Helene Sauer

A vegan or vegetarian diet substantially alters the human colonic faecal microbiota

Background/Objectives:Consisting of ∼1014 microbial cells, the intestinal microbiota represents the largest and the most complex microbial community inhabiting the human body. However, the influence of regular diets on the microbiota is widely unknown.Subjects/Methods:We examined faecal samples of vegetarians (n=144), vegans (n=105) and an equal number of control subjects consuming ordinary omnivorous diet who were matched for age and gender. We used classical bacteriological isolation, identification and enumeration of the main anaerobic and aerobic bacterial genera and computed absolute and relative numbers that were compared between groups.Results:Total counts of Bacteroides spp., Bifidobacterium spp., Escherichia coli and Enterobacteriaceae spp. were significantly lower (P=0.001, P=0.002, P=0.006 and P=0.008, respectively) in vegan samples than in controls, whereas others (E. coli biovars, Klebsiella spp., Enterobacter spp., other Enterobacteriaceae, Enterococcus spp., Lactobacillus spp., Citrobacter spp. and Clostridium spp.) were not. Subjects on a vegetarian diet ranked between vegans and controls. The total microbial count did not differ between the groups. In addition, subjects on a vegan or vegetarian diet showed significantly (P=0.0001) lower stool pH than did controls, and stool pH and counts of E. coli and Enterobacteriaceae were significantly correlated across all subgroups.Conclusions:Maintaining a strict vegan or vegetarian diet results in a significant shift in the microbiota while total cell numbers remain unaltered.

Effects of short-term food deprivation on interoceptive awareness, feelings and autonomic cardiac activity.

The perception of internal bodily signals (interoception) plays a relevant role for emotion processing and feelings. This study investigated changes of interoceptive awareness and cardiac autonomic activity induced by short-term food deprivation and its relationship to hunger and affective experience. 20 healthy women were exposed to 24h of food deprivation in a controlled setting. Interoceptive awareness was assessed by using a heartbeat tracking task. Felt hunger, cardiac autonomic activity, mood and subjective appraisal of interoceptive sensations were assessed before and after fasting. Results show that short-term fasting intensifies interoceptive awareness, not restricted to food cues, via changes of autonomic cardiac and/or cardiodynamic activity. The increase of interoceptive awareness was positively related to felt hunger. Additionally, the results demonstrate the role of cardiac vagal activity as a potential index of emotion related self-regulation, for hunger, mood and the affective appraisal of interoceptive signals during acute fasting.

A comparative analysis of anorexia nervosa groups on Facebook

PurposeTo analyze the content and culture of anorexia nervosa (AN)-related communication on the current major social network site (SNS) Facebook.MethodsWe searched for groups and sites related to AN on Facebook by means of a faux profile of a young female. Identified groups/sites were analyzed with respect to (1) category (education, self-help, professional help, pro-ana, anti pro-ana), (2) activity, (3) motivational aspects (prose, pictures), and (4) social support.ResultsNumerous relevant groups were found in all categories except that professional help was almost nonexistent. Pro-ana groups were found to be the most active, best organized, and offered the highest levels of social support. Prose motivation was distinctly offered in all categories. Motivation with pictures was particularly evident in pro-ana groups. The most functional motivation was found in self-help groups.ConclusionsSNS appears to be a relevant way for young females suffering from AN to communicate and exchange disease and health-related ideas. Caregivers, researchers, and institutions in the field of eating disorders should be aware of the existence, possibilities, dysfunctions, and influence of SNS. Whether SNS can help persons with AN to get therapeutic assistance as well as whether it can be integrated into psychotherapeutic strategies should be examined in future studies.

A 1-year videoconferencing-based psychoeducational group intervention following bariatric surgery: results of a randomized controlled study.

BACKGROUND For severely obese patients, bariatric surgery has been recommended as an effective therapy. OBJECTIVES The Bariataric Surgery and Education (BaSE) study aimed to assess the efficacy of a videoconferencing-based psychoeducational group intervention in patients after bariatric surgery. SETTING The BaSE study is a randomized, controlled multicenter clinical trial involving 117 patients undergoing bariatric surgery (mean preoperative body mass index [BMI] 49.9 kg/m(2), SD 6.4). Patients were enrolled between May 2009 and November 2012 and were randomly assigned to receive either conventional postsurgical visits or, in addition, a videoconferencing-based 1-year group program. METHODS Primary outcome measures were weight in kilograms, health-related quality of life (HRQOL), and general self-efficacy (GSE). Secondary outcome measures were depression symptoms and eating behavior. RESULTS 94% of the patients completed the study. Mean weight loss for all patients was 45.9 kg (SD 16.4) 1 year after surgery (mean excess weight loss [EWL] 63%). Intention-to-treat analyses revealed no differences in weight loss, EWL, HRQOL, or self-efficacy between study groups at 1 year after surgery. However, patients with clinically significant depression symptoms (CSD) at baseline assigned to the intervention group (n = 29) had a significantly better HRQOL (P = .03), lower depression scores (P = .02), and a trend for a better EWL (.06) 1 year after surgery compared with the control group (n = 20). CONCLUSION We could not prove the efficacy of the group program for the whole study sample. However, results indicate that the intervention is effective for the important subgroup of patients with CSD.

Obese children and adolescents need increased gastric volumes in order to perceive satiety.

In order to develop effective weight management strategies, it is important to identify factors that influence energy intake. Portion size has been discussed as one such factor. To date, most studies focusing on the relationship between portion size, energy intake, and weight have analyzed questionnaire data and 24‐h records. In this study, we assessed the onset of satiety using the water‐load test in normal‐weight and obese children and adolescents.

Dopamine Depletion Reduces Food-Related Reward Activity Independent of BMI

Reward sensitivity and possible alterations in the dopaminergic-reward system are associated with obesity. We therefore aimed to investigate the influence of dopamine depletion on food-reward processing. We investigated 34 female subjects in a randomized placebo-controlled, within-subject design (body mass index (BMI)=27.0 kg/m2 ±4.79 SD; age=28 years ±4.97 SD) using an acute phenylalanine/tyrosine depletion drink representing dopamine depletion and a balanced amino acid drink as the control condition. Brain activity was measured with functional magnetic resonance imaging during a ‘wanting’ and ‘liking’ rating of food items. Eating behavior-related traits and states were assessed on the basis of questionnaires. Dopamine depletion resulted in reduced activation in the striatum and higher activation in the superior frontal gyrus independent of BMI. Brain activity during the wanting task activated a more distributed network than during the liking task. This network included gustatory, memory, visual, reward, and frontal regions. An interaction effect of dopamine depletion and the wanting/liking task was observed in the hippocampus. The interaction with the covariate BMI was significant in motor and control regions but not in the striatum. Our results support the notion of altered brain activity in the reward and prefrontal network with blunted dopaminergic action during food-reward processing. This effect is, however, independent of BMI, which contradicts the reward-deficiency hypothesis. This hints to the hypothesis suggesting a different or more complex mechanism underlying the dopaminergic reward function in obesity.

PreDictor Research in Obesity during Medical care - weight Loss in children and adolescents during an INpatient rehabilitation: rationale and design of the DROMLIN study

BackgroundObesity in adults and children is increasing worldwide at alarming rates. Obese children and adolescents are likely to become obese adults with increased risk of a number of comorbidities. In addition to preventing the development of obesity at young age, it is necessary to individualize the therapy of already obese children and adolescents in order to increase the likelihood of weight loss and maintenance. Therefore, the aim of this study is to identify predictors which play a significant role in successful weight loss and weight loss maintenance in children and adolescents.Methods/DesignOver a one year period, 60 obese children and adolescents between 9 to 17 years of age shall be recruited at an inpatient children rehabilitation facility in Germany. They will be investigated twice within a few days following admission and prior to discharge. The study will be an integrated component of an established inpatient weight-loss and in part psychosomatic therapy. The collected data can be grouped into four clusters: 1) demographic, sociometric and psychometric data, 2) objective and subjective parameters of body condition, 3) autonomic nervous system regulated functions and 4) objective and subjective parameters for eating behavior. Primary outcome is the change of the body mass index standard deviation score (BMI-SDS). In order to evaluate the data appropriately, all examinations will be also conducted in a normal-weight reference group, matched for age and gender.DiscussionFor some of the collected parameters the time span between measures may be too short. Therefore, a 6 months, 1 year and 2 year follow-up will be performed for evaluating the different predictors and their influence in regard to a successful intervention. Further middle- and long-term follow-up studies are planned.Trial RegistrationThe study protocol was approved by the Ethics Committee of the University Hospital Tübingen, Germany. This study is registered at the German Clinical Trials Register (DRKS) with the clinical trial numberDRKS00005122.

Effect of a weight reduction program on baseline and stress-induced heart rate variability in children with obesity.

Autonomic dysregulation is a well‐established feature in adults with obesity but not in children. Since this dysregulation could contribute to weight dynamics, this study aimed to compare autonomic regulation in children with obesity and normal‐weight peers and to track autonomic status during weight reduction.

Changes in Gustatory Function and Taste Preference Following Weight Loss.

Objective To investigate taste changes of obese children during an inpatient weight reduction treatment in comparison with normal weight children. Study design Obese (n = 60) and normal weight (n = 27) children aged 9‐17 years were assessed for gustatory functions using taste strips (taste identification test for the taste qualities sour, salty, sweet, and bitter), taste preferences, and experienced taste sensitivity. Obese children were examined upon admission (T1) and before discharge (T2). Normal weight children served as the control group. Results Irrespective of taste quality, obese children exhibited a lower ability to identify taste (total taste score) than normal weight children (P < .01); this overall score remained stable during inpatient treatment in obese children. Group and treatment effects were seen when evaluating individual taste qualities. In comparison with normal weight children, obese children exhibited poorer sour taste identification performance (P < .01). Obese children showed improvement in sour taste identification (P < .001) and deterioration in sweet taste identification (P < .001) following treatment. Subjective reports revealed a lower preference for sour taste in obese children compared with normal weight children (P < .05). The sweet and bitter taste ability at T1 predicted the body mass index z score at T2 (R2 = .23, P < .01). Conclusions We identified differences in the ability to discriminate tastes and in subjective taste perception between groups. Our findings of increased sour and reduced sweet taste discrimination after the intervention in obese children are indicative of an exposure‐related effect on taste performance, possibly mediated by increased acid and reduced sugar consumption during the intervention. Because the sweet and bitter taste ability at T1 predicted weight loss, addressing gustatory function could be relevant in individualized obesity treatment approaches. Trial registration Germanctr.de: DRKS00005122.

Almost Nothing - Not Even Bariatric Surgery for Obesity - Changes Olfactory Sensitivity

Altered olfactory functions in patients with eating disorders have been reported with obesity, during hunger, following food ingestion and after bariatric surgery, but subsequent data have remained controversial. Methods : We investigated olfactory function (threshold, identification, discrimination) by Sniffin Sticks® in six independent studies: At baseline and 24 h and 48 h after a zero-calorie fasting (Study 1); fasted and after a 3810 kJ mixed meal (Study 2); twice after a 2510 kJ mixed meal supplemented with either 40 g saturated or unsaturated fatty acids (Study 3); prior to and after rotation-induced nausea (Study 4); at baseline and after a 5-day 6° head-down tilt bedrest (HDT-BR) and a high (7.7 mmol/kg BW/d) and low (0.7 mmol/kg BW/d) sodium diet (Study 5). We also compared odor sensitivity before and 12 months after bariatric (sleeve) surgery in patients with morbid obesity (Study 6). Results : Fasting (Study 1) did not alter olfactory functions, and a highcalorie diet (Study 2) moderately improved odor discrimination only; saturated fatty acids (Study 3) marginally improved odor identification, while the induction of nausea (Study 4) did not affect olfaction. HDT-BR (Study 5) significantly reduced the olfactory thresholds as well as the total score, mainly due to the bedrest component. Bariatric surgery (Study 6) did not change odor sensitivity, but some morbidly obese patients exhibited abnormally low olfactory functions prior to and after surgery. Conclusions : Manipulation of the hunger/satiety state has only marginal effects on olfactory functions in normal healthy volunteers and obese patients.