Differing effects of pectin, cellulose and lignin on stool pH, transit time and weight

Randomized cross-over studies were undertaken to determine the effects of daily dietary supplements of pectin (12 g/d), cellulose (15 g/d) and lignin (12 g/d) on stool characteristics of healthy volunteers. Detailed dietary records were kept throughout the study. Stool collections over 48 h were used to determine mean stool pH and weight. The single stool transit time was measured using radio-opaque markers. Pectin did not significantly alter the mean stool pH, transit time or 24 h wet weight. Cellulose lowered the mean stool pH from 6.38 to 6.12, decreased mean stool transit time by 27% and increased mean wet stool weight by 57%. Lignin lowered the mean pH from 6.34 to 6.25, decreased the stool transit time by 20% and increased stool weight by 27% but these changes were not statistically significant. These findings have shown that individual fibre components have different colonic metabolic effects and support the view that associations between dietary fibre intakes and diseases such as colorectal cancer should be evaluated with regard to the type of fibre components consumed.     

Long-term effect of wholemeal bread on stool weight, transit time, fecal bile acids, fats, and neutral sterols

Stool weight, fecal constituents, bile acids, fat, neutral sterols, and intestinal transit time were recorded in 28 subjects over 18 mo. During the first 12 mo the subjects ate white bread. They were studied for an initial period of 7 days, and after 6 mo (study period 1). For the first 6 mo they ate their usual intake of bread, they then increased their white bread intake by 62 g/day for 6 mo (study period 2). The subjects ate a self-selected diet throughout the 18 mo study. During the last 6 mo (study period 3) the subjects replaced white bread by the same amount of wholemeal bread as in study period 2. No increase in stool weight occurred until study period 3 when there was an increase of 20%. There developed a linear relationship between stool weight and intestinal transit time which was not found during the initial first and second study periods. A seasonal influence on serum cholesterol was not observed during the wholemeal bread period. Fecal bile acid excretion was unchanged throughout the experiment.     

Effect of sun-dried raisins on bile acid excretion,intestinal transit time,and fecal weight: a dose-response study

The effect of increasing doses of sun-dried raisins (SDR) on intestinal transit time (TT), fecal weight (FW), and fecal bile acids (FBA) was investigated in 16 healthy adults (6 men and 10 women). In three cycles of 2 weeks each, subjects consumed 84, 126, or 168 g/day of SDR. Four-day fecal collections were performed during the second week of each cycle, and TT, FW, and FBA were measured. FW (mean +/- SEM), increased from 168 +/- 14 g/day without raisins (cycle 1), with a TT of 54 +/- 6 hours, to 200 +/- 24 g/day with 168 g/day raisins (cycle 4), with a TT of 42 +/- 6 hours. Intermediate increases in FW and decreases in TT were observed for cycles 2 and 3. A physiologically meaningful decrease in TT (less than 2 days), to 44 +/- 6 hours, was reached at cycle 2 (not statistically significant). FBA, a possible indicator of colon cancer risk, showed a significant decrease, from 1.00 +/- 0.18 mg/g wet feces at baseline to 0.38 +/- 0.07 mg/g in cycle 2 (P <.005), and remained low in cycles 3 and 4. Major decreases were observed in cycle 2 for fecal lithocholic (P <.02), deoxycholic (P <.002), chenodeoxycholic, and cholic acids, and their concentrations remained low in cycles 3 and 4. Two servings of raisins per day (84 g/day), a relatively small change in diet, can cause beneficial changes in colon function and may decrease the risk for colon cancer.     

Worksite intervention effects on physical health: a randomized controlled trial

Overweight and physical inactivity are risk factors for increased disease burden and health care expenditure. Well-designed studies are still needed to determine the treatment efficacy of worksite interventions targeting such risk factors. This randomized controlled trial was conducted at one of Australia's casinos in 2002-2003, to investigate the effects of a comprehensive exercise and lifestyle intervention on physical fitness. Only 6.4% of the workforce expressed interest in being study participants. Seventy-three employees (aged 32 +/- 8 years, 51% overweight/obese, 73% shift workers and 52% women) were recruited and randomized to treatment or wait-list control groups for 24 weeks, 44 of whom completed the intervention. Components of the intervention include supervised moderate-to-high intensity exercise including combined aerobic (at least 20 min duration 3 days/week) and weight-training (for an estimated 30 min completed 2-3 days/week), and dietary/health education (delivered via group seminars, one-on-one counselling and literature through the provision of a worksite manual). ANCOVA, by intention-to-treat and of study completers, found significant between-group differences in the mean waist circumference and predicted maximal oxygen uptake (VO2max), favouring the intervention, but effects were concentrated in one subject. For study completers, between-group differences in the mean waist circumference (82.3 +/- 9.2 versus 90.5 +/- 17.8 cm, p = 0.01) and predicted VO2max (47 versus 41 ml/kg/min, p < 0.001) remained significant without the outlier, favouring the intervention. Higher intervention compliance predicted greater improvements in physical fitness. No significant effects on body mass or body mass index were found. This worksite intervention significantly improved waist circumference and aerobic fitness in healthy but sedentary employees, most of whom were shift workers. Worksite interventions have the potential to counter the increasing burden of overweight and obesity, particularly visceral adiposity, as well as physical inactivity; however, substantial barriers to adoption/adherence need to be overcome for greater feasibility and impact on employee physical health.     

A novel soy-based meal replacement formula for weight loss among obese individuals: a randomized controlled clinical trial

OBJECTIVE: To assess the efficacy and safety of a low calorie soy-based meal replacement program for the treatment of obesity. DESIGN: A 12-week prospective randomized controlled clinical trial. SETTING: Outpatient weight control research unit. SUBJECTS: One hundred obese (28相似文献   

Plant stanol ester and bran fiber in childhood: effects on lipids, stool weight and stool frequency in preschool children

OBJECTIVES: The objective of the study was to evaluate the effects of plant stanol esters and bran fiber on lipids, stool weight and stool frequency in preschool children. METHODS: The present study was a 13 week open cross-over study designed to evaluate the effects of plant stanol ester in healthy two to five year old preschool children. After a one week lead-in, eligible children were randomly assigned to begin with either Diet Phase A (plant stanol ester) or Phase B (wheat bran fiber). Each diet phase was four weeks long, followed by a two-week wash-out, and then cross-over to the alternate diet. During Diet Phase A children consumed three eight-gram servings of a spread, each containing one gram of plant stanols, for total daily dose of three grams. During Diet Phase B, children added five grams of dietary fiber to their diet for the first two weeks and then ten grams for the second two weeks. RESULTS: Overall, for the whole study group, plant-stanol-ester spread use yielded a decrease in total cholesterol of 19.9 mg/dL (12.4% reduction from baseline) and a 14.6 mg/dL decrease in LDL cholesterol (15.5% reduction from baseline). There were no significant changes in HDL-cholesterol or triglyceride levels. A predominately insoluble dietary fiber supplement derived from wheat bran, as expected, yielded a small but non-significant decrease in total cholesterol of 6.1 mg/dL, a four percent reduction from baseline. CONCLUSIONS: Results demonstrated that preschool age children could adhere to a program requiring consumption of three daily servings of spread containing plant stanol ester and that this level of consumption resulted in a significant decrease in total cholesterol and LDL cholesterol after a four week period. In addition, consumption of plant stanol ester was not associated with any short-term adverse health effects.     

Mean transit time measurement by analysis of a single stool after ingestion of multicolored plastic pellets

Mean transit time (MTT) was measured in 12 females and served as a standard to evaluate the validity of different methods of estimating transit by analysis of a single stool (SST). Each subject consumed three different fiber supplements and a low-fiber control for 14-d periods. On days 4-8 of each period, subjects were given 20 plastic pallets, which varied in color each day. SST was calculated using from two to five sets of colored pellets and different criteria for designation of the stool to be analyzed were compared. Results indicate that the following modifications in the SST method originally proposed by Cummings and Wiggins will result in improved prediction of MTT: 1) Increase the days of dosing from 3 to 6.2) Collect for study the first stool passed 3 h after the last dosing. 3) Include all pellets identified in the selected stool in the SST calculation.     

Placebo effects and the common cold: a randomized controlled trial

PURPOSE We wanted to determine whether the severity and duration of illness caused by the common cold are influenced by randomized assignment to open-label pills, compared with conventional double-blind allocation to active and placebo pills, compared with no pills at all.METHODS We undertook a randomized controlled trial among a population with new-onset common cold. Study participants were allocated to 4 parallel groups: (1) those receiving no pills, (2) those blinded to placebo, (3) those blinded to echinacea, and (4) those given open-label echinacea. Primary outcomes were illness duration and area-under-the-curve global severity. Secondary outcomes included neutrophil count and interleukin 8 levels from nasal wash at intake and 2 days later.RESULTS Of 719 randomized study participants, 2 were lost and 4 exited early. Participants were 64% female, 88% white, and aged 12 to 80 years. Mean illness duration for each group was 7.03 days for those in the no-pill group, 6.87 days for those blinded to placebo, 6.34 days for those blinded to echinacea, and 6.76 days for those in the open-label echinacea group. Mean global severity scores for the 4 groups were no pills, 286; blinded to placebo, 264; blinded to echinacea, 236; and open-label echinacea, 258. Between-group differences were not statistically significant. Comparing the no-pill with blinded to placebo groups, differences (95% confidence interval [CI]) were −0.16 days (95% CI, −0.90 to 0.58 days) for illness duration and −22 severity points (95% CI, −70 to 26 points) for global severity. Comparing the group blinded to echinacea with the open-label echinacea group, differences were 0.42 days (95% CI, −0.28 to 1.12 days) and 22 severity points (95% CI, −19 to 63 points). Median change in interleukin 8 concentration and neutrophil cell count, respectively by group, were 30 pg/mL and 1 cell for the no-pill group, 39 pg/mL and 1 cell for the group binded to placebo, 58 pg/mL and 2 cells for the group blinded to echinacea, and 70 pg/mL and 1 cell for the group with open-label echinacea, also not statistically significant. Among the 120 participants who at intake rated echinacea’s effectiveness as greater than 50 on a 100-point scale for which 100 is extremely effective, illness duration was 2.58 days shorter (95% CI, −4.47 to −0.68 days) in those blinded to placebo rather than no pill, and mean global severity score was 26% lower but not significantly different (−97.0, 95% CI, −249.8 to 55.8 points). In this subgroup, neither duration nor severity differed significantly between the group blinded to echinacea and the open-label echinacea group.CONCLUSIONS Participants randomized to the no-pill group tended to have longer and more severe illnesses than those who received pills. For the subgroup who believed in echinacea and received pills, illnesses were substantively shorter and less severe, regardless of whether the pills contained echinacea. These findings support the general idea that beliefs and feelings about treatments may be important and perhaps should be taken into consideration when making medical decisions.     

Diet-induced weight loss, exercise, and chronic inflammation in older, obese adults: a randomized controlled clinical trial

BACKGROUND: Persistent, low-grade inflammation is an independent predictor of several chronic diseases and all-cause mortality. OBJECTIVE: The intention of this study was to determine the independent and combined effects of diet-induced weight loss and exercise on markers of chronic inflammation. DESIGN: Three hundred sixteen community-dwelling, older (> or = 60 y), overweight or obese [body mass index (in kg/m2) > or = 28], sedentary men and women with radiographic evidence of knee osteoarthritis were randomly assigned to four 18-mo treatments: healthy lifestyle control, diet-induced weight loss, exercise, and diet plus exercise. The exercise intervention consisted of combined weight training and walking for 1 h 3 times/wk. The weight-loss intervention consisted of a weekly session with a registered dietitian to provide education and support for lowering energy intake. RESULTS: The diet-induced weight-loss intervention resulted in significantly greater reductions in concentrations of C-reactive protein (P = 0.01), interleukin 6 (P = 0.009), and soluble tumor necrosis factor alpha receptor 1 (P = 0.007) than did no weight-loss treatment. Changes in soluble tumor necrosis factor alpha receptor 1 but not in C-reactive protein or interleukin 6 correlated with changes in body weight. Exercise training did not have a significant effect on these inflammatory biomarkers, and there was no significant interaction between weight loss and exercise training. CONCLUSIONS: These findings provide evidence from a randomized controlled trial that a dietary intervention designed to elicit weight loss reduces overall inflammation in older, obese persons. Additional studies are needed to assess the effects of different modes and intensities of exercise on inflammation.     

结肠运输试验与排粪造影检查对临床便秘的诊断价值

目的探讨结肠运输试验和排粪造影检查对便秘的诊断价值。方法对86例便秘患者做结肠运输试验及排粪造影检查。结果结肠运输异常者59例,出口梗阻者72例,两者均存在者45例。结论由于结肠运输异常和出口梗阻常合并存在且相互作用,所以结肠运输试验与排粪造影检查联合应用,能够更加准确的鉴别功能性梗阻与结肠运输所致的便秘,为临床治疗提供可靠依据。     

Objectively-assessed physical activity and weight change in young adults: a randomized controlled trial

Background

Reductions in physical activity (PA) are common throughout young adulthood and low PA is associated with weight gain. The SNAP Trial previously reported that two self-regulation approaches to weight gain prevention reduced weight gain over a 2-year period in 18–35 year olds. Presented here are secondary analyses examining changes in PA and the relationship between PA and weight change over 2 years.

Methods

599 young adults (age: 27.4?±?4.4 yrs.; BMI: 25.4?±?2.6 kg/m²) were randomly assigned to 1 of 3 treatment arms: Small Changes (reduce calorie intake by 100 kcals/day & add 2000 steps/day), Large Changes (lose 2.3–4.5 kg initially & increase PA to ≥250 min/wk), or Self-guided (control condition). Small and Large Changes received 10, face-to-face group sessions (months 1–4), and two 4-week refresher courses each subsequent year. Body weight and PA were objectively-measured at baseline, 4 months, 1 and 2 years. Daily steps and bout-related moderate-to-vigorous intensity PA (MVPA: ≥3 METs, ≥10-min bouts) was calculated.

Results

Changes in bout-related MVPA and daily steps did not differ among treatment groups over the 2-year period (p’s?>?0.16). Collapsed across groups, participants gaining >1 lb. (n?=?187; 39.6%) had smaller changes in bout-related MVPA at 4 months, 1 and 2 years relative to those maintaining or losing weight (≤1 lb. weight gain; n?=?282, 60.4%, p’s?<?0.05). Averaged across time points, this difference equated to 47.8 min/week. Those gaining and not gaining >1 lb. did not differ on daily steps (p’s?>?0.10). Among participants engaging in ≥250 min/wk. of MVPA at 2 years (n?=?181), 30% gained >1 lb. from baseline to 2 years, which was not different from those engaging in 150–250 min/wk. (n?=?87; 36%; p?=?0.40), but this percentage was significantly lower when compared to those engaging in <150 min/wk. (n?=?176; 49%; p?<?0.001).

Conclusions

On average, PA differences were not observed between young adults assigned to small or large changes self-regulation interventions to prevent weight gain. Regardless of group assignment, higher levels of MVPA were associated with better weight gain prevention over 2 years. Our data suggest that achieving >150 min/week of MVPA is needed for weight gain prevention and that increasing MVPA, rather than steps, should be targeted.

Trial registration

www.clinicaltrials.gov (NCT01183689). Registered Aug 13, 2010.

     

Double-blind, randomized trial of a synthetic triacylglycerol in formula-fed term infants: effects on stool biochemistry, stool characteristics, and bone mineralization.

BACKGROUND: The low sn-2 palmitate content of infant formulas results in formation of fatty acid calcium soaps in the stools and reduced calcium absorption. OBJECTIVE: Our objective was to test the hypotheses that increasing the proportion of sn-2 palmitate in formula for term infants would result in greater skeletal mineral deposition and reduced stool hardness. DESIGN: Healthy term neonates were randomly assigned to receive standard formula (n = 103) or formula containing 50% sn-2 palmitate (high-sn-2 formula; n = 100) for 12 wk. One hundred twenty breast-fed infants were also studied. The main outcome measures were 1) radial (single-photon absorptiometry) and whole-body (dual-energy X-ray absorptiometry) bone mineral content (WBBMC) at 12 wk and 2) stool frequency, volume, and consistency at 6 and 12 wk. Secondary outcome measures included stool fatty acid content. RESULTS: Infants receiving high-sn-2 formula had higher WBBMC (128.1 +/- 9.7 compared with 122.7 +/- 10.1 g, adjusted for size and sex), softer stools at 6 and 12 wk, and a lower proportion of stool soap fatty acids than did infants receiving the control formula. Breast-fed infants had adjusted WBBMC values (128.3 +/- 9.1 g) similar to those of infants fed high-sn-2 formula and significantly higher than those of infants fed the control formula. CONCLUSIONS: Changing the stereoisomeric structure of palmitate in infant formula resulted in higher WBBMC, reduced stool soap fatty acids, and softer stools more like those of breast-fed infants. The greater bone mass measured could be important if it persists beyond the trial period; this merits further investigation.     

Behavioral self-regulation for weight loss in young adults: a randomized controlled trial

Objective  

To determine the feasibility of recruiting and retaining young adults in a brief behavioral weight loss intervention tailored for this age group, and to assess the preliminary efficacy of an intervention that emphasizes daily self-weighing within the context of a self-regulation model.     

Improving physicians' and nurses' clinical breast examination: a randomized controlled trial

Health professionals' clinical breast examination accuracy and skills are not optimal. We conducted a randomized trial to evaluate changes in physicians' and nurses' lump detection accuracy and examination skills after a training program emphasizing development of tactile skills and using silicone breast models containing lumps of varying sizes, degrees of hardness, and depth of placement. Sensitivity, specificity, and examination technique were measured before and four months after training in 43 experimental group and 46 control group participants. Mean sensitivity increased from 57% to 63% in the experimental group but decreased from 57% to 56% in the control group (P less than or equal to .05). The experimental group's posttest sensitivity was better for each lump characteristic, with statistically significant improvement for the very small (0.3 cm) and medium hard lumps. Duration of examination independently predicted sensitivity. Specificity decreased from 56% to 41% in the experimental group while it increased from 56% to 68% in the control group (P less than or equal to .05). Physicians had significantly higher mean sensitivity than nurses overall, as well as for the larger (1.0 cm), very small (0.3 cm), and softer lumps, but significantly lower mean specificity (33% versus 57%, P = .03). The experimental group improved significantly in five of six technique components while the control group improved in only one. To determine the effect of training on specificity in the clinical setting, we examined medical records of women seen by a subset of experimental and control physicians during the six months following training. There were no significant differences in the proportion of abnormal breast examinations reported or the number of mammograms ordered by experimental and control physicians. Our results show health professionals can be taught successfully to improve their clinical breast examination accuracy and skills.     

Ethical questions on randomized controlled clinical trials

RCT, the new paradigm of modern medicine, was developed in the 40-s of this century and is considered to be the most up-to-date experimental method of our time in comparing the efficacy and value of various prophylactic and therapeutic strategies. Its use, however, poses several ethical questions. The most important of them are: Is this form of experimentation ethical at all? Is it ethically justified to continue the RCT to the stage to reach the statistically significant result between the groups? Is it ethical to assign the patients randomly to the various therapeutic strategies? What is the necessary amount and type of information which is due to the patient? The article endeavours to help to answer these questions.     

Neighborhood effects in a behavioral randomized controlled trial

Randomized controlled trials (RCTs) of interventions intended to modify health behaviors may be influenced by neighborhood effects which can impede unbiased estimation of intervention effects. Examining a RCT designed to increase colorectal cancer (CRC) screening (N=5628), we found statistically significant neighborhood effects: average CRC test use among neighboring study participants was significantly and positively associated with individual patient’s CRC test use. This potentially important spatially-varying covariate has not previously been considered in a RCT. Our results suggest that future RCTs of health behavior interventions should assess potential social interactions between participants, which may cause intervention arm contamination and may bias effect size estimation.     

The effect of indigestible particles on digestive transit time and colonic motility in dogs and pigs

The myoelectric activity of the colon was examined in three dogs and three pigs when they were given a basal diet or a basal diet plus indigestible particles (IP), 2 mm in diameter, at 100 g/kg dry matter. The mean retention time was determined using coloured discs as a marker added to the daily meal. Colonic electromyograms of dogs and pigs given IP revealed a 30% reduction in the number of long spike bursts (LSB) when compared with controls. The other components, propulsive migrating spike bursts (MSB) or non-propulsive short spike bursts (SSB), were unchanged. Mean retention time was decreased from 28.6 h to 17.6 h in dogs and from 129 h to 94.2 h in pigs. These changes developed progressively during 3-4 d in both species, suggesting that the reduction in motor activity was an adaptation to the changes in bulk contents. From the decreased motility of the colon linked to the reduction of LSB and paralleled by an increased transit time, it was concluded that one of the functions of the LSB is to impede the passage of digesta.