Sibylle Klosterhalfen

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.

Pavlovian conditioning of immunosuppression modifies adjuvant arthritis in rats.

Ten days prior to induction of adjuvant arthritis (by injection of complete Freunds adjuvant into a rats hind paw), three groups of rats were dosed with cyclophosphamide (CY), an immunosuppressive drug. A saccharin/vanilla solution (SV) was presented either 2 days (Group NC) or immediately before CY treatment (Groups C and C2). Three further SV presentations started either 30 min (Groups C and NC) or 2 days after antigenic stimulation (Group C2). The groups did not differ with respect to the degree of swelling in the injected paws. In contrast, Group C differed significantly from Groups NC and C2 with respect to the uninjected hind paws: Group C showed no external signs of a proliferation of inflammation, whereas approximately half of the animals in the other two groups developed small lesions. A second experiment, similar to the first, yielded the same results. These results essentially confirm previous findings on conditioned immunosuppression and extend them to an inflammatory joint disease.

A mixture of Escherichia coli (DSM 17252) and Enterococcus faecalis (DSM 16440) for treatment of the irritable bowel syndrome--a randomized controlled trial with primary care physicians.

Abstract  Therapy trials with bacterial compounds in irritable bowel syndrome (IBS) have produced conflicting results. This study was performed in 1988 and 1989, and was re‐analysed according to current IBS standards. Two hundred ninety‐seven patients with lower abdominal symptoms diagnosed as IBS were treated for 8 weeks by the compound ProSymbioflor® (Symbiopharm GmbH, Herborn, Germany), an autolysate of cells and cell fragments of Enterococcus faecalis and Escherichia coli, or placebo in a double‐blinded, randomized fashion. Patients were seen weekly by the physician, who assessed the presence of core IBS symptoms. Responders had at least a 50% decrease in global symptom score (GSS) and in abdominal pain score (APS) reports at ≥1 visit during treatment. The responder rate in GSS to the drug was 102/149 (68.5%) in comparison to placebo with 56/148 (37.8%) (P < 0.001), the improvement in APS was 108/149 (72.5%) and 66/148 (44.6%) respectively (P = 0.001). The number‐needed‐to‐treat was 3.27 for GSS and 3.59 for the APS report. Kaplan–Meier analysis revealed a mean response time of 4–5 weeks for active treatment and more than 8 weeks for placebo (P < 0.0001). Treatment of IBS with the bacterial lysate ProSymbioflor is effective and superior to placebo in reducing typical symptoms of IBS patients seen by general practitioners.

The placebo response in clinical trials: more questions than answers

Meta-analyses and re-analyses of trial data have not been able to answer some of the essential questions that would allow prediction of placebo responses in clinical trials. We will confront these questions with current empirical evidence. The most important question asks whether the placebo response rates in the drug arm and in the placebo arm are equal. This ‘additive model’ is a general assumption in almost all placebo-controlled drug trials but has rarely been tested. Secondly, we would like to address whether the placebo response is a function of the likelihood of receiving drug/placebo. Evidence suggests that the number of study arms in a trial may determine the size of the placebo and the drug response. Thirdly, we ask what the size of the placebo response is in ‘comparator’ studies with a direct comparison of a (novel) drug against another drug. Meta-analytic and experimental evidence suggests that comparator studies may produce higher placebo response rates when compared with placebo-controlled trials. Finally, we address the placebo response rate outside the laboratory and outside of trials in clinical routine. This question poses a serious challenge whether the drug response in trials can be taken as evidence of drug effects in clinical routine.

Placebo effects in children: a review

Of more than 155,000 PubMed citations found with the search term “placebo,” only ~9,000 (5.8%) included the terms “children” or “adolescents.” When all these papers were screened, only ~2,000 of them investigated the placebo effect per se, and of those, only ~50 (2.5%) discussed the placebo effect in children and adolescents. In this narrative review, we explore four aspects of the placebo response in children and adolescents: (i) the legal and ethical limitations and restrictions for the inclusion of children in clinical trials as well as in experimental (placebo) research that may explain the poor knowledge base; (ii) the question of whether or not the placebo effect is larger in children and adolescents as compared with adults; (iii) whether the mechanisms underlying the placebo effect are similar between children and adults; and (iv) whether mediators and moderators of the placebo effect are comparable between children and adults. We finally discuss some of the consequences from the current placebo research in adults that may affect both experimental and clinical research in children and adolescents.

Postinfectious irritable bowel syndrome: follow-up of a patient cohort of confirmed cases of bacterial infection with Salmonella or Campylobacter

Background  Gastrointestinal infections have been proposed to predict subsequent irritable bowel syndrome (IBS) but large‐scale infectious events are rare and long‐term data are missing.

Effects of overshadowing on conditioned nausea in cancer patients: an experimental study

The infusion of cytotoxic drugs in cancer patients is often accompanied by posttreatment nausea (PN). In addition, patients complain about nausea prior to an infusion [i.e., anticipatory nausea (AN)]. AN is mainly explained by classical conditioning, with the infusion as the unconditioned stimulus (US) and with the stimuli signaling the infusion as conditioned stimuli (CS). Despite this conditioning etiology, a specifically derived therapy to attenuate the CS-US contingency is missing. The purpose of this study is to develop and to test an overshadowing procedure for prevention of AN, and also for the modification of PN intensity. Sixteen cancer patients were assigned to one of two groups: Overshadowing+ (OV+) and Overshadowing- (OV-). At the start of all infusions of two consecutive chemotherapy cycles A and B (acquisition), OV+ subjects drank a saliently tasting beverage (the overshadowing CS), whereas group OV- drank water. All patients received water in cycle C (test). Self-reported symptoms and heart rates were recorded. As expected, in cycle C (test), no patient of group OV+ showed AN, whereas two patients of group OV- developed AN. There was a tendency for a reduction of the intensity of PN, in terms of duration and latency after overshadowing, in cycle C: OV+ patients tended to show a shorter duration and a longer latency between end of infusion and PN onset. In OV-, there was a significantly larger heart rate deceleration in both measurement periods, in the anticipatory and the posttreatment measurement period. Data suggest to apply overshadowing for prevention of AN and modification of PN. Physiological markers of conditioned nausea are revealed. After its procedural implementation, the technique can be used in larger samples now.

Randomized Controlled Treatment Trial of Irritable Bowel Syndrome with a Probiotic E.-coli Preparation (DSM17252) Compared to Placebo.

BACKGROUND Therapy trials with bacterial compounds in irritable bowel syndrome (IBS) have produced conflicting results and, so far, an E.-coli preparation has not been used. METHODS Two hundred and ninety-eight patients with lower abdominal symptoms diagnosed as IBS were treated for 8 weeks by the compound Symbioflor-2 (Symbiopharm GmbH, Herborn, Germany), an Escherichia coli product (N = 148), or placebo (n = 150) in a double-blinded, randomized fashion. Patients were seen weekly by the physician, who assessed the presence of core IBS symptoms. Both an abdominal pain score (APS) as well as a general symptom score (GSS) were used as primary endpoints. Responders had to have complete absence of IBS core symptoms at > or = 1 visit during treatment. RESULTS The responder rate in GSS to the drug was 27 / 148 (18.2 %) in comparison to placebo with 7 / 150 (4.67 %) (p = 0.000397). The improvement in APS was 28 / 148 (18.9 %) and 10 / 150 (6.67 %) for placebo (p = 0.001649). The response was reached from visit 3 onwards with both medication and placebo. Post-hoc analysis revealed no significant differences in efficacy of the drug between the gender and different age groups. CONCLUSION Treatment of IBS with the probiotic Symbioflor-2 is effective and superior to placebo in reducing typical symptoms of IBS patients seen by general practitioners and by gastroenterologists.

Anticipatory Symptoms and Anticipatory Immune Responses in Pediatric Cancer Patients Receiving Chemotherapy: Features of a Classically Conditioned Response?

UNLABELLED There is considerable evidence from studies in adult patients that classical conditioning contributes to anticipatory nausea and/or vomiting (ANV) in cancer chemotherapy: The stimuli predicting the infusion serve as conditioned stimuli (CS). When reexposed to the CS, some patients experience ANV prior to infusion onset. In adult patients, anticipatory immunomodulation (AIM) has also been observed. The present study examines whether ANV and AIM occur in pediatric cancer patients and whether they show features of a conditioned response. METHODS Nineteen pediatric cancer patients (M = 10.1 years, > 2 previous chemotherapies) were studied over two consecutive cycles (A, B). In both cycles, self-reported symptoms, for example nausea and vomiting, were recorded from two days prior to the onset (Day -2), during infusion, and two days after the end of the infusion (Day +2). In Cycle B, blood was drawn at home at Day -2, and at Day 0 in the hospital prior to infusion onset, thus using a quasi-experimental variation of the CS content of the environment. Immune parameters valid for tumor defense and cytotoxic competence (natural killer cell activity [NKCA], plasma interleukin [IL]-1beta, IL-2, IL-10, interferon [IFN]-gamma, tumor necrosis factor [TNF]-alpha) and cortisol were measured. RESULTS ANV was reported by 7 patients in at least one cycle. In Cycle A, ANV was positively associated with emetogenity of chemotherapy. Features of ANV-duration and occurrence-tended to be positively associated with those of posttreatment nausea and vomiting. AN increased as infusion onset time approached. NKCA and IFN-gamma increased from home to hospital, independent from cortisol level. The NKCA increase was predominantly observed in patients with ANV. CONCLUSIONS ANV in pediatric patients showed features of a CR. Immune parameters were sensitive to the CS content of the environment, predominantly in patients with ANV. This is consistent with the manifestation of multiple CRs.

The effects of ageing on the colonic bacterial microflora in adults.

BACKGROUND The composition of the fecal mircoflora and its changes on ageing have rarely been investigated in large samples of both patients and volunteers. METHODS We analysed the fecal flora by conventional microbiological testing (Kyberstatus, Institute of Microecology, Herborn, Germany) of stool samples from 35 292 adults (age: 46.3 +/- 0.08 [18 to 96] years, 9564 males, 24 784 females; remaining = missing data) with different intestinal and non-intestinal diagnoses for total colony-forming units (CFU) (per g stool) as well as relative abundance of Bifidobacteria, Bacteroides spp., Escherichia coli, Enterococcus spp., and Lactobacillus spp. with respect to age, gender, and clinical data available (e. g., stool consistency and pH). RESULTS The total CFU was stable and showed no age- or gender-related changes. Individual bacterial species constantly and significantly increased with age (E. coli, Enterococci spp.), or decreased at higher age (Bacteroides spp.), or were stable throughout the life span (Lactobacilli, Bifidobacteria). Gastrointestinal diagnoses (Crohns disease, n = 198; ulcerative colitis, n = 515; irritable bowel syndrome, n = 7765; other GI diagnoses, n = 10 478) tended to exhibit some specificity of the bacterial profile, and when GI diagnoses were excluded, the age-related bacterial profile of the remaining group (n = 15 619, m:f = 4197:11 422) was not different. CONCLUSION Conventional microbiological investigations of the fecal microbiota showed both bacteria-specific as well as a general pattern of ageing of the colonic microbiota, with the last decades (more than 60 years) demonstrating the most profound changes. It remains to be shown whether these changes reflect direct changes of the gut microbiota, the mucosal innate immunity, or indirect consequences of age-related altered nutrition.