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Naturalization of the microbiota developmental trajectory of Cesarean-born neonates after vaginal seeding.
Song, SJ, Wang, J, Martino, C, Jiang, L, Thompson, WK, Shenhav, L, McDonald, D, Marotz, C, Harris, PR, Hernandez, CD, et al
Med (New York, N.Y.). 2021;2(8):951-964.e5
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Studies on model organisms show that foetal development can be modulated by microbial products from the pregnant mother’s microbiota, and early colonisation is critical for immune system development. However, natural transmission and colonisation of maternal microbes is impaired by caesarean section (CS) delivery. The aim of this study was to determine the effect of restoring exposure to maternal vaginal fluids after CS birth. This study is a large observational study of 177 infants born to 174 mothers. Physicians assessed healthy mothers who were set to deliver vaginally or by scheduled CS. Results demonstrate that microbial differences associated with delivery mode can be reduced by exposure to a vaginal microbial source at birth. In fact, birth mode significantly differentiated infant gut and skin microbiome development, and that seeding worked to adjust the trajectory of CS-delivered infants through partial restoration of microbiome features associated with a vaginal delivery. Authors conclude that restoring natural exposures at birth may be one way to reduce the risk of CS-associated diseases such as obesity, asthma, allergies, and immune disfunctions. However, randomised clinical trials on large cohorts are needed to gain conclusive evidence for microbial restoration at birth improving health outcomes.
Abstract
BACKGROUND Early microbiota perturbations are associated with disorders that involve immunological underpinnings. Cesarean section (CS)-born babies show altered microbiota development in relation to babies born vaginally. Here we present the first statistically powered longitudinal study to determine the effect of restoring exposure to maternal vaginal fluids after CS birth. METHODS Using 16S rRNA gene sequencing, we followed the microbial trajectories of multiple body sites in 177 babies over the first year of life; 98 were born vaginally, and 79 were born by CS, of whom 30 were swabbed with a maternal vaginal gauze right after birth. FINDINGS Compositional tensor factorization analysis confirmed that microbiota trajectories of exposed CS-born babies aligned more closely with that of vaginally born babies. Interestingly, the majority of amplicon sequence variants from maternal vaginal microbiomes on the day of birth were shared with other maternal sites, in contrast to non-pregnant women from the Human Microbiome Project (HMP) study. CONCLUSIONS The results of this observational study prompt urgent randomized clinical trials to test whether microbial restoration reduces the increased disease risk associated with CS birth and the underlying mechanisms. It also provides evidence of the pluripotential nature of maternal vaginal fluids to provide pioneer bacterial colonizers for the newborn body sites. This is the first study showing long-term naturalization of the microbiota of CS-born infants by restoring microbial exposure at birth. FUNDING C&D, Emch Fund, CIFAR, Chilean CONICYT and SOCHIPE, Norwegian Institute of Public Health, Emerald Foundation, NIH, National Institute of Justice, Janssen.
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Impact of Experimentally Induced Cognitive Dietary Restraint on Eating Behavior Traits, Appetite Sensations, and Markers of Stress during Energy Restriction in Overweight/Obese Women.
Morin, I, Bégin, C, Maltais-Giguère, J, Bédard, A, Tchernof, A, Lemieux, S
Journal of obesity. 2018;2018:4259389
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The treatment of obesity has become a public health priority given the negative impact of this condition on physical and mental health. The aim of this study was to compare the effects of energy restriction alone or in combination with induced cognitive dietary restraint (CDR) on eating behaviour traits, appetite sensations, and markers of stress in overweight and obese premenopausal women. The study is a single-blinded randomised clinical study which recruited premenopausal women aged between 26 and 50 years. The participants were randomised to either an energy-restriction-plus-induced CDR condition (CDR+group) or an energy-restriction-without induced CDR condition (CDR−group). Results indicate that inducing CDR in a context of energy restriction had no further effects on eating behaviour traits, appetite sensations, and markers of stress in the short term as well as in the longer term than energy restriction alone. Authors conclude that increasing CDR has no negative impact on factors regulating energy balance in the context of energy restriction.
Abstract
Weight loss has been associated with changes in eating behaviors and appetite sensations that favor a regain in body weight. Since traditional weight loss approaches emphasize the importance of increasing cognitive dietary restraint (CDR) to achieve negative energy imbalance, it is difficult to untangle the respective contributions of energy restriction and increases in CDR on factors that can eventually lead to body weight regain. The present study aimed at comparing the effects of energy restriction alone or in combination with experimentally induced CDR on eating behavior traits, appetite sensations, and markers of stress in overweight and obese women. We hypothesized that the combination of energy restriction and induced CDR would lead to more prevalent food cravings, increased appetite sensations, and higher cortisol concentrations than when energy restriction is not coupled with induced CDR. A total of 60 premenopausal women (mean BMI: 32.0 kg/m2; mean age: 39.4 y) were provided with a low energy density diet corresponding to 85% of their energy needs during a 4-week fully controlled period. At the same time, women were randomized to either a condition inducing an increase in CDR (CDR+ group) or a condition in which CDR was not induced (CRD- group). Eating behavior traits (Three-Factor Eating Questionnaire and Food Craving Questionnaire), appetite sensations (after standardized breakfast), and markers of stress (Perceived Stress Scale; postawakening salivary cortisol) were measured before (T = 0 week) and after (T = 4 weeks) the 4-week energy restriction, as well as 3 months later. There was an increase in CDR in the CDR+ group while no such change was observed in the CDR- group (p=0.0037). No between-group differences were observed for disinhibition, hunger, cravings, appetite sensations, perceived stress, and cortisol concentrations. These results suggest that a slight increase in CDR has no negative impact on factors regulating energy balance in the context of energy restriction.
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A sympathetic nervous system evaluation of obesity stigma.
Oliver, MD, Datta, S, Baldwin, DR
PloS one. 2017;12(10):e0185703
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The negative health consequences of obesity are well known. Those classified as obese also suffer from discrimination which has further negative psychological and physiological effects on well-being. The aim of this study was to see if attitudes to obesity can be modified at the physiological and psychological level by priming. 70 people aged 18-53 were randomly assigned to 2 groups. One group was shown images of obesity in negative settings, the other in positive settings. All participants then viewed an actual obesity discrimination incident. Levels of the digestive enzyme salivary alpha amylase (sAA) and skin conductance (SC) were taken as measures of sympathetic nervous system (SNS) activity. Individuals in the negative priming group had significantly more SC arousal and exhibited the highest overall sAA response after viewing the incident when compared to the positively primed group. The authors conclude that clinicians addressing stigma issues should consider the use of positively primed images as a method for reducing the possible long-term physiological consequences of the negative attitudes surrounding obesity.
Abstract
The portrayal of obesity in the media is often one of negativity. Consequently, it may generate an increase in stigma. Obesity stigma, a form of social discrimination, is responsible for many of the negative psychological and physiological effects on individual wellness. These effects not only impact individual health, but also affect the economy, and ultimately, societal wellness. In an attempt to examine the influence of the media on obesity stigma, this study tested the hypothesis that positive priming would lead to a reduction in obesity stigma. To further our understanding of this relationship, we: 1) examined the role of priming on physiological measures (e.g. salivary alpha amylase and skin conductance) in 70 college students by introducing positive and negative media images of individuals with obesity, and 2) assessed psychological measures (e.g. perceived stress, need to belong, and self-esteem, and Body Mass Index). After the priming manipulation, participants read a vignette depicting the discrimination of an individual with obesity and answered subsequent questions assessing participants' attributional blame of obesity. Results of this study revealed that priming affects physiological responding to obesity stigmatization. In conclusion, these findings suggest that incorporating positive media images of individuals with obesity may be an effective tool for reducing stigma and the various physiological consequences associated with it, which in turn, can enhance societal health and wellness.
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No effect of caloric restriction on salivary cortisol levels in overweight men and women.
Tam, CS, Frost, EA, Xie, W, Rood, J, Ravussin, E, Redman, LM
Metabolism: clinical and experimental. 2014;63(2):194-8
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Alterations in normal cortisol patterns have been observed in people who are obese. The effect of weight loss on cortisol levels, a measure of hypothalamic pituitary adrenal (HPA) activity, in overweight individuals is not known. The aim of this study was to test the hypothesis that 6 months of moderate caloric restriction would alter morning and diurnal salivary cortisol levels. Thirty-five overweight adults (average BMI 27.8 kg/m2) took part in this randomised control trial. Participants were assigned to either calorie restriction (CR: 25% reduction in energy intake), calorie restriction+exercise (CR+EX: 12.5% reduction in energy intake+12.5% increase in exercise energy expenditure) or control (healthy weight-maintenance diet) for 6 months. Salivary cortisol was measured at 8:00, 8:30, 11:00, 11:30, 12:30, 13:00, 16:00 and 16:30. Morning cortisol was defined as the mean cortisol concentration at 08:00 and 08:30. Diurnal cortisol was calculated as the mean of the 8 cortisol measures across the day. Across all groups, higher morning and diurnal cortisol levels were associated with impaired insulin sensitivity. There was no significant effect of group, time or sex on morning or diurnal cortisol levels. The authors concluded that a 10% weight loss with a 25% CR diet alone or with exercise did not impact morning or diurnal salivary cortisol levels in overweight individuals. Their findings suggest that prolonged restriction of energy intake is not perceived by the body as a stressor, and therefore CR may present a viable intervention.
Abstract
OBJECTIVE The effect of weight loss by diet or diet and exercise on salivary cortisol levels, a measure of hypothalamic pituitary adrenal activity, in overweight individuals is not known. The objective was to test the hypothesis that 24 weeks of moderate caloric restriction (CR) (25%) by diet or diet and aerobic exercise would alter morning and diurnal salivary cortisol levels. DESIGN AND SETTING Randomized control trial in an institutional research center. PARTICIPANTS Thirty-five overweight (BMI: 27.8±0.7 kg/m(2)) but otherwise healthy participants (16 M/19 F). INTERVENTION Participants were randomized to either calorie restriction (CR: 25% reduction in energy intake, n=12), calorie restriction+exercise (CR+EX: 12.5% reduction in energy intake+12.5% increase in exercise energy expenditure, n=12) or control (healthy weight-maintenance diet, n=11) for 6 months. MAIN OUTCOME MEASURE Salivary cortisol measured at 8:00, 8:30, 11:00, 11:30, 12:30, 13:00, 16:00 and 16:30. Morning cortisol was defined as the mean cortisol concentration at 08:00 and 08:30. Diurnal cortisol was calculated as the mean of the 8 cortisol measures across the day. RESULTS In the whole cohort, higher morning and diurnal cortisol levels were associated with impaired insulin sensitivity (morning: P=0.004, r(2)=0.24; diurnal: P=0.02, r(2)=0.15). Using mixed model analysis, there was no significant effect of group, time or sex on morning or diurnal cortisol levels. CONCLUSION A 10% weight loss with a 25% CR diet alone or with exercise did not impact morning or diurnal salivary cortisol levels.
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Sleep restriction for 1 week reduces insulin sensitivity in healthy men.
Buxton, OM, Pavlova, M, Reid, EW, Wang, W, Simonson, DC, Adler, GK
Diabetes. 2010;59(9):2126-33
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Short sleep duration is associated with an increased risk of many chronic diseases including diabetes, however the effects of sleep restriction on insulin sensitivity have not yet been established. The aim of study was to assess the effects of decreased sleep duration on insulin sensitivity in a controlled environment. This 12-day inpatient study included 20 healthy men who were randmoised to receive a wakefulness-promoting drug, modafinil, or placebo during the sleep restriction phase. This study showed that sleep restriction for one week significantly reduces insulin sensitivity. These findings raise concerns about chronic insufficient sleep on the development of metabolic diseases and promote further research into these effects.
Abstract
OBJECTIVE Short sleep duration is associated with impaired glucose tolerance and an increased risk of diabetes. The effects of sleep restriction on insulin sensitivity have not been established. This study tests the hypothesis that decreasing nighttime sleep duration reduces insulin sensitivity and assesses the effects of a drug, modafinil, that increases alertness during wakefulness. RESEARCH DESIGN AND METHODS This 12-day inpatient General Clinical Research Center study included 20 healthy men (age 20-35 years and BMI 20-30 kg/m(2)). Subjects spent 10 h/night in bed for >or=8 nights including three inpatient nights (sleep-replete condition), followed by 5 h/night in bed for 7 nights (sleep-restricted condition). Subjects received 300 mg/day modafinil or placebo during sleep restriction. Diet and activity were controlled. On the last 2 days of each condition, we assessed glucose metabolism by intravenous glucose tolerance test (IVGTT) and euglycemic-hyperinsulinemic clamp. Salivary cortisol, 24-h urinary catecholamines, and neurobehavioral performance were measured. RESULTS IVGTT-derived insulin sensitivity was reduced by (means +/- SD) 20 +/- 24% after sleep restriction (P = 0.001), without significant alterations in the insulin secretory response. Similarly, insulin sensitivity assessed by clamp was reduced by 11 +/- 5.5% (P < 0.04) after sleep restriction. Glucose tolerance and the disposition index were reduced by sleep restriction. These outcomes were not affected by modafinil treatment. Changes in insulin sensitivity did not correlate with changes in salivary cortisol (increase of 51 +/- 8% with sleep restriction, P < 0.02), urinary catecholamines, or slow wave sleep. CONCLUSIONS Sleep restriction (5 h/night) for 1 week significantly reduces insulin sensitivity, raising concerns about effects of chronic insufficient sleep on disease processes associated with insulin resistance.