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ObjectiveTo explore the possible mechanism of the Yiqi Jiedu formula （YQ） in treating ischemic stroke （IS） from the perspective of the microbial-gut-brain axis （MGBA）. MethodRats were randomly divided into five groups， with six in each group， including sham surgery group， model group， and low， medium， and high dose YQ groups （1， 5， and 25 mg·kg-1）. Except for the sham surgery group， all other groups were established with a middle cerebral artery occlusion （MCAO） model using the thread occlusion method. The success of modeling was determined through neurobehavioral scoring， and the protective effect of YQ on IS was evaluated. Then， the changes in gut microbiota before and after MCAO modeling and YQ administration were compared using 16S rDNA sequencing technology， and the possible biological pathways related to the effect of this formula were analyzed. The expression of inflammatory factors such as interleukin-6 （IL-6）， interleukin-17A （IL-17A）， and interleukin-10 （IL-10） in serum was detected by enzyme-linked immunosorbent assay （ELISA）. Western blot was used to detect the expression of tight junction proteins ZO-1 and Occludin in brain and intestinal tissue， and hematoxylin-eosin staining （HE） was used to observe pathological changes in the cerebral cortex and colon， so as to validate the possible mechanism of action. ResultYQ significantly improved the neurobehavioral score of MCAO rats （P<0.01） and played a good regulatory role in intestinal microbial disorders caused by enriched pathogens and opportunistic pathogens during the acute phase. Among them， significantly changed microorganisms include Morgentia， Escherichia Shigella， Adlercreutzia， and Androbacter. Bioinformatics analysis found that these bacteria may be related to the regulation of inflammation in the brain. Compared with the blank group， the detection of inflammatory factors in the serum of IS model rats showed an increase in inflammatory factors IL-6 and IL-17A （P<0.01） and a decrease in the content of anti-inflammatory factor IL-10 （P<0.01）. Compared with the model group， the content of inflammatory factors IL-6 and IL-17A in the serum of the treatment group decreased （P<0.05）， and that of anti-inflammatory factor IL-10 increased （P<0.01）. The expression results of barrier proteins ZO-1 and Occludin in brain and intestinal tissue showed that the expression levels of both decreased in IS model rats （P<0.05）， while the expression levels of both increased in the treatment group （P<0.05）. ConclusionAcute cerebral ischemia can lead to an imbalance of intestinal microbiota and damage to the intestinal barrier， and it can increase intestinal permeability. YQ can regulate intestinal microbiota imbalance caused by ischemia， inhibit systemic inflammatory response， and improve the disruption of the gut-blood brain barrier， preventing secondary cascade damage to brain tissue caused by inflammation. The MGBA may be an important mechanism against the IS.
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Alzheimer's disease is a common central neurodegenerative disease， mainly manifested by cognitive impairment and non-cognitive neuropsychiatric symptoms that severely affect patients' daily life and behavioral functioning. The pathogenesis of Alzheimer's disease is still unclear， and the western medicine currently used to treat Alzheimer's disease is only symptomatic， with a single pathway， limited efficacy， and many side effects. In recent years， with the deepening of research on Alzheimer's disease， the study and application of traditional Chinese medicine （TCM） in the treatment of Alzheimer's disease have gradually increased. Several studies have shown that TCM and its effective components can exert anti-Alzheimer's disease effects by regulating molecular mechanisms such as pathological protein production and aggregation， oxidative stress， neuroinflammation， ferroptosis， mitochondrial dysfunction， neurogenesis and neurotransmission， and brain-gut axis. This paper summarized the research progress of TCM in the treatment of Alzheimer's disease in recent years， so as to provide a reference for further study of the specific mechanism of TCM in the prevention and treatment of Alzheimer's disease and the discovery of effective components of TCM.
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Recent research has shown a strong correlation between gut dysbiosis and Alzheimer’s disease (AD). The purpose of this review is to investigate the relationship between gut dysbiosis, immune system activation, and the onset of AD and to examine current breakthroughs in microbiota-targeted AD therapeutics. A review of scientific literature was conducted to assess the correlation between gut dysbiosis and AD and the various factors associated. Gut dysbiosis produces an increase in harmful substances, such as bacterial amyloids, which makes the gut barrier and blood-brain barrier more permeable. This leads to the stimulation of immunological responses and an increase in cytokines such as interleukin-1? (IL-1?). As a result, gut dysbiosis accelerates the progression of AD. The review highlights the connection between gut dysbiosis and AD and the potential for microbiota-targeted therapies in AD treatment.
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Disorders of the gut flora (GF) affect the level of 5-hydroxytryptamine (5-HT) in the brain of patients with generalized anxiety disorder (GAD) and influence the development of the disease. Most of the acupuncture points selected for GAD are based on the principles of local acupuncture points and acupuncture points following the distant channels of the meridians, regarding Baihui (DU 20), Fengchi (GB 20), and Yintang (GV 29) as the main acupuncture points, and the acupuncture points selected for the regulation of GF are Zhongwan (CV 12), Tianshu (ST 25), and Guanyuan (RN 4) and Zusanli (ST 36). Recently, many studies have been conducted on the mechanism of action of acupuncture in the treatment of GAD from the perspective of GF, but few have investigated the theoretical of acupuncture points used to prevent and treat GAD. This paper discusses the theoretical basis of acupuncture to regulate the "microbiota-gut-brain axis" (MGBA) for the prevention and treatment of GAD, and proposes the method of "regulating the internal organs and calming the mind and relieving anxiety" through analyzing the researches on the regulation of GF and GAD.
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Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children, which can be characterized by hyperactivity and(or)impulsivity, inattention, or a combination.The etiology and pathophysiological mechanism of ADHD have not been clarified yet.More and more studies have shown ADHD has intestinal flora disorder, which may affect the occurrence and development of ADHD through microbiome-gut-brain axis (MGBA). Treatment strategies targeting gut microbiota, including probiotics and dietary therapies, are considered to be a novel and effective method for the prevention or treatment of ADHD.This article reviews the changes of intestinal flora and the progress of diet and probiotics in ADHD children, in order to provide new ideas for treatment of ADHD children.
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OBJECTIVE@#To investigate whether gut microbiota disturbance after cardiopulmonary bypass (CPB) contributes to the development of perioperative neurocognitive disorders (PND).@*METHODS@#Fecal samples were collected from healthy individuals and patients with PND after CPB to prepare suspensions of fecal bacteria, which were transplanted into the colorectum of two groups of pseudo-germ-free adult male SD rats (group NP and group P, respectively), with the rats without transplantation as the control group (n=10). The feces of the rats were collected for macrogenomic sequencing analysis, and serum levels of IL-1β, IL-6 and TNF-α were measured with ELISA. The expression levels of GFAP and p-Tau protein in the hippocampus of the rats were detected using Western blotting, and the cognitive function changes of the rats were assessed with Morris water maze test.@*RESULTS@#In all the 3 groups, macrogenomic sequencing analysis showed clustering and clear partitions of the gut microbiota after the transplantation. The relative abundances of Klebsiella in the control group (P < 0.005), Akkermansia in group P (P < 0.005) and Bacteroides in group NP (P < 0.005) were significantly increased after the transplantation. Compared with those in the control group, the rats in group NP and group P showed significantly decreased serum levels of IL-1β, IL-6 and TNF-α and lowered expression levels of GFAP and p-Tau proteins (all P < 0.05). Escape platform crossings and swimming duration in the interest quadrant increased significantly in group NP (P < 0.05), but the increase was not statistically significant in group N. Compared with those in group P, the rats in group NP had significantly lower serum levels of IL-1β, IL-6 and TNF-α and protein expressions of GFAP and p-Tau (all P < 0.05) with better performance in water maze test (P < 0.05).@*CONCLUSION@#In patients receiving CPB, disturbances in gut mirobiota contributes to the development of PND possibly in relation with inflammatory response.
Subject(s)
Male , Animals , Rats , Rats, Sprague-Dawley , Cardiopulmonary Bypass , Gastrointestinal Microbiome , Interleukin-6 , Tumor Necrosis Factor-alpha , Neurocognitive DisordersABSTRACT
【Objective】 To investigate the effects of neuropathic pain induced by selective nerve injury (SNI) on intestinal microflora diversity in C57 mice. 【Methods】 36 C57 mice were randomly divided into SNI model group (n=18), sham-operation group (n=8), and control group (n=10). At day 0,1, 3, 7, and 14 after modeling, mechanical pain threshold and thermal pain sensitivity tests were carried out. At day 14 after modeling, colon content (fresh feces) from all the mice were collected for intestinal microflora diversity analysis. 【Results】 One day after modeling, the mechanical pain threshold in SNI group decreased significantly (more than 70%) due to nerve injury, and the thermal pain threshold decreased by 40%, while sham group and control group had no significant decrease. SNI group showed foot hyperalgesia, and the difference was statistically significant compared with sham group and control group (P<0.001). Compared with control group, sham-operation group had a transient decrease in thermal pain threshold on the first day after modeling (P=0.006), but there was no difference in pain threshold between the two groups on the third day after modeling. The α-diversity analysis showed that the abundance of Observed, Chao1, ACE and Simpson in SNI group was significantly lower than that in control group (P<0.05). That is, SNI group had flora disorder due to pain stimulation. Observed, Chao1, ACE, and Simpson were less abundant in sham group than in control group (P<0.05) and the change was between SNI group and control group. 【Conclusion】 Neuropathic pain induced by SNI model resulted in the decrease of mechanical pain threshold and thermal pain threshold, which leads to the reduction of intestinal flora diversity in C57 mice.
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Microbiota is the entire collection of microorganisms in a specific niche, such as the human gut. It impacts almost all organ systems and is related to disease resistance and susceptibility of the host. The microbiome refers to all of the genetic material within a microbiota. Microbiota is studied by means of sequencing specific genes or metagenomes; analyzing the species and their abundance and function; and determining the structure, diversity, evolutionary relationships, biological and medical significance, and their interactions with the environment of the microbiota. Human gut microbiota refers to that living in the human intestinal tract, including bacteria, fungi and viruses (bacteriophages). Current studies show that gut microbiota is closely related to human health, and its influence scope is far beyond the digestive system, but also involves the immune system, cardiovascular system, nervous system and other aspects. Substance addiction, a chronic recurrent brain disease, is characterized by persistent craving for addictive substances and forced drug use, which can cause changes in gut microbiota. We intend to discuss the relationship of gut microbiota with alcohol, cocaine, opioids, methamphetamine and other addictive substances, indicating that intervention in gut microbiota, which affects the structure and function of the brain, may become a new way to treat substance addiction.
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Glucagon-like peptide-1 (GLP-1) is a major hormone of incretin hormone and gut-brain axis, which is related to the control of energy homeostasis and the occurrence of obesity. In addition to suppressing appetite, GLP-1 has neuroprotective effects by acting on areas of the brain involved in stress response and mood regulation. Depression is a common mental disease, and GLP-1 is closely related to depression. This article reviews the role and mechanism of GLP-1 in depression.
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Methamphetamine (Meth) abuse can cause serious mental disorders, including anxiety and depression. The gut microbiota is a crucial contributor to maintaining host mental health. Here, we aim to investigate if microbiota participate in Meth-induced mental disorders, and the potential mechanisms involved. Here, 15 mg/kg Meth resulted in anxiety- and depression-like behaviors of mice successfully and suppressed the Sigma-1 receptor (SIGMAR1)/BDNF/TRKB pathway in the hippocampus. Meanwhile, Meth impaired gut homeostasis by arousing the Toll-like receptor 4 (TLR4)-related colonic inflammation, disturbing the gut microbiome and reducing the microbiota-derived short-chain fatty acids (SCFAs). Moreover, fecal microbiota from Meth-administrated mice mediated the colonic inflammation and reproduced anxiety- and depression-like behaviors in recipients. Further, SCFAs supplementation optimized Meth-induced microbial dysbiosis, ameliorated colonic inflammation, and repressed anxiety- and depression-like behaviors. Finally, Sigmar1 knockout (Sigmar1-/-) repressed the BDNF/TRKB pathway and produced similar behavioral phenotypes with Meth exposure, and eliminated the anti-anxiety and -depression effects of SCFAs. The activation of SIGMAR1 with fluvoxamine attenuated Meth-induced anxiety- and depression-like behaviors. Our findings indicated that gut microbiota-derived SCFAs could optimize gut homeostasis, and ameliorate Meth-induced mental disorders in a SIGMAR1-dependent manner. This study confirms the crucial role of microbiota in Meth-related mental disorders and provides a potential preemptive therapy.
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Depression is a mental disorder with high morbidity, disability and relapse rates. Ginkgo biloba extract (GBE), a traditional Chinese medicine, has a long history of clinical application in the treatment of cerebral and mental disorders, but the key mechanism remains incompletely understood. Here we showed that GEB exerted anti-depressant effect in mice through regulating gut microbial metabolism. GBE protected against unpredictable mild stress (UMS)-induced despair, anxiety-like and social avoidance behavior in mice without sufficient brain distribution. Fecal microbiome transplantation transmitted, while antibiotic cocktail abrogated the protective effect of GBE. Spatiotemporal bacterial profiling and metabolomics assay revealed a potential involvement of Parasutterella excrementihominis and the bile acid metabolite ursodeoxycholic acid (UDCA) in the effect of GBE. UDCA administration induced depression-like behavior in mice. Together, these findings suggest that GBE acts on gut microbiome-modulated bile acid metabolism to alleviate stress-induced depression.
Subject(s)
Humans , Mice , Animals , Depression/drug therapy , Gastrointestinal Microbiome , Plant Extracts , Ginkgo bilobaABSTRACT
A new study in Cell from Ivan de Araujo and colleagues reported that intestinal GLP-1 acts on an inter-organ sympathetic neural circuit that induces appetite suppression. This study revealed that GLP-1， secreted by ileal L cells， sensing by intestinal myenteric layer intestinofugal neurons activated a sympatho-gastro-spinal-reticular-hypothalamic pathway involved in appetite suppression， linking stomach distention to craniofacial programs for food rejection. These molecularly indentified， delimited enteric circuits may be targeted to ameliorate the abdominal bloating and loss of appetite typical of gastric motility disorders.
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The degeneration of monoaminergic system and the reduction of monoamine neurotransmitters(MNTs) are associated with the occurrence of a variety of neuropsychiatric diseases, becoming the key indicators for clinical diagnosis and treatment. Recent studies suggested gut microbiota could influence the occurrence, development, and treatment of neuropsychiatric diseases by directly or indirectly regulating the synthesis and metabolism of MNTs. Rich clinical experience has been accumulated in the amelioration and treatment of neuropsychiatric diseases by traditional Chinese medicines. The traditional oral administration method demonstrates obvious advantages in regulating gut microbiota. It provides a new idea for explaining the pharmacodynamic material basis and mechanism of traditional Chinese medicines in ameliorating neuropsychiatric disease by improving the levels of MNTs via gut microbiota regulation. Focusing on three common neuropsychiatric diseases including Alzheimer's disease, Parkinson's disease, and major depression, we summarized the pathways of gut microbiota in regulating the levels of MNTs and the paradigms of traditional Chinese medicines in ameliorating neuropsychiatric diseases via the "bacteria-gut-brain axis", aiming to provide ideas for the development of drugs and treatment schemes.
Subject(s)
Humans , Administration, Oral , Alzheimer Disease , Brain-Gut Axis , Gastrointestinal Microbiome , Neurotransmitter AgentsABSTRACT
Changes in the composition and ratio of the gut microbes may be associated with many diseases, including mild cognitive impairment (MCI). MCI includes amnestic mild cognitive impairment (aMCI) and non-amnestic mild cognitive impairment (non-aMCI). AMCI translates into Alzheimer's disease (AD) risk is higher, so aMCI may be the best stage for the prevention of AD in the future. Studies have shown that modulating the gut microbiota in patients with aMCI can improve their cognitive function.
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White matter injury in preterm infants is a unique form of brain injury.It is one of the most common cause of chronic neurological diseases such as cerebral palsy and various neurobehavioral disorders.Perinatal infection, inflammation and hypoxic ischemia are related to the pathophysiology of white matter injury in preterm infants.Signals released by the gut microbiota, such as microbial metabolites, can modulate inflammatory and immune responses characterized by microglial activation, and ultimately it affects the differentiation of premyelin oligodendrocytes and causes white matter injury in preterm infants.Recently more attention has been paid to the role of gut microbiota in the pathogenesis of white matter injury in preterm infants.This article reviews the progress of "microbiota-gut-brain axis" involved in the pathogenesis of white matter injury in preterm infants, so as to provide reference for further prevention and treatment of white matter injury.
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Depression is a common emotional mental disorder. Patients not only continuously showed depression, pessimism and apathy in mood, but also have gastrointestinal symptoms such as anorexia and constipation in body. Widely attention has been also received in the potential biological role of gut microbiota in the pathogenesis of depression. It plays an important role in the interaction between the intestine and the brain, not only affecting the intestinal barrier function, but also maintaining the homeostasis of host through the microbiota-gut-brain axis. In recent years, the traditional Chinese medicine (TCM) has the advantages of obvious therapeutic effects and few side effects when treating neuropsychiatric diseases, such as depression. The pharmacological mechanism of TCM exerting antidepressant effects by regulating the structure of gut microbiota, reducing displacement, and maintaining the normal function of gut microbiota has been also widely concerned. By investigating the relevant literature in recent years, this paper summarizes the antidepressant effect of TCM in different directions such as Chinese medicine monomer, single medicine and compound medicine. And this paper reviews the antidepressant effects and mechanisms of TCM at different levels, such as the correction of gut microbiota structure, the regulation of immunity, the transplantation of gut microbiota and the regulation of its metabolites. This paper will provide a basis for further explaining the mechanism of gut microbiota in depression and the mechanism of antidepressant effect of TCM.
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Under the guidance of the traditional Chinese medicine(TCM) theory of "Zangfu-organs of spleen and stomach" and the modern theory of "microbiota-gut-brain axis", this study explored the effects of Nardostachys jatamansi on the gut microbiota of rats with Parkinson's disease(PD). The 40 SD rats were randomly divided into the control group, PD model group, levodopa group, and Nardostachys jatamansi ethanol extract group. The PD model was established by subcutaneous injection of rotenone in the neck and back area. After 14 days of intragastric administration, the PD rats' behaviors were analyzed through open field test, inclined plane test, and pole test. After the behavioral tests, the striatum, colon, and colon contents of rats in each group were collected. Western blot was employed to detect the protein expression of tyrosine hydroxylase(TH) and α-synuclein(α-syn) in striatum and that of α-syn in colon. Enzyme linked immunosorbent assay(ELISA) was used to detect the levels of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), and nuclear factor-kappa B(NF-κB) in striatum and colon. High-throughput sequencing of 16 S rRNA gene was conducted to detect the differences in microbial diversity, abundance, differential phyla, and dominant bacteria of rats between groups. The results indicated that Nar. ethanol extract could relieve dyskinesia, reverse the increased levels of α-syn, TNF-α, IL-1β, and NF-κB in striatum, and improve the protein expression of TH in striatum of PD rats. The α diversity analysis indicated a significant decrease in diversity and abundance of gut microbiota in the PD model. The results of linear discriminant analysis effect size(LEfSe) of dominant bacteria indicated that Nardostachys jatamansi ethanol extract increased the relative abundance of Clotridiaceae, Lachnospiraceae, and Anaerostipes, and reversed the increased relative abundance of Proteobacteria, Gammaproteobacteria, Enterobacteriaceae, and Escherichia-Shigella in PD model group to exhibit the neuroprotective effect. In summary, the results indicated that Nar. ethanol extract exert the therapeutic effect on PD rats. Specifically, the extract may regulate gut microbiota, decrease the levels of proinflammatory cytokines, and reduce the protein aggregation of α-syn in the colon and striatum to alleviate intestinal inflammation and neuroinflammation. This study provides a basis for combining the theory of "Zangfu-organs of spleen and stomach" with the theory of "microbiota-gut-brain axis" to treat PD.
Subject(s)
Animals , Rats , Gastrointestinal Microbiome , NF-kappa B/metabolism , Nardostachys/metabolism , Parkinson Disease/drug therapy , Rats, Sprague-DawleyABSTRACT
Abstract Background: Postoperative cognitive dysfunction is widely recognized as severe postoperative central nervous dysfunction and has a significant impact on the 'patient's physical and mental health. Methods: Postoperative models of tibial fracture in aged rats were established, including the control group, model group, CCL11 protein injection group, and saline injection group. Morris water maze test was used to detect the behavioral characteristics of rats. Enzyme-Linked Immunosorbent Assay was used or determine the content of CCL11 and CXCL10. Immunofluorescence staining was used to detect the distribution of CD14+CD163+macro-phages in colon tissues and CD11b+CCR3+microglia cells in hippocampal tissues. Western blot analyzed NOX1 and STAT3 expression in hippocampus tissues. Results: Water maze test results confirmed severe cognitive impairment in CCL11 rats. The content of CCL11 and CXCL10 in the CCL11 group was much higher than that of the model group. The distribution of macrophage and microglia cells in the CCL11 model group was greater than that in the model group and the saline group. The expression of NOX1 and STAT3 in the CCL11 group was higher compared with the model group. Conclusion: Abnormal macrophage function and excessive CCL11 secretion were observed in the rats with lower limb fractures after surgery. Postoperative central inflammation in rats with lower limb fracture induced postoperative cognitive dysfunction through the gut-brain axis molecular mechanism.
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Os casos de transtorno de ansiedade têm apresentado crescimento considerável desde o início do século XX, onde a terapia medicamentosa oferecida, geralmente apresenta efeito sedativo, portanto, a busca por tratamentos adjuvantes para tratar quadros de ansiedade se fazem necessários. Estudos indicam que a modulação da microbiota intestinal pode estar relacionada à regulação neural dos indivíduos através de diversas vias, incluindo a aplicação de cepas probióticas e consumo de alimentos fermentados tradicionais como iogurte e kombucha, colaborando para a melhoria da qualidade de vida destes pacientes. Este projeto teve como objetivo buscar os metabólitos e neurotransmissores presentes no kombucha a fim de verificar seu potencial psicobióticos e comparar as aplicações e metabólitos produzidos por cepas probióticas existentes no mercado e em alimentos fermentados tradicionais que atuem no eixo intestino-cérebro. Foram realizadas pesquisas em bases de dados online, como Pubmed, Web of Science, Scielo, Scopus e Google Scholar no período entre 2002 e 2022 relacionados aos possíveis efeitos dos probióticos em condições de ansiedade, bem como como os mecanismos que envolvem o eixo cérebro-intestino, seja por meio de testes em humanos e em modelos animais. As espécies mais testadas quanto ao seu potencial probiótico e ação nos transtornos de ansiedade encontradas foram Lactobacillus paracasei, L. casei, L. rhamnosus, Bifidobacterium infanti e B. longum. Cada gênero demonstra um grau diferente na redução da ansiedade dos indivíduos. Os alimentos potencialmente probióticos, incluindo alimentos fermentados tradicionais, além de atuar como complemento à terapia em quadros de ansiedade, tem relevância no setor socioeconômico
Anxiety disorder cases have shown considerable growth since the beginning of the 20th century, where the drug therapy offered usually has a sedative effect. Therefore, the search for adjuvant treatments to treat anxiety disorders is necessary. Studies indicate that the modulation of the intestinal microbiota may be related to the neural regulation of individuals in several ways, including the application of probiotic strains and consumption of traditional fermented foods such as yogurt and kombucha, contributing to the improvement of the quality of life of these patients. This project aimed to identify and compare the psychobiotic effect in the gut-brain axis of the metabolites and neurotransmitters produced by kombucha and commercial probiotic strains. The research was carried out in online databases, such as Pubmed, Web of Science, Scielo, Scopus, and Google Scholar in the period between 2002 and 2022 related to the possible effects of probiotics in anxiety conditions as the mechanisms that involve the brain-gut axis either through tests in humans or animal models. The species most tested for their probiotic potential and action on anxiety disorders were Lactobacillus paracasei, L. casei, L. rhamnosus, Bifidobacterium infanti, and B. longum. Each genus demonstrates a different degree of reducing individuals' anxiety. Potentially probiotic foods, including traditional fermented foods, acting as a complement to therapy in cases of anxiety, have relevance in the socioeconomic sector
Subject(s)
Phobic Disorders/pathology , Kombucha Tea/analysis , Kombucha Tea/adverse effects , Serotonin/analogs & derivatives , Microbiota , Fermented Foods/adverse effects , Brain-Gut AxisABSTRACT
Resumo Esta revisão visa a conhecer e analisar os efeitos dos probióticos na depressão, ansiedade e estresse psicológico. Esses distúrbios estão entre as principais causas de incapacidades no mundo. As farmacoterapias convencionais costumam apresentar fraca resposta ou efeitos colaterais adversos. Estudos mais recentes têm demonstrado uma densa comunicação bidirecional chamada de eixo cérebro-intestino. Pesquisas estão evidenciando as relações entre alterações no microbioma entérico e distúrbios psiquiátricos, abrindo caminho para o surgimento de terapêuticas alternativas. Fez-se uma busca sistemática por ensaios clínicos randomizados duplo/triplo cego controlados por placebo no PubMed, Scopus e Lilacs. Para seleção dos estudos usaram-se as recomendações dos principais itens para relatar revisões sistemáticas e meta-análises (PRISMA). Nove artigos preencheram os critérios e foram analisados quanto aos efeitos na depressão, ansiedade, estresse psicológico e em biomarcadores. Sete encontraram resultados positivos em ao menos um dos itens. Conclui-se que o uso de probióticos para aliviar sintomas desses distúrbios é promissor, principalmente, por seu potencial efeito anti-inflamatório, mas são necessários ensaios clínicos randomizados duplo-cegos mais amplos e rigorosos para balizar tais conclusões.
Abstract This review aims to understand and analyse the effects of probiotics on depression, anxiety and psychological stress. These disorders are among the leading causes of disability worldwide. Conventional pharmacotherapies usually have a poor response or adverse side effects. In this context, recent studies have demonstrated a dense bi-directional communication named gut-brain axis. Evidences are demonstrating the relationship between disturbance in the enteric microbiome and psychiatric disorders, paving the way for the emergence of alternative therapies. A systematic search for randomized double/triple blind placebo-controlled clinical trials was performed in PubMed, Scopus and Lilacs. The studies selection followed the recommendations of the main items for report systematic reviews and meta-analyses (PRISMA). Nine articles met the criteria and were analysed for effects on depression, anxiety, psychological stress and biomarkers. Seven found positive results in at least one of the items. We concluded that the use of probiotics to alleviate depressive symptoms and anxiety is promising, mainly due to its potential anti-inflammatory effect, but additional and more rigorous double blind randomized clinical trials are necessary to endorse such conclusions.