Search Results (39)

The ability of probiotics, comprising live microbiota, to modulate the composition of intestinal microbiomes has been connected to modulation of the central nervous system (Gut–Brain axis), neuroendocrine system (Gut–Skin axis), and immune response (Gut–Immune axis). Less information is known regarding the ability of postbiotics (cell wall components and secreted metabolites derived from live organisms) to regulate host immunity. In the present study, we tested postbiotics comprising single strains of bacteria and yeast (Lactobacillus acidophilus 16axg, Lacticaseibacillus rhamnosus 18fx, Saccharomyces cerevisiae var. boulardii 16mxg) as well as combinations of multiple strains for their ability to stimulate cytokine production by human CD14⁺ monocytes. We quantified cytokine gene and protein expression levels in monocytes following stimulation with postbiotics. Both heat-killed L. acidophilus and L. rhamnosus stimulated naïve monocytes without significant differences between them. Heat-killed S. boulardii stimulated less cytokine production compared to postbiotic bacteria at the same concentration. Interestingly, the addition of heat-killed yeast to heat-killed L. acidophilus and L. rhamnosus resulted in an enhancement of immune stimulation. Thus, heat-killed postbiotics have immune-modulating potential, particularly when bacteria and yeast are combined. This approach may hold promise for developing targeted interventions that can be fine-tuned to modulate host immune response with beneficial health impact. Full article

The aim of this review was to gather pieces of information from available critically evaluated published articles concerning any interplay in which the spleen could be involved. For many years, the spleen has been alleged as an unnecessary biological structure, even though splenomegaly is an objective finding of many illnesses. Indeed, the previous opinion has been completely changed. In fact, the spleen is not a passive participant in or a simple bystander to a relationship that exists between the immune system and other organs. Recently, it has been evidenced in many preclinical and clinical studies that there are close associations between the spleen and other parts of the body, leading to various spleen–organ axes. Among them, the gut–spleen axis, the liver–spleen axis, the gut–spleen–skin axis, the brain–spleen axis, and the cardio-splenic axis are the most explored and present in the medical literature. Such recent sources of evidence have led to revolutionary new ideas being developed about the spleen. What is more, these observations may enable the identification of novel therapeutic strategies targeted at various current diseases. The time has come to make clear that the spleen is not a superfluous body part, while health system operators and physicians should pay more attention to this organ. Indeed, much work remains to be performed to assess further roles that this biological structure could play. Full article

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a complex pathophysiology characterized by intense pruritus, often associated with psychological stress and atopic and non-atopic comorbidities that significantly reduce quality of life. The psychological aspects of AD and the interaction between the mind and body via the skin–brain axis have led to an interest in mind–body therapies (MBT). The aim of this article is, therefore, to reinforce the importance of psychodermatological care in AD. We performed a focused literature review on holistic practices or integrative MBT in AD, including education, cognitive behavioral therapy, habit reversal, meditation, mindfulness, hypnotherapy, eye movement desensitization and reprocessing, biofeedback, progressive muscle relaxation, autonomous sensory meridian response, music therapy, massage, and touch therapy. A multidisciplinary holistic approach with MBT, in addition to conventional pharmacologic antipruritic therapies, to break the itch–scratch cycle may improve AD outcomes and psychological well-being. Although there is a paucity of rigorously designed trials, evidence shows the potential benefits of an integrative approach on pruritus, pain, psychological stress, anxiety, depressive symptoms, and sleep quality. Relaxation and various behavioral interventions, such as habit reversal therapy for replacing harmful scratching with massaging with emollient ‘plus’, may reduce the urge to scratch, while education may improve adherence to conventional therapies. Full article

Brain–gut axis disorders, such as functional dyspepsia and irritable bowel syndrome (traditionally known as functional gastrointestinal disorders), have a prevalence of more than 10% in most countries and affect females more than males. In these disorders, visceral pain and motor alterations affecting the gastrointestinal tract are the key symptoms, together with psychoaffective alterations (depression and anxiety). Two main etiologies are generally recognized for their development: they may be caused by a local inflammatory or infectious problem in the gastrointestinal tract that sensitizes the visceral afferents and lead to central hypersensitization; alternatively, they may be associated with some kind of prolonged psychological stress in vulnerable people or vulnerable periods of life (i.e., due to early life stress). In recent years, studies have focused on the effects of coffee, its components (melanoidins) and its by-products (e.g., coffee spent grounds and coffee silver skin derivatives) on the functions of the brain–gut axis, showing that these products may cause subtle alterations in gastrointestinal motility, visceral sensitivity and behavioral parameters, in a sex-dependent manner. For example, using male rats, we showed that melanoidins and coffee spent grounds slightly accelerate gastrointestinal transit in vivo. In contrast, the regular consumption of instant cascara (IC) did not alter GI transit or behavior in either male or female rats in vivo, but increased both the responses to mechanical intracolonic stimulation and the non-muscarinic responses to electrical field stimulation of the colonic muscle in vitro, specifically in females. These effects need to be taken into account when new functional foods based on coffee and its by-products are to be developed for the general population. Considering the high prevalence of the brain–gut axis disorders and its higher impact on women, with significant symptoms affecting visceral sensitivity and bowel habits, the effects of coffee components and by-products need to be more deeply evaluated in both relevant animal models of brain–gut axis disorders and in clinical trials. Full article

The skin–brain axis has been suggested to play a role in several pathophysiological conditions, including opioid addiction, Parkinson’s disease and many others. Recent evidence suggests that pathways regulating skin pigmentation may directly and indirectly regulate behaviour. Conversely, CNS-driven neural and hormonal responses have been demonstrated to regulate pigmentation, e.g., under stress. Additionally, due to the shared neuroectodermal origins of the melanocytes and neurons in the CNS, certain CNS diseases may be linked to pigmentation-related changes due to common regulators, e.g., MC1R variations. Furthermore, the HPA analogue of the skin connects skin pigmentation to the endocrine system, thereby allowing the skin to index possible hormonal abnormalities visibly. In this review, insight is provided into skin pigment production and neuromelanin synthesis in the brain and recent findings are summarised on how signalling pathways in the skin, with a particular focus on pigmentation, are interconnected with the central nervous system. Thus, this review may supply a better understanding of the mechanism of several skin–brain associations in health and disease. Full article

Plastic production, which exceeds one million tons per year, is of global concern. The constituent low-density polymers enable spread over large distances and micro/nano particles (MNPLs) induce organ toxicity via digestion, inhalation, and skin contact. Particles have been documented in all human tissues including breast milk. MNPLs, especially weathered particles, can breach the blood–brain barrier, inducing neurotoxicity. This has been documented in non-human species, and in human-induced pluripotent stem cell lines. Within the brain, MNPLs initiate an inflammatory response with pro-inflammatory cytokine production, oxidative stress with generation of reactive oxygen species, and mitochondrial dysfunction. Glutamate and GABA neurotransmitter dysfunction also ensues with alteration of excitatory/inhibitory balance in favor of reduced inhibition and resultant neuro-excitation. Inflammation and cortical hyperexcitability are key abnormalities involved in the pathogenic cascade of amyotrophic lateral sclerosis (ALS) and are intricately related to the mislocalization and aggregation of TDP-43, a hallmark of ALS. Water and many foods contain MNPLs and in humans, ingestion is the main form of exposure. Digestion of plastics within the gut can alter their properties, rendering them more toxic, and they cause gut microbiome dysbiosis and a dysfunctional gut–brain axis. This is recognized as a trigger and/or aggravating factor for ALS. ALS is associated with a long (years or decades) preclinical period and neonates and infants are exposed to MNPLs through breast milk, milk substitutes, and toys. This endangers a time of intense neurogenesis and establishment of neuronal circuitry, setting the stage for development of neurodegeneration in later life. MNPL neurotoxicity should be considered as a yet unrecognized risk factor for ALS and related diseases. Full article

The skin is a complex ecosystem colonized by millions of microorganisms, the skin microbiota, which are crucial in regulating not only the physiological functions of the skin but also the metabolic changes underlying the onset of skin diseases. The high microbial colonization together with a low diversity at the phylum level and a high diversity at the species level of the skin is very similar to that of the gastrointestinal tract. Moreover, there is an important communication pathway along the gut–brain–skin axis, especially associated with the modulation of neurotransmitters by the microbiota. Therefore, it is evident that the high complexity of the skin system, due not only to the genetics of the host but also to the interaction of the host with resident microbes and between microbe and microbe, requires a multi-omics approach to be deeply understood. Therefore, an integrated analysis, with high-throughput technologies, of the consequences of microbial interaction with the host through the study of gene expression (genomics and metagenomics), transcription (transcriptomics and meta-transcriptomics), and protein production (proteomics and meta-proteomics) and metabolite formation (metabolomics and lipidomics) would be useful. Although to date very few studies have integrated skin metabolomics data with at least one other ‘omics’ technology, in the future, this approach will be able to provide simple and fast tests that can be routinely applied in both clinical and cosmetic settings for the identification of numerous skin diseases and conditions. It will also be possible to create large archives of multi-omics data that can predict individual responses to pharmacological treatments and the efficacy of different cosmetic products on individual subjects by means of specific allotypes, with a view to increasingly tailor-made medicine. In this review, after analyzing the complexity of the skin ecosystem, we have highlighted the usefulness of this emerging integrated omics approach for the analysis of skin problems, starting with one of the latest ‘omics’ sciences, metabolomics, which can photograph the expression of the genome during its interaction with the environment. Full article

Lactiplantibacillus plantarum is a candidate probiotic that has been included in the list of recommended biological agents for certification by the European Food Safety Authority. It has been found to be widely present in acidic-gruel, yogurt, cheese, kefir, kimchi, and so on. In this article, we have reviewed both preclinical and human studies related to the health promoting effects of L. plantarum that have been published for the past decade. We found that L. plantarum could significantly improve intestinal function, oral as well as skin health, promote neuro as well as immune regulation, and be effective against metabolic diseases, etc. L. plantarum primarily enters the body through the oral cavity and acts on the gastrointestinal tract to effectively improve the intestinal flora. It can affect the female reproductive endocrine system through interaction with estrogen, androgen, insulin, and other hormones, as well as improve the body’s allergic reaction and immunity by regulating Th1/Th2 response. Several prior reports also suggest that this Gram-positive bacterium can promote production and secretion of key neurotransmitters and neural activators in the intestinal tract by regulating the intestinal flora by directly or indirectly affecting the gut–brain axis through modulation of vagus nerve, cytokines, and microbial metabolites, thus relieving stress and anxiety symptoms in adults. This review is the first report describing the health promoting effects of L. plantarum, with the aim of providing a theoretical basis for the development of various beneficial applications of L. plantarum. Full article

The broad range of clinical manifestations and life-threatening infections caused by the Gram-positive bacterium, Streptococcus pyogenes or Group A Streptococcus (GAS), remains a significant concern to public health, with a subset of individuals developing neurological complications. Here, we examined the concurrent neuroimmune effects of subcutaneous GAS infections in an HLA-Class II (HLA) transgenic mouse model of subcutaneous GAS infection. To investigate changes in the skin–brain axis, HLA-DQ8 (DQA1*0301/DQB1*0302) mice (DQ8) were randomly divided into three groups: uninfected controls (No Inf), GAS infected and untreated (No Tx), and GAS infected with a resolution by clindamycin (CLN) treatment (CLN Tx) (10 mg/kg/5 days) and were monitored for 16 days post-infection. While the skin GAS burden was significantly reduced by CLN, the cortical and hippocampal GAS burden in the male DQ8 mice was not significantly reduced with CLN. Immunoreactivity to anti-GAS antibody revealed the presence of GAS bacteria in the vicinity of the neuronal nucleus in the neocortex of both No Tx and CLN Tx male DQ8 mice. GAS infection-mediated cortical cytokine changes were modest; however, compared to No Inf or No Tx groups, a significant increase in IL-2, IL-13, IL-22, and IL-10 levels was observed in CLN Tx females despite the lack of GAS burden. Western blot analysis of cortical and hippocampal homogenates showed significantly higher ionized calcium-binding adaptor-1 (Iba-1, microglia marker) protein levels in No Tx females and males and CLN Tx males compared to the No Inf group. Immunohistochemical analysis showed that Iba-1 immunoreactivity in the hippocampal CA3 and CA1 subregions was significantly higher in the CLN Tx males compared to the No Tx group. Our data support the possibility that the subcutaneous GAS infection communicates to the brain and is characterized by intraneuronal GAS sequestration, brain cytokine changes, Iba-1 protein levels, and concurrent CA3 and CA1 subregion-specific microgliosis, even without bacteremia. Full article

Microbiome supplementation initially targeted the gut microbiota but has since been extended to the skin. A new category, psychobiotics, defined beneficial compounds with a positive action on microbiota, providing benefits to the host’s mental health. Pogostemon cablin leaf extract, proven to alleviate scalp dryness, was clinically evaluated on volunteers presenting dry scalp with flakes. A metagenomics study and sebum production analysis were performed, coupled to flakes scoring. The benefits of Pogostemon cablin leaf extract on emotions were assessed through three neuroscientific methods. Through this study, we proved that the skin microbiota of dry scalp was imbalanced, with increased alpha diversity and decreased Cutibacterium relative abundance compared to oilier skin. After applying our ingredient for one month, microbiota was rebalanced with a decrease in alpha diversity and increase in Cutibacterium relative abundance compared to the initial profile. Microbiota rebalancing led to an increase in scalp sebum and decrease in dry flakes compared to the start of the study. This global rebalancing improved the emotional state of people with scalp dryness who expressed more positive emotions after treatment. Full article

The eyes provide themselves with immune tolerance. Frequent skin inflammatory diseases in young blind people suggest, nonetheless, that the eyes instruct a systemic immune tolerance that benefits the whole body. We tested this premise by using delayed skin contact hypersensitivity (DSCH) as a tool to compare the inflammatory response developed by sighted (S) and birth-enucleated (BE) mice against oxazolone or dinitrofluorobenzene at the ages of 10, 30 and 60 days of life. Adult mice enucleated (AE) at 60 days of age were also assessed when they reached 120 days of life. BE mice displayed exacerbated DSCH at 60 but not at 10 or 30 days of age. AE mice, in contrast, show no exacerbated DSCH. Skin inflammation in 60-day-old BE mice was hapten exclusive and supported by distinct CD8⁺ lymphocytes. The number of intraepidermal T lymphocytes and migrating Langerhans cells was, however, similar between S and BE mice by the age of 60 days. Our observations support the idea that the eyes instruct systemic immune tolerance that benefits organs outside the eyes from an early age. The higher prevalence of inflammatory skin disorders reported in young people might then reflect reduced immune tolerance associated with the impaired functional morphology of the eyes. Full article

Streptococcus pyogenes (Group A Streptococcus, GAS) bacteria cause a spectrum of human diseases ranging from self-limiting pharyngitis and mild, uncomplicated skin infections (impetigo, erysipelas, and cellulitis) to highly morbid and rapidly invasive, life-threatening infections such as streptococcal toxic shock syndrome and necrotizing fasciitis (NF). HLA class II allelic polymorphisms are linked with differential outcomes and severity of GAS infections. The dysregulated immune response and peripheral cytokine storm elicited due to invasive GAS infections increase the risk for toxic shock and multiple organ failure in genetically susceptible individuals. We hypothesized that, while the host immune mediators regulate the immune responses against peripheral GAS infections, these interactions may simultaneously trigger neuropathology and, in some cases, induce persistent alterations in the glial phenotypes. Here, we studied the consequences of peripheral GAS skin infection on the brain in an HLA-II transgenic mouse model of GAS NF with and without treatment with an antibiotic, clindamycin (CLN). Mice expressing the human HLA-II DR3 (DR3) or the HLA-II DR4 (DR4) allele were divided into three groups: (i) uninfected controls, (ii) subcutaneously infected with a clinical GAS strain isolated from a patient with GAS NF, and (iii) GAS-infected with CLN treatment (10 mg/kg/5 days, intraperitoneal). The groups were monitored for 15 days post-infection. Skin GAS burden and lesion area, splenic and hippocampal mRNA levels of inflammatory markers, and immunohistochemical changes in hippocampal GFAP and Iba-1 immunoreactivity were assessed. Skin GAS burden and hippocampal mRNA levels of the inflammatory markers S100A8/A9, IL-1β, IL-33, inflammasome-related caspase-1 (Casp1), and NLRP6 were elevated in infected DR3 but not DR4 mice. The levels of these markers were significantly reduced following CLN treatment in DR3 mice. Although GAS was not detectable in the brain, astrocyte (GFAP) and microglia (Iba-1) activation were evident from increased GFAP and Iba-1 mRNA levels in DR3 and DR4 mice. However, CLN treatment significantly reduced GFAP mRNA levels in DR3 mice, not DR4 mice. Our data suggest a skin–brain axis during GAS NF, demonstrating that peripherally induced pathological conditions regulate neuroimmune changes and gliotic events in the brain. Full article

Type II grass carp reovirus (GCRV-II) with high pathogenicity and infectivity causes severe hemorrhagic disease, which leads to extensive death in the grass carp and black carp aquaculture. However, the early invasion portal remains unclear. In this study, we explored the invasion portal, time, and pathway of GCRV-II by immersion infection in grass carp. Through the detection of the infected grass carp external body surface tissues, most of them could be detected to carry GCRV-II within 45 min except for the skin covered by scales. Further shortening the duration of infection, we proved that GCRV-II rapidly invades through the nostril (especially), gill, and skin on head at only 5 min post-immersion, rather than merely by adhesion. Subsequently, visual localization investigations of GCRV-II were conducted on the nostril, olfactory system (olfactory bulb and olfactory tract), and brain via immunofluorescence microscopy and transmission electron microscopy. We found that few viruses were located in the nostril at 5 min post-immersion infection, while a significantly increased quantity of viruses were distributed in all of the examined tissues at 45 min. Furthermore, the semi-qRT-PCR and Western blotting results of different infection times confirmed that GCRV-II invades grass carp via the nostril–olfactory system–brain axis and then viral replication unfolds. These results revealed the infection mechanism of GCRV-II in terms of the invasion portal, time, and pathway in grass carp. This study aims to understand the invasion mode of GCRV-II in grass carp, thus providing theoretical support for the prevention and control strategies of hemorrhagic disease. Full article

Grape pomace (GP) is a winemaking by-product particularly rich in (poly)phenols and dietary fiber, which are the main active compounds responsible for its health-promoting effects. These components and their metabolites generated at the intestinal level have been shown to play an important role in promoting health locally and systemically. This review focuses on the potential bioactivities of GP in the intestinal environment, which is the primary site of interaction for food components and their biological activities. These mechanisms include (i) regulation of nutrient digestion and absorption (GP has been shown to inhibit enzymes such as α-amylase and α-glucosidase, protease, and lipase, which can help to reduce blood glucose and lipid levels, and to modulate the expression of intestinal transporters, which can also help to regulate nutrient absorption); (ii) modulation of gut hormone levels and satiety (GP stimulates GLP-1, PYY, CCK, ghrelin, and GIP release, which can help to regulate appetite and satiety); (iii) reinforcement of gut morphology (including the crypt-villi structures, which can improve nutrient absorption and protect against intestinal damage); (iv) protection of intestinal barrier integrity (through tight junctions and paracellular transport); (v) modulation of inflammation and oxidative stress triggered by NF-kB and Nrf2 signaling pathways; and (vi) impact on gut microbiota composition and functionality (leading to increased production of SCFAs and decreased production of LPS). The overall effect of GP within the gut environment reinforces the intestinal function as the first line of defense against multiple disorders, including those impacting cardiometabolic health. Future research on GP’s health-promoting properties should consider connections between the gut and other organs, including the gut-heart axis, gut-brain axis, gut-skin axis, and oral-gut axis. Further exploration of these connections, including more human studies, will solidify GP’s role as a cardiometabolic health-promoting ingredient and contribute to the prevention and management of cardiovascular diseases. Full article

This review article is built on the beneficial effects of Lactobacillus against different diseases, and a special focus has been made on its effects against neurological disorders, such as depression, multiple sclerosis, Alzheimer’s, and Parkinson’s disease. Probiotics are live microbes, which are found in fermented foods, beverages, and cultured milk and, when administered in an adequate dose, confer health benefits to the host. They are known as “health-friendly bacteria”, normally residing in the human gut and involved in maintaining homeostatic conditions. Imbalance in gut microbiota results in the pathophysiology of several diseases entailing the GIT tract, skin, immune system, inflammation, and gut–brain axis. Recently, the use of probiotics has gained tremendous interest, because of their profound effects on the management of these disease conditions. Recent findings suggest that probiotics enrichment in different human and mouse disease models showed promising beneficial effects and results in the amelioration of disease symptoms. Thus, this review focuses on the current probiotics-based products, different disease models, variable markers measured during trials, and evidence obtained from past studies on the use of probiotics in the prevention and treatment of different diseases, covering the skin to the central nervous system diseases. Full article