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A randomized trial of probiotic supplementation in nurses to reduce stress and viral illness.
Slykerman, RF, Li, E
Scientific reports. 2022;12(1):14742
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Dynamic communication occurs between the gut microbiota and the central nervous system along multiple physiological pathways. Stress increases glucocorticoid production and activation of the hypothalamic–pituitary–adrenal axis, affecting immunological function and neuronal changes. The aim of this study was to investigate whether supplementation with the probiotic Lactobacillus rhamnosus HN001 could reduce symptoms of stress and anxiety and improve psychological wellbeing in nurses working during the COVID19 pandemic. This study was a large double-blind, placebo-controlled randomised trial of probiotic supplementation with two parallel arms and a ratio of allocation to probiotic or placebo of 1:1. Results showed that following the intervention, stress, anxiety, and psychological wellbeing were not significantly different between nurses supplemented with the probiotic and those who received the placebo. Furthermore, the average number of days per week that nurses reported symptoms of cold or flu-like illness did not significantly differ between the probiotic and placebo supplemented groups. Authors conclude that there weren’t significant differences in outcomes between the probiotic and placebo groups.
Abstract
Animal studies demonstrate how the gut microbiota influence psychological health and immunity to viral infections through their actions along multiple dynamic pathways in the body. Considerable interest exists in probiotics to reduce stress and illness symptoms through beneficial effects in the gut, but translating pre-clinical evidence from animal models into humans remains challenging. We conducted a large trial in nurses working during the 2020 COVID19 pandemic year to establish whether daily ingestion of the probiotic Lactobacillus rhamnosus HN001 reduced perceived stress and the number of days participants reported symptoms of a viral illness. Our results showed no significant difference in perceived stress or the average number of illness days between probiotic supplemented nurses and the placebo group. Stress and viral illness symptoms reduced during the study for all participants, a trajectory likely influenced by societal-level factors. The powerful effect of a well-managed public health response to the COVID19 pandemic and the elimination of COVID19 from the community in 2020 may have altered the trajectory of stress levels and reduced circulating viral infections making it difficult to detect any effect of probiotic supplementation. Our study highlights the challenge in controlling environmental factors in human trials.
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Updated Review and Meta-Analysis of Probiotics for the Treatment of Clinical Depression: Adjunctive vs. Stand-Alone Treatment.
Nikolova, VL, Cleare, AJ, Young, AH, Stone, JM
Journal of clinical medicine. 2021;10(4)
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Major depressive disorder is a common, complex, and heterogeneous illness that is characterized by persistent low mood and anhedonia, and a combination of sleep disturbances, changes in appetite, feelings of worthlessness or guilt, poor concentration, and suicidal ideation. The aim of this study was to identify and evaluate all current evidence from randomised controlled trials on the efficacy of probiotics in reducing depressive symptoms among people with clinical depression. This study is a review and meta-analysis of randomised controlled trials which included seven studies for qualitative and quantitative analysis. Results demonstrate that probiotics significantly reduce depressive symptoms after eight weeks of use, but only when used in addition to an approved antidepressant. Authors conclude that their findings support the clinical use of probiotics in depressed populations and provides an insight into the mode of administration more likely to yield antidepressant effects.
Abstract
Recent years have seen a rapid increase in the use of gut microbiota-targeting interventions, such as probiotics, for the treatment of psychiatric disorders. The objective of this update review was to evaluate all randomised controlled clinical trial evidence on the efficacy of probiotics for clinical depression. Cochrane guidelines for updated reviews were followed. By searching PubMed and Web of Science databases, we identified 546 new records since our previous review. A total of seven studies met selection criteria, capturing 404 people with depression. A random effects meta-analysis using treatment type (stand-alone vs. adjunctive) as subgroup was performed. The results demonstrated that probiotics are effective in reducing depressive symptoms when administered in addition to antidepressants (SMD = 0.83, 95%CI 0.49-1.17), however, they do not seem to offer significant benefits when used as stand-alone treatment (SMD = -0.02, 95%CI -0.34-0.30). Potential mechanisms of action may be via increases in brain-derived neurotrophic factor (BDNF) and decreases in C-reactive protein (CRP), although limited evidence is available at present. This review offers stronger evidence to support the clinical use of probiotics in depressed populations and provides an insight into the mode of administration more likely to yield antidepressant effects.
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Exploring the Role and Potential of Probiotics in the Field of Mental Health: Major Depressive Disorder.
Johnson, D, Thurairajasingam, S, Letchumanan, V, Chan, KG, Lee, LH
Nutrients. 2021;13(5)
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A bi-directional communication between the brain and the microbiome of the gut may exist, known as the microbiome-gut-brain axis (MGBA). The role of this and the use of probiotics in relation to many psychiatric and neurological disorders is being increasingly researched. This review aimed to summarise the research on the use of probiotics for the treatment of mental health disorders and major depressive disorder (MDD). Probiotics and their use were summarised concluding that they have a diverse range of health benefits due to their anti-inflammatory, antipathogenic and antimicrobial actions. Imbalances in the four major phyla of gut bacteria; Bacteroidetes, Firmicutes, Proteobacteria and Actinobacteria may have a major role in the development of MDD. Probiotics may have several mechanisms through which they benefit MDD and decreased inflammation in the brain, increased production of chemicals involved in brain signalling and decreased stress hormones, were all implicated. It was concluded that probiotics have mental health benefits, however gaps in the evidence from studies needs to be addressed. This study could be used by healthcare professionals to understand the role of probiotics in the treatment of mental health disorders and in particular MDD.
Abstract
The field of probiotic has been exponentially expanding over the recent decades with a more therapeutic-centered research. Probiotics mediated microbiota modulation within the microbiota-gut-brain axis (MGBA) have been proven to be beneficial in various health domains through pre-clinical and clinical studies. In the context of mental health, although probiotic research is still in its infancy stage, the promising role and potential of probiotics in various mental disorders demonstrated via in-vivo and in-vitro studies have laid a strong foundation for translating preclinical models to humans. The exploration of the therapeutic role and potential of probiotics in major depressive disorder (MDD) is an extremely noteworthy field of research. The possible etio-pathological mechanisms of depression involving inflammation, neurotransmitters, the hypothalamic-pituitary-adrenal (HPA) axis and epigenetic mechanisms potentially benefit from probiotic intervention. Probiotics, both as an adjunct to antidepressants or a stand-alone intervention, have a beneficial role and potential in mitigating anti-depressive effects, and confers some advantages compared to conventional treatments of depression using anti-depressants.
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Effectiveness of Probiotic, Prebiotic, and Synbiotic Supplementation to Improve Perinatal Mental Health in Mothers: A Systematic Review and Meta-Analysis.
Desai, V, Kozyrskyj, AL, Lau, S, Sanni, O, Dennett, L, Walter, J, Ospina, MB
Frontiers in psychiatry. 2021;12:622181
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Maternal mental health problems in the perinatal period are a global public health challenge. As many as one in five women develop depression and/or anxiety in the postpartum period, making them the most common complications of pregnancy and delivery. The aim of this study was to evaluate the evidence on the administration of prebiotic, probiotic, and/or synbiotic supplements during pregnancy to reduce the risk of mental health problems in the perinatal period. This study is a systemic review and meta-analysis of four studies of which three where included in the qualitative and quantitative synthesis. Results indicate limited evidence about the effectiveness of probiotics administered during pregnancy to reduce the risk of maternal mental health disorders and highlighted the lack of evidence on prebiotics and synbiotics supplementation to inform their use for similar purposes. Authors conclude that there is the need for future trials targeting microbiota interventions that test probiotic/prebiotic/synbiotic interventions that redress specific dysbioses in pregnancy gut microbiota that arise from poor mental health.
Abstract
Introduction: There is an emerging interest in modulating the gut microbiota to target the gut-brain axis and improve maternal mental health in the perinatal period. This systematic review evaluated the effectiveness of prebiotics, probiotics, and synbiotics supplementation during pregnancy to reduce the risk of maternal mental health problems in the perinatal period. Methods: Electronic biomedical databases and clinical trial registries were searched from database inception through August 2020 to identify randomized controlled clinical trials (RCTs) evaluating the effect of probiotic, prebiotic, or synbiotic supplements administered to women during pregnancy on measures of perinatal depression, anxiety, and other mental health outcomes. Study selection, risk of bias appraisal, and data extraction were independently performed by two reviewers. Pooled mean differences (MD) and odds ratios (pOR) with 95% confidence intervals (CI) were calculated in random-effects meta-analyses for the outcomes of interest in the review. Results: From 3,868 studies identified through the search strategy, three RCTs of low risk of bias involving 713 participants were included, all three testing probiotics. There were no differences between probiotics and control groups in the mean depression scores (MD -0.46; 95% CI -2.16, 1.25) at end of follow-up. Although statistical significance was not achieved, probiotics showed an advantage in the proportion of participants scoring below an established cut-off for depression (pOR 0.68; 95% CI 0.43, 1.07). Compared to placebo, probiotics in pregnancy reduced anxiety symptoms (MD -0.99; 95% CI -1.80, -0.18); however, this advantage was not translated in a reduction in the proportion of participants scoring above an established cut-off for anxiety (pOR 0.65; 95% CI 0.23, 1.85). There were no differences between probiotics and control groups in global mental health scores at end of follow-up (MD 1.09; 95% CI -2.04, 4.22). Conclusion: There is limited but promising evidence about the effectiveness of probiotics during pregnancy to reduce anxiety symptoms and reduce the proportion of women scoring ABOVE a cut-off depression score. There is a lack of RCT evidence supporting prebiotics and synbiotics supplementation for similar purposes in the perinatal period. More research is needed before prebiotics, probiotics, and synbiotics are recommended to support maternal mental health and well-being in the perinatal period. Systematic Review Registration: PROSPERO, CRD42019137158.
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Effects of Probiotics on Anxiety, Stress, Mood and Fitness of Badminton Players.
Salleh, RM, Kuan, G, Aziz, MNA, Rahim, MRA, Rahayu, T, Sulaiman, S, Kusuma, DWY, Adikari, AMGCP, Razam, MSM, Radhakrishnan, AK, et al
Nutrients. 2021;13(6)
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Exercise has been shown to improve fitness, wellbeing, and health. However, strenuous exercise may be detrimental physiologically, as well as affecting psychological health. The aim of this study was to determine the effects of daily probiotic supplementation on anxiety, stress, mood and fitness levels among competitive badminton players. This study was a randomised, placebo-controlled study. Recruited participants (n=30) were randomly divided into the probiotic group and the control group. The participants were given treatments for six weeks without altering the training schedule of the athletes. Results showed that stress and anxiety in badminton players could be alleviated with the daily consumption of probiotics for six weeks. Additionally, probiotics supplementation increased aerobic capacity. Authors conclude that probiotic supplements could be beneficial for athletes to enhance their mental state and physical performance. Thus, probiotic supplementation that may influence the regulation of pathways (neuro-endocrine) and mechanism of action in response to physical and psychological stressors encountered by badminton players should further studied.
Abstract
BACKGROUND Reports of probiotic consumption on athletes' performance are debatable due to their equivocal results. There is a need for more evidence on the effects of probiotic intake on psychological state and fitness level. Thus, this study determined the effects of daily probiotic consumption on competitive anxiety, perceived stress and mood among university badminton players, besides their fitness like aerobic capacity, strength, speed, leg power and agility. METHODS Thirty university badminton players aged from 19 to 22 years old were randomly divided equally into two groups, where the probiotic group (PG; n = 15) received a drink that contained Lactobacillus casei Shirota (3 × 1010 CFU) and placebo group (CG; n = 15) a placebo drink for six weeks. Anxiety, stress and mood levels were determined using the CSAI-2R, PSS and BRUMS questionnaires, respectively. Fitness levels were measured using by subjecting the players to 20-m shuttle runs (aerobic capacity), handgrips (muscular strength), vertical jumps (leg power), 40-m dash (speed) and T-test (agility). The Student's t-test (p < 0.05) was used to determine the differences between PG and CG players. RESULTS After six weeks, the anxiety and stress levels of PG players significantly decreased by 16% (p < 0.001) and 20% (p < 0.001), respectively, but there were no significant changes detected in CG players. Supplementation of probiotics also improved aerobic capacity in PG players by 5.9% (p < 0.001) but did not influence the speed, strength, leg power and agility. CONCLUSIONS Probiotics supplementation showed improved aerobic capacity and relieve anxiety and stress. However, further studies need to be carried out to determine the mechanisms through which probiotic intake produces these effects.
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Current Perspectives on Gut Microbiome Dysbiosis and Depression.
Capuco, A, Urits, I, Hasoon, J, Chun, R, Gerald, B, Wang, JK, Kassem, H, Ngo, AL, Abd-Elsayed, A, Simopoulos, T, et al
Advances in therapy. 2020;37(4):1328-1346
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The gut microbiome has been implicated in several neurological disorders; however exact mechanisms are still not fully understood. This review of recent studies, aimed to investigate the relationship between an imbalanced gut microbiome and depression. The authors first looked at the epidemiology of disease, concluding that significant burden needs to be assessed through improved preventative measures. This will depend upon the correct identification of risk factors, and the study focused on the role of the gut microbiome in this through animal and human studies. Imbalances in inflammation through altered gut microbiota, depleted biodiversity and stress induced microbiome changes were all implicated in the development of depression. It was concluded that studies on the role of microbiota in depression remain promising but are small and follow many different methodologies. This study could be used by healthcare professionals to better understand the role of gut microbiota in the development of depression and that ensuring a healthy gut may improve symptoms.
Abstract
The human gut microbiome partakes in a bidirectional communication pathway with the central nervous system (CNS), named the microbiota-gut-brain axis. The microbiota-gut-brain axis is believed to modulate various central processes through the vagus nerve as well as production of microbial metabolites and immune mediators which trigger changes in neurotransmission, neuroinflammation, and behavior. Little is understood about the utilization of microbiome manipulation to treat disease. Though studies exploring the role of the microbiome in various disease processes have shown promise, mechanisms remain unclear and evidence-based treatments for most illnesses have not yet been developed. The animal studies reviewed here offer an excellent array of basic science research that continues to clarify mechanisms by which the microbiome may affect mental health. More evidence is needed, particularly as it relates to translating this work to human subjects. The studies presented in this paper largely demonstrate encouraging results in the treatment of depression. Limitations include small sample sizes and heterogeneous methodology. The exact mechanism by which the gut microbiota causes or alters neuropsychiatric disease states is not fully understood. In this review, we focus on recent studies investigating the relationship between gut microbiome dysbiosis and the pathogenesis of depression. This article is based on previously conducted studies and does not contain any studies with human participants or animals performed by any of the authors.
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Mental Disorders Linked to Crosstalk between The Gut Microbiome and The Brain.
Choi, TY, Choi, YP, Koo, JW
Experimental neurobiology. 2020;29(6):403-416
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The gut microbiome may have a role in regular brain function and mental health and this review paper aimed to determine the mechanisms through which this may be possible. There are several mental health disorders that may be affected by the gut microbiome, major depressive disorder (MDD), anxiety disorder, autism spectrum disorder (ASD), Alzheimer’s disease (AD), and addiction. It appears that there is a correlation between a disordered gut microbiome (known as dysbiosis) and MDD, ASD and addiction. Anxiety symptoms in healthy individuals and cognitive deficits in individuals with AD have reportedly been improved with probiotics. How the gut microbiome communicates with the brain was also discussed with the enteric nervous system, vagus nerve, spinal chord, immune system and brain signalling molecules all being implicated as possible routes. Finally, the paper discussed the use of probiotics for the prevention or treatment of mental disorders, with Bifidobacteria, Lactobacillus and specifically L. reuteri, L. plantarum and L. helveticus all shown in animal models to improve aspects associated with mental disorders. Amongst the human research B. longum has been shown to relieve stress and increase cognitive function in healthy individuals. It was concluded that studies have elucidated a relationship between the gut microbiome and mental health through various routes of communication. Research should focus on how gut microbiome changes are involved in mental illness. This study could be used by healthcare professionals to further knowledge on the potential relationship between the gut microbiome and mental health.
Abstract
Often called the second brain, the gut communicates extensively with the brain and vice versa. The conversation between these two organs affects a variety of physiological mechanisms that are associated with our mental health. Over the past decade, a growing body of evidence has suggested that the gut microbiome builds a unique ecosystem inside the gastrointestinal tract to maintain the homeostasis and that compositional changes in the gut microbiome are highly correlated with several mental disorders. There are ongoing efforts to treat or prevent mental disorders by regulating the gut microbiome using probiotics. These attempts are based on the seminal findings that probiotics can control the gut microbiome and affect mental conditions. However, some issues have yet to be conclusively addressed, especially the causality between the gut microbiome and mental disorders. In this review, we focus on the mechanisms by which the gut microbiome affects mental health and diseases. Furthermore, we discuss the potential use of probiotics as therapeutic agents for psychiatric disorders.
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Bacterial Metabolites of Human Gut Microbiota Correlating with Depression.
Averina, OV, Zorkina, YA, Yunes, RA, Kovtun, AS, Ushakova, VM, Morozova, AY, Kostyuk, GP, Danilenko, VN, Chekhonin, VP
International journal of molecular sciences. 2020;21(23)
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Depression is multifactorial disease and it is the most common type of psychiatric disorder. Literature indicates that there are significant differences between the gut microbiota (GM) of patients with depression and healthy controls. The aim of this review was to examine (a) various low-molecular compounds as potential biomarkers of depression in correlation with the metabolism of the GM, and (b) ways to correct the microbiota imbalance. Results show that: - the use of the GM biomarkers, reflecting the neuromodulatory [the process by which nervous activity is regulated through classes of neurotransmitters], immunomodulatory [the process by which the body’s immune system is altered] and antioxidant statuses of the host organism, in the analysis of metagenomic [the study of a collection of genetic material (genomes) from a mixed community of organisms] data from patients with neuropsychiatric diseases, is gaining currency. - diet remains one of the most effective measures that can be taken to restore the microbial balance in the gut and alleviate the symptoms of depression. - a healthy diet during the depression therapy, along with the application of probiotics and psychobiotics, may potentially improve the course of the disease and contribute to the progress of treatment. Authors conclude that further progress in the practical understanding of the role of the GM in depression will greatly depend on correct planning of future metagenomic studies.
Abstract
Depression is a global threat to mental health that affects around 264 million people worldwide. Despite the considerable evolution in our understanding of the pathophysiology of depression, no reliable biomarkers that have contributed to objective diagnoses and clinical therapy currently exist. The discovery of the microbiota-gut-brain axis induced scientists to study the role of gut microbiota (GM) in the pathogenesis of depression. Over the last decade, many of studies were conducted in this field. The productions of metabolites and compounds with neuroactive and immunomodulatory properties among mechanisms such as the mediating effects of the GM on the brain, have been identified. This comprehensive review was focused on low molecular weight compounds implicated in depression as potential products of the GM. The other possible mechanisms of GM involvement in depression were presented, as well as changes in the composition of the microbiota of patients with depression. In conclusion, the therapeutic potential of functional foods and psychobiotics in relieving depression were considered. The described biomarkers associated with GM could potentially enhance the diagnostic criteria for depressive disorders in clinical practice and represent a potential future diagnostic tool based on metagenomic technologies for assessing the development of depressive disorders.
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Recognizing Depression from the Microbiota⁻Gut⁻Brain Axis.
Liang, S, Wu, X, Hu, X, Wang, T, Jin, F
International journal of molecular sciences. 2018;19(6)
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Emerging research indicates that major depression is not just a mental disorder but also a systemic disease. In depression, the brain-gut axis, the bidirectional pathway that connects the brain and gut, is thought to be disturbed. This disruption is hypothesised to be a major pathological basis of depression. The aim of this paper is to explore this hypothesis by reviewing the current literature. According to the current literature, the authors found research stating the gut microbiota of depressed patients is significantly different from that of healthy controls. Additionally, disturbances or abnormalities in the gut can influence the susceptibility of onset of depression, while restoration of the gut will alleviate depression. Based on these findings, the authors conclude depression is closely related with the condition of the brain-gut axis, and that restoring the normal condition of gut microbiota may aid in the therapy of depression. The authors expect therapies that target gut microbiota will play an important role in the treatment and prevention of depression in the future.
Abstract
Major depression is one of the leading causes of disability, morbidity, and mortality worldwide. The brain⁻gut axis functions are disturbed, revealed by a dysfunction of the brain, immune system, endocrine system, and gut. Traditional depression treatments all target the brain, with different drugs and/or psychotherapy. Unfortunately, most of the patients have never received any treatment. Studies indicate that gut microbiota could be a direct cause for the disorder. Abnormal microbiota and the microbiota⁻gut⁻brain dysfunction may cause mental disorders, while correcting these disturbance could alleviate depression. Nowadays, the gut microbiota modulation has become a hot topic in treatment research of mental disorders. Depression is closely related with the health condition of the brain⁻gut axis, and maintaining/restoring the normal condition of gut microbiota helps in the prevention/therapy of mental disorders.