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Effects of Lactococcus lactis subsp. cremoris YRC3780 daily intake on the HPA axis response to acute psychological stress in healthy Japanese men.
Matsuura, N, Motoshima, H, Uchida, K, Yamanaka, Y
European journal of clinical nutrition. 2022;76(4):574-580
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Plain language summary
The hypothalamic-pituitary-adrenal (HPA) axis is involved in the stress response and is linked to the microbiome through a number of possible mechanisms, including immune-related ones. Lactococcus lactis subsp. cremoris YRC3780 (YRC3780), a probiotic isolated from kefir, has been shown to have beneficial immune-modulatory properties. The aim of this double-blind, placebo-controlled trial, which included 27 healthy young men, was to assess sleep quality, mental health, HPA axis activity (salivary cortisol) and response to an acute stress test during/after 8 weeks of supplementation with YRC3780. At 8 weeks, salivary morning cortisol levels were significantly reduced in the probiotic compared to the placebo group. The effect on the stress test depended on whether or not participants were considered “cortisol-responders” or not. Improvements in sleep quality were seen at 6 weeks (but not at any other time points) in 1 out of 2 sleep questionnaires in the YRC3780 group, whilst no significant differences were observed in actigraphy-measured sleep efficiency. There were no differences in mood between groups, but significant improvements in general health in the probiotic group. Interestingly, no changes in the microbiome of the probiotic group were seen, suggesting that the observed effects may be mediated via the immune system.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Research indicates a bidirectional interaction between the gut microbiome and the central nervous system, affecting the functions of the brain and spinal cord.
- This clinical trial suggests that daily intake of Lactococcus lactis subsp. cremoris (YRC3780) may enhance the HPA axis response to acute psychological stress, potentially linked to a reduction in morning cortisol levels.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
A randomized, placebo-controlled, double-blind clinical trial was conducted to investigate the influence of Lactococcus lactis subsp. cremoris (YRC3780), isolated from kefir, on stress response, sleep quality, and mental health.
Method
Twenty-seven healthy young men, with an average age of 23.5 years, and mean body mass index of 21.5 kg/m2 , were randomly assigned to either the YRC3780 group or the placebo group. Participants were administered YRC3780 or a placebo daily for 8 weeks.
Throughout the study, participants completed assessments, including the Athens Insomnia Scale (AIS), the Pittsburgh Sleep Quality Index (PSQI), the General Health Questionnaire (GHQ-28), and the Profile of Mood States 2nd Edition-Adult Short, Total Mood Disturbance subscale (POMS 2 TMD), every 2 weeks. Additionally, diurnal rhythms of HPA axis activity were assessed every 2 weeks through saliva samples collected at 2-hour intervals during the day. At the end of the 8-week supplementation period, participants underwent the Trier Social Stress Test (TSST) to evaluate the effects of daily YRC3780 intake on the HPA axis stress response. In addition, three fecal samples were collected to analyse the gut microbiome (on the last day of baseline, and at 4 and 8 weeks).
A total of 27 out of 33 subjects (81%) completed the study, with six participants withdrawing without providing explanations.
Results
The primary findings of this study were as follows:
- At week 6 of YRC3780 supplementation, salivary cortisol levels at 2 hours and 6 hours after waking were significantly lower in the YRC3780 group compared to the placebo group (p=0.05).
- Salivary cortisol concentrations at 40 minutes after the TSST were significantly lower in the YRC3780 group (4.2 ± 4.4 nmol/L, mean ± SD) than in the placebo group (7.6 ± 4.7 nmol/L) (p=0.043).
- AIS scores at 6 weeks and GHQ-28 scores at 8 weeks were significantly lower in the YRC3780 group compared to the placebo group (AIS, p=0.031; GHQ-28, p=0.038) indicating better sleep quality and a better mental state.
Conclusion:
Oral supplementation with YRC3780 may have beneficial effects on the HPA axis response to acute psychological stress, potentially associated with a decrease in morning cortisol levels. Additionally, the study suggests that the lower basal activity and stress reactivity of the HPA axis may lead to improvements in subjective sleep quality and mental health.
Clinical practice applications:
- The precise mechanisms underlying the correlation between the gut microbiota and the gut-brain axis remain incompletely understood, emphasising the need for further research.
- This clinical trial demonstrated that daily intake of YRC3780 decreased morning salivary cortisol levels at 6 and 8 weeks and reduced the salivary cortisol response to acute psychological stress.
Considerations for future research:
- Larger, adequately powered clinical trials are required to provide deeper insights into the mechanisms responsible for the stress-reducing and sleep-improving effects of Lactococcus lactis subsp. cremoris.
- Furthermore, investigations into optimal dosage and duration of probiotic supplementation are warranted for a more comprehensive understanding, particularly in diverse demographic groups.
- Comparative research is needed to explore the effects of various probiotic strains on objective stress responses.
Abstract
BACKGROUND Lactococcus lactis subsp. cremoris (YRC3780), which is isolated from kefir, has been associated with anti-allergic effects in humans. However, it remains unknown whether daily intake of YRC3780 attenuates the response to psychological stress in humans in parallel with changes to the gut microbiome. We examined the fundamental role of YRC3780 in the gut microbiome, stress response, sleep, and mental health in humans. METHODS Effects of daily intake of YRC3780 on the hypothalamic-pituitary-adrenal (HPA) axis response to acute psychological stress were investigated in a double-blind, placebo-controlled clinical trial involving 27 healthy young men (mean age and body mass index: 23.5 years and 21.5 kg/m2) who were randomly assigned to placebo (n = 13) or YRC3780 (n = 14) groups. The HPA axis response to acute psychological stress, the diurnal rhythm of HPA axis activity, and gut microbiome were assessed and compared between the two groups. RESULTS The results showed that daily intake of YRC3780 significantly lowered morning salivary cortisol levels compared with placebo. In addition, salivary cortisol levels following a social stress test significantly decreased +40 min after beginning the TSST in the YRC3780-treated group compared to placebo. There were no significant differences between the two groups in terms of actigraphy-based sleep quality, but the subjective sleep quality and mental health were significantly improved in the YRC3780-treated group compared to placebo. CONCLUSIONS Our study suggests that daily intake of YRC3780 improves the HPA axis response to acute psychological stress, which might be associated with a decrease in morning cortisol levels.
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Effect of physical fitness on colorectal tumor development in patients with familial adenomatous polyposis.
Nakamura, T, Ishikawa, H, Sakai, T, Ayabe, M, Wakabayashi, K, Mutoh, M, Matsuura, N
Medicine. 2019;98(38):e17076
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Plain language summary
Familial adenomatous polyposis (FAP), is a rare genetic disease leading to a very high risk of developing colorectal cancer (CRC), with about half of all these patients developing cancer by the age of 40 years. Research has shown that exercise and physical fitness can reduce the risk of sporadic CRC. The aim of this cross-sectional study was to examine the relationship between physical fitness and CRC development in patients with FAP. 119 patients with FAP participated in the study and underwent an exercise stress test to determine physical fitness. The risk of CRC was significantly higher in those who were less physically fit. There was also a significant negative correlation between maximum polyp diameter and physical fitness. The authors conclude that physical fitness may play a role not only in the development of sporadic CRC, but also in cancer development in FAP. The mechanism by which physical fitness prevents the development of CRC and adenoma is largely unknown, but it is thought that improved insulin resistance and altered intestinal transit time may mediate the association.
Abstract
Although accumulated epidemiological evidence indicates that a good physical fitness level may prevent the development of sporadic colorectal cancer (CRC), few studies have examined the effect of physical fitness level on familial adenomatous polyposis (FAP). This cross-sectional study aimed to examine the relationship between physical fitness and CRC development in patients with FAP.A total of 119 patients (54 male; 65 female) with FAP, aged 17 to 73 years, underwent a step test to induce exercise stress. Predicted maximal oxygen uptake (VO2max) was calculated for each patient by using heart rate as an index of physical fitness. The association of VO2max with the presence or absence of CRC and polyp diameter was examined. Patients with FAP were divided into 3 categories according to their VO2max (high, medium, and low). The association between maximum polyp size and VO2max among the patients with FAP without a history of colectomy was examined.The risk of CRC was significantly higher in the low VO2max group than in the high VO2max group (odds ratio = 4.07; 95% confidence interval, 1.02-16.26). The maximum polyp diameter was significantly negatively correlated with the VO2max among the patients with FAP without a history of colectomy (r = -.44, P = .01). In the multiple linear regression analysis, maximum polyp diameter was independently correlated with VO2max.Our results suggest a preventive association between physical fitness and CRC development or colorectal adenoma growth exists in patients with FAP.
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Impact of Diarrhea after Drinking on Colorectal Tumor Risk: A Case Control Study.
Shiotani, A, Ishikawa, H, Mutoh, M, Takeshita, T, Nakamura, T, Morimoto, K, Sakai, T, Wakabayashi, K, Matsuura, N
Asian Pacific journal of cancer prevention : APJCP. 2019;(3):795-799
Abstract
Background: Recently, the number of colorectal cancer (CRC) cases in Japan has been increasing, and is strongly influenced by alcohol consumption. On the other hand, there are several reports suggesting a relationship between bowel movement (constipation and diarrhea) and CRC development. Moreover, it is generally known that diarrhea may occur after drinking. However, the mechanism by which drinking alcohol increases CRC is not fully clarified yet. We hypothesized that diarrhea after drinking may play an important role in colorectal carcinogenesis. Methods: We examined the presence of diarrhea after drinking and further evaluated the correlation of diarrhea after drinking with the incidence of colorectal tumors. To obtain the status of the feces, a self-recorded questionnaire survey was administered using the dietary-recording method. Blood samples were obtained to analyze the ALDH2 Glu504Lys and ADH1B His48Arg polymorphisms. Results: The participants were 417 patients who had undergone a total colonoscopy. The control was selected from 186 patients who underwent a medical checkup at the same hospital during the same time period. The odds ratio for all subjects was 2.1 (95% CI: 1.18 - 3.80), and that for heavy drinkers was 4.2 (1.48 - 11. 90). Conclusions: The results demonstrated that those who have diarrhea after drinking possess a high risk of developing colon tumors.
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The incidences of and risk factors for severe retinopathy requiring photocoagulation and albuminuria in Japanese patients with childhood-onset type 1 diabetes.
Takaike, H, Uchigata, Y, Matsuura, N, Sasaki, N, Amemiya, S, Urakami, T, Kawamura, T, Kikuchi, N, Sugihara, S, ,
Diabetology international. 2018;(2):121-128
Abstract
The aim of this study was to clarify the incidences of and the risk factors for severe retinopathy requiring photocoagulation therapy and albuminuria in Japanese patients with childhood-onset type 1 diabetes mellitus. A total of 756 patients from a cohort study by the Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes were included in the study. Patients were registered in 1995 or 2000, and HbA1cwas measured every 4 months and analyzed in central hospital for an average of 6 years. The presence of severe retinopathy requiring laser photocoagulation and the presence of albuminuria was checked for during the period 2010-2011. During a median of 18 (range: 15-21) years, 34 out of 756 patients underwent laser photocoagulation and 57 out of 605 patients developed albuminuria. A Cox proportional hazards model showed that the risk of severe retinopathy requiring laser photocoagulation increased by 1.15 (95% confidence interval [CI] 1.03-1.29, p = 0.012) with each increase of a year in the age at onset, by 4.03 (95% CI 1.20-13.5, p = 0.024) in females, and by 2.05 (95% CI 1.69-2.49, p < 0.0001) with each increase of 1% in HbA1c. The risk of albuminuria increased significantly, by 1.09 (95% CI 1.01-1.18 p = 0.037), with each increase of a year in the age at onset and by 2.38 (95% CI 1.93-2.97 p < 0.0001) with each increase of 1% in HbA1c. In Japanese patients with childhood-onset type 1 diabetes, older age at the onset of diabetes, female rather than male gender, and higher HbA1c were found to increase the risk of requiring photocoagulation. No patients with HbA1c < 7.5% developed severe retinopathy requiring photocoagulation therapy. The risk of developing albuminuria increased with age at onset of diabetes and HbA1c. Female gender was a strong risk factor for severe retinopathy requiring photocoagulation, but not for albuminuria.