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Lactobacillus rhamnosus CNCM I-3690 decreases subjective academic stress in healthy adults: a randomized placebo-controlled trial.
Wauters, L, Van Oudenhove, L, Accarie, A, Geboers, K, Geysen, H, Toth, J, Luypaerts, A, Verbeke, K, Smokvina, T, Raes, J, et al
Gut microbes. 2022;14(1):2031695
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Previous research has shown a bidirectional relationship between the gut and psychological stress, which could be mediated by intestinal permeability followed by an immune and inflammatory response. However, the exact mechanisms of this relationship are yet to be elucidated. This randomised, double-blind, placebo-controlled trial evaluated the beneficial effects of Lactobacillus rhamnosus CNCM I-3690 on intestinal permeability and stress markers during a public speech in healthy students. Participants consumed either milk containing Lactobacillus rhamnosus CNCM I-3690 or acidified milk twice daily for four weeks to assess subjective and objective stress markers and markers of intestinal permeability. Lactobacillus rhamnosus CNCM I-3690 reduced the stress-induced hyperpermeability to mannitol and subjective stress markers (State-Trait Anxiety Inventory/ STAI). A subgroup of healthy students with stress-induced cortisol >P90 of baseline showed a reduction in perceived stress score following Lactobacillus rhamnosus CNCM I-3690 intervention. To evaluate the additional effects of Lactobacillus rhamnosus CNCM I-3690 on stress and gut health, further robust studies are needed. Healthcare professionals can use the findings of this study to understand the anxiolytic effects of Lactobacillus rhamnosus CNCM I-3690.
Abstract
Psychological stress negatively affects the intestinal barrier function in animals and humans. We aimed to study the effect of Lactobacillus rhamnosus CNCM I-3690 on intestinal permeability and stress-markers during public speech. Healthy students were randomized to L. rhamnosus-containing (test) or acidified (placebo) milk consumed twice daily for 4 weeks, with 46 subjects per treatment group. Small intestinal permeability was quantified by a 2 h urinary lactulose-mannitol ratio (LMR, primary outcome), fractional excretion of lactulose (FEL) and mannitol (FEM). Salivary cortisol, State-Trait Anxiety Inventory (STAI) and Perceived Stress scores (PSS) were collected. No between-treatment differences were found for LMR (p = .71), FEL or FEM. Within-treatment analyses showed similar LMR and FEL but a stress-induced increase of FEM with the placebo (p < .05) but not test product. Despite a similar increase in salivary cortisol, the stress-induced increase in STAI was significantly lower with the test product vs. placebo (p = .01). Moreover, a stress-preventative effect of the probiotic was found for PSS and more pronounced in subjects with high stress-induced cortisol (p = .01). While increased FEM was mediated by salivary cortisol levels, the effect of the test product on subjective stress was not mediated by changes in FEM. No serious adverse events occurred. In conclusion, we demonstrated that L. rhamnosus CNCM I-3690 prevented stress-induced hyperpermeability to mannitol. Subjective but not objective stress-markers were reduced with L. rhamnosus vs. placebo, suggesting anxiolytic effects, which were independent of barrier stabilization and attractive for the reduction of stress in both health and disease. Clinicaltrials.gov, number NCT03408691.
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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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Using psychoneuroimmunity against COVID-19.
Kim, SW, Su, KP
Brain, behavior, and immunity. 2020;87:4-5
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This viewpoint article raises awareness of the threat of COVID-19 poses to psychiatric patients who are in mental health hospitals. Those patients appear to have a much elevated mortality rate and are potentially more vulnerable to the effects of panic/anxiety due to the pandemic. Their lifestyle choices, influenced by fears about the virus, may also have a negative effect on their immunity. The article also raises the issue of the effects the pandemic and associated changes to day-to-day life can have on the mental and general health of the rest of the population, and in particular to mental health professionals, whose ability to care for their psychiatric patients may be impaired. The authors also briefly discuss the psychological and immunological mechanisms that connect our mental state to the ability of our immune system to fight infections, and the impact of our lifestyles and environments. To summarise they state that infected patients, uninfected quarantined individuals and medical professionals all require mental health supporting strategies, and that epidemiological studies of potential long-term psychiatric consequences are essential.
Abstract
The worldwide outbreak of coronavirus disease 2019 (COVID-19) raises concerns of widespread panic and anxiety in individuals subjected to the real or perceived threat of the virus. Compared to general populations, patients who are institutionalized in a closed unit are also very vulnerable to COVID-19 infection and complications. This crisis touched on difficult issues of not only psychiatric care and ethics, but also psychological impacts to psychiatric care givers. In this Viewpoint, we address both physical and biopsychosocial aspects of this infection, as well as the psychoneuroimmunity of preventive strategies of healthy lifestyle, regular exercise, balanced nutrition, quality sleep and a strong connection with people. Social distancing and wearing masks might help us from pathogen exposure, yet such these measures also prevent us from expressing compassion and friendliness. Therefore, all forms of psychological support should be routinely implemented not only to consider psychological resilience but also to enhance psychoneuroimmunity against COVID-19.
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A Large Randomized Trial: Effects of Mindfulness-Based Stress Reduction (MBSR) for Breast Cancer (BC) Survivors on Salivary Cortisol and IL-6.
Lengacher, CA, Reich, RR, Paterson, CL, Shelton, M, Shivers, S, Ramesar, S, Pleasant, ML, Budhrani-Shani, P, Groer, M, Post-White, J, et al
Biological research for nursing. 2019;21(1):39-49
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Breast cancer survivors (BCS) often experience physiological and psychological stressors related to their diagnosis and treatment, and a disruption of cortisol function can affect cancer risk and progression. Increased levels of the stress hormone cortisol and interleukin-6 (IL-6), a pro-inflammatory immune mediator, have been associated with acute and chronic stress levels. Mindfulness-Based Stress Reduction (MBSR) is a clinical stress-reducing program, which has been found to decrease psychological and physical symptoms associated with stress. The purpose of this randomised study, involving 299 BCS, was to evaluate the efficacy of MBSR in reducing cortisol and IL-6 levels, compared to a usual-care control treatment. Statistically significant reductions in cortisol levels were seen after the delivery of the MBSR program at both time points (week 1 and 6), and at week 6 only for IL-6. There was no significant difference in change in cortisol or IL6 levels over time between the MBSR and the usual-care groups. An association was observed between levels of IL-6 and psychological and physical symptoms and quality of life, but not for cortisol. The authors conclude that MBSR can alleviate the stress response in the short term for breast cancer survivors.
Abstract
Breast cancer survivors (BCS) often experience psychological and physiological symptoms after cancer treatment. Mindfulness-based stress reduction (MBSR), a complementary and alternative therapy, has reduced subjective measures of stress, anxiety, and fatigue among BCS. Little is known, however, about how MBSR affects objective markers of stress, specifically the stress hormone cortisol and the pro-inflammatory cytokine interleukin-6 (IL-6). In the present study, BCS ( N = 322) were randomly assigned to a 6-week MBSR program for BC or usual-care control. Measurements of cortisol, IL-6, symptoms, and quality of life were obtained at orientation and 6 weeks. Cortisol and IL-6 were also measured prior to and after the MBSR(BC) class Weeks 1 and 6. The mean age of participants was 56.6 years and 69.4% were White non-Hispanic. Most had Stage I (33.8%) or II (35.7%) BC, and 35.7% had received chemotherapy and radiation. Cortisol levels were reduced immediately following MBSR(BC) class compared to before the class Weeks 1 and 6 (Wilcoxon-signed rank test; p < .01, d = .52-.56). IL-6 was significantly reduced from pre- to postclass at Week 6 (Wilcoxon-signed rank test; p < .01, d = .21). No differences were observed between the MBSR(BC) and control groups from baseline to Week 6 using linear mixed models. Significant relationships with small effect sizes were observed between IL-6 and both symptoms and quality of life in both groups. Results support the use of MBSR(BC) to reduce salivary cortisol and IL-6 levels in the short term in BCS.
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Fecal metagenomic profiles in subgroups of patients with myalgic encephalomyelitis/chronic fatigue syndrome.
Nagy-Szakal, D, Williams, BL, Mishra, N, Che, X, Lee, B, Bateman, L, Klimas, NG, Komaroff, AL, Levine, S, Montoya, JG, et al
Microbiome. 2017;5(1):44
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Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by unexplained persistent fatigue, cognitive dysfunction, sleep disturbances, orthostatic intolerance, fever, swollen lymph glands and irritable bowel syndrome (IBS). It is associated with gut bacterial dysbiosis, systemic inflammation and both gastro intestinal (GI) and neurological disturbances. The extent to which the gastrointestinal microbiome and peripheral inflammation are associated with ME/CFS remains unclear. This experiment looked at fecal bacterial samples and metabolic pathway markers in 50 ME/CFS patients and 50 healthy controls. In ME/CFS subgroups, measures of symptom severity including pain, fatigue, and reduced motivation were correlated with the amounts and types of gut bacteria and certain metabolic pathways. Future prospective studies should consider more detailed exploration of IBS subtypes, associated GI symptoms, and their relationship to ME/CFS dysbiosis. This may enable more accurate diagnosis and the development of specific therapeutic strategies.
Abstract
BACKGROUND Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by unexplained persistent fatigue, commonly accompanied by cognitive dysfunction, sleeping disturbances, orthostatic intolerance, fever, lymphadenopathy, and irritable bowel syndrome (IBS). The extent to which the gastrointestinal microbiome and peripheral inflammation are associated with ME/CFS remains unclear. We pursued rigorous clinical characterization, fecal bacterial metagenomics, and plasma immune molecule analyses in 50 ME/CFS patients and 50 healthy controls frequency-matched for age, sex, race/ethnicity, geographic site, and season of sampling. RESULTS Topological analysis revealed associations between IBS co-morbidity, body mass index, fecal bacterial composition, and bacterial metabolic pathways but not plasma immune molecules. IBS co-morbidity was the strongest driving factor in the separation of topological networks based on bacterial profiles and metabolic pathways. Predictive selection models based on bacterial profiles supported findings from topological analyses indicating that ME/CFS subgroups, defined by IBS status, could be distinguished from control subjects with high predictive accuracy. Bacterial taxa predictive of ME/CFS patients with IBS were distinct from taxa associated with ME/CFS patients without IBS. Increased abundance of unclassified Alistipes and decreased Faecalibacterium emerged as the top biomarkers of ME/CFS with IBS; while increased unclassified Bacteroides abundance and decreased Bacteroides vulgatus were the top biomarkers of ME/CFS without IBS. Despite findings of differences in bacterial taxa and metabolic pathways defining ME/CFS subgroups, decreased metabolic pathways associated with unsaturated fatty acid biosynthesis and increased atrazine degradation pathways were independent of IBS co-morbidity. Increased vitamin B6 biosynthesis/salvage and pyrimidine ribonucleoside degradation were the top metabolic pathways in ME/CFS without IBS as well as in the total ME/CFS cohort. In ME/CFS subgroups, symptom severity measures including pain, fatigue, and reduced motivation were correlated with the abundance of distinct bacterial taxa and metabolic pathways. CONCLUSIONS Independent of IBS, ME/CFS is associated with dysbiosis and distinct bacterial metabolic disturbances that may influence disease severity. However, our findings indicate that dysbiotic features that are uniquely ME/CFS-associated may be masked by disturbances arising from the high prevalence of IBS co-morbidity in ME/CFS. These insights may enable more accurate diagnosis and lead to insights that inform the development of specific therapeutic strategies in ME/CFS subgroups.