is the bidirectional communication between the CNS and the gastrointestinal tract. Alterations at different levels of this axis have been implicated in both visceral hypersensitivity and psychiatric disorders. Here we give an overview of what it is known about comorbid visceral pain and psychiatric disorders and provide evidence of potential overlapping pathophysiological mechanisms involved. Preclinical models of comorbid visceral pain and stress-related disorders are also discussed.

Preconditioning stimuli induce autophagy via sphingosine kinase 2 in mouse cortical neurons.

Sphingosine kinase 2 (SPK2) and autophagy are both involved in brain preconditioning, but whether preconditioning-induced SPK2 up-regulation and autophagy activation are linked mechanistically remains to be elucidated. In this study, we used in vitro and in vivo models to explore the role of SPK2-mediated autophagy in isoflurane and hypoxic preconditioning. In primary mouse cortical neurons, both isoflurane and hypoxic preconditioning induced autophagy. Isoflurane and hypoxic preconditioning protected against subsequent oxygen glucose deprivation or glutamate injury, whereas pretreatment with autophagy inhibitors (3-methyladenine or KU55933) abolished preconditioning-induced tolerance. Pretreatment with SPK2 inhibitors (ABC294640 and SKI-II) or SPK2 knockdown prevented preconditioning-induced autophagy. Isoflurane also induced autophagy in mouse in vivo as shown by Western blots for LC3 and p62, LC3 immunostaining, and electron microscopy. Isoflurane-induced autophagy in mice lacking the SPK1 isoform (SPK1(-/-)), but not in SPK2(-/-)mice. Sphingosine 1-phosphate and the sphingosine 1-phosphate receptor agonist FTY720 did not protect against oxygen glucose deprivation in cultured neurons and did not alter the expression of LC3 and p62, suggesting that SPK2-mediated autophagy and protections are not S1P-dependent. Beclin 1 knockdown abolished preconditioning-induced autophagy, and SPK2 inhibitors abolished isoflurane-induced disruption of the Beclin 1/Bcl-2 association. These results strongly indicate that autophagy is involved in isoflurane preconditioning both in vivo and in vitro and that SPK2 contributes to preconditioning-induced autophagy, possibly by disrupting the Beclin 1/Bcl-2 interaction.