You will be presented with a collection of medical randomized controlled trial (RCT) reports addressing a shared clinical question -- for instance, the efficacy of a medical intervention on a disease or condition. Given the titles and abstracts of these reports, your task is to generate the conclusion of the systematic review article synthesizing the key findings. Your conclusion should be a few sentences long. In your response, include only the conclusion and no other text. The RCT reports are below.



Title 1:
Availability, fermentability, and energy value of resistant maltodextrin: modeling of short-term indirect calorimetric measurements in healthy adults.
Abstract 1:
BACKGROUND Determination of the metabolizable ( ME ) and net metabolizable ( NME ) energy of total carbohydrate requires estimation of its available ( AC ) and fermentable ( FC ) carbohydrate content . Modeling of indirect calorimetric observations ( respiratory gas exchange ) and breath hydrogen would appear to make it possible to estimate noninvasively these nutritional quantities and the approximate time-course of availability . OBJECTIVE We assessed the time-course of metabolism and energy availability from resistant maltodextrin ( RMD ) by modeling of respiratory gases after a single oral dose . DESIGN Seventeen healthy adults ( 13 M , 4 F ; aged 25 - 46 y ) were r and omly assigned to treatments ( water , maltodextrin , or RMD ) in a multiple-crossover , single-blinded trial with > or = 7 d washout . We monitored 8-h nitrogen-corrected oxygen and carbon dioxide exchanges and breath hydrogen . All treatment groups took low-carbohydrate meals at 3 and 6 h. RESULTS Indirect calorimetry alone provided only qualitative information about the nutritional values of carbohydrate . In contrast , modeling of gaseous exchanges along with the use of central assumptions showed that 17 + /- 2 % of RMD was AC and 40 + /- 4 % was FC . As compared with 17 kJ gross energy/g RMD , mean ( + /- SE ) energy values were 7.3 + /- 0.6 kJ ME/g and 6.3 + /- 0.5 kJ NME/g . The fiber fraction of RMD provided 5.2 + /- 0.7 kJ ME/g and 4.1 + /- 0.6 kJ NME/g . CONCLUSIONS Modeling with the use of this noninvasive and widely available respiratory gas-monitoring technique yields nutritional values for carbohydrate that are supported by enzymatic , microbial , and animal studies and human fecal collection studies . Improvement in this approach is likely and testable across laboratories


Title 2:
Impact of Functional Gastrointestinal Disorders on Survival in the Community
Abstract 2:
OBJECTIVES : Functional gastrointestinal disorders ( FGIDs ) comprise a constellation of symptoms that have no identifiable structural or biochemical abnormality . In view of the lack of data from large-scale population -based studies evaluating the effects of these disorders on survival , we aim ed to examine whether FGIDs are associated with impaired survival . METHODS : Between 1988 and 1993 ,  valid self-report question naires that recorded gastrointestinal symptoms required for the diagnosis of irritable bowel syndrome ( IBS ) , chronic constipation , chronic diarrhea , dyspepsia , and abdominal pain were mailed to r and omly selected cohorts of Olmsted County , Minnesota residents . Minnesota administrative death records were used to identify which of the survey respondents had died over the follow-up period ( through April 2008 ) . The association between survival and each FGID was assessed using proportional hazards regression models with univariate and adjusted hazard ratios ( HRs , 95 % confidence intervals ( CIs ) ) , adjusting for age at time of survey , gender , smoking , alcohol , marital status , and Charlson Comorbidity Index ( CCI ) . RESULTS : Of the 5,262 r and omly selected eligible subjects who received a question naire , a total of 4,176 responded to the surveys ( overall response rate 79 % ) . From these respondents , 243 subjects were excluded because of lack of research authorization ( or were registered solely at a different medical institution in Olmsted County , MN ) , result ing in 3,933 eligible subjects for analysis ( eligible response rate 75 % ) ; 10 % reported symptoms of IBS ; 16 % chronic constipation ; 18 % chronic diarrhea ; 2 % dyspepsia ; and 15 % abdominal pain . At baseline , the mean ( s.d . ) age was 54 ( 18 ) years , and 52 % were female . No association with overall survival was detected for IBS ( HR=1.06 ( 95 % CI : 0.86–1.32 ) ) , chronic diarrhea ( HR=1.03 ( 95 % CI : 0.90–1.19 ) ) , abdominal pain ( HR=1.09 ( 95 % CI : 0.92–1.30 ) ) , or dyspepsia ( HR=1.08 ( 95 % CI : 0.58–2.02 ) ) . Reporting symptoms of chronic constipation was associated with poorer survival ( HR=1.23 ( 95 % CI : 1.07–1.42 ) ) . This association remained significant after adjusting for the CCI ( HR=1.19 ( 95 % CI : 1.03–1.37 ) ) . CONCLUSIONS : In this large population -based cohort study with over 30,000 person-years of follow-up , no significant association was observed between survival and IBS , chronic diarrhea , dyspepsia , or abdominal pain . Furthermore , no association was found between increasing burden of FGIDs and survival . However , in contrast to these other FGIDs , subjects with symptoms of chronic constipation were found to be at increased risk of poorer survival . Further investigation is required to determine the cause of this observed association


Title 3:
The maximum single dose of resistant maltodextrin that does not cause diarrhea in humans.
Abstract 3:
The objective of the present study was to determine the maximum dose of resistant maltodextrin (Fibersol)-2 , a non-viscous water-soluble dietary fiber ) , that does not induce transitory diarrhea . Ten healthy adult subjects ( 5 men and 5 women ) ingested Fibersol-2 at increasing dose levels of 0.7 , 0.8 , 0.9 , 1.0 , and 1.1 g/kg body weight ( bw ) . Each administration was separated from the previous dose by an interval of 1 wk . The highest dose level that did not cause diarrhea in any subject was regarded as the maximum non-effective level for a single dose . The results showed that no subject of either sex experienced diarrhea at dose levels of 0.7 , 0.8 , 0.9 , or 1.0 g/kg bw . At the highest dose level of 1.1 g/kg bw , no female subject experienced diarrhea , whereas 1 male subject developed diarrhea with muddy stools 2 h after ingestion of the test substance . Consequently , the maximum non-effective level for a single dose of the resistant maltodextrin Fibersol-2 is 1.0 g/kg bw for men and > 1.1 g/kg bw for women . Gastrointestinal symptoms were gurgling sounds in 4 subjects ( 7 events ) and flatus in 5 subjects ( 9 events ) , although no association with dose level was observed . These symptoms were mild and transient and resolved without treatment


Title 4:
Digestion-resistant maltodextrin effects on colonic transit time and stool weight: a randomized controlled clinical study
Abstract 4:
Purpose Increased awareness of the importance of dietary fibre has led to increased interest in “ functional ” fibre components like digestion-resistant maltodextrin ( RMD ) . This r and omized , placebo-controlled , double-blind study assessed the effects of RMD in the colonic transit time ( CTT ) and defecation characteristics ( frequency , stool volume and consistency ) . Methods Sixty-six healthy adult volunteers ( 32 men ) who did not have a daily defecation habit had a 7-day run-in period before the 21-day intervention period with RMD or placebo .  CTT and segmental CTT ( SCTT ) were assessed by a single abdominal X-ray film taken at the end of both periods after radiopaque marker ingestion . Defecation characteristics and intestinal functions were also assessed , which were self-reported by patients . Intragroup comparisons were evaluated by Student ’s paired t test , Bonferroni test and Chi-square test , while time comparisons by analysis of variance ( ANOVA ) and time-by-treatment interaction by repeated- measures ANOVA . Results Fifty-seven subjects were assessed for CTT ( placebo , n = 28 ; RMD , n = 29 ) . In the RMD group , the total CTT , left SCTT and rectosigmoidal SCTT decreased significantly compared to baseline ( p < 0.01 each ; −13.3 , −4.7 , −8.7 h , respectively ) . Significant differences between groups were observed in total CTT and left SCTT . Significant time-by-treatment interaction was observed in the RMD group for stool volume ( p = 0.014 ) , increasing 56 % compared to baseline ( p < 0.01 ) , while remained unchanged in the placebo group . Stool consistency was improved only in the RMD group ( p < 0.01 ) . No adverse effects related to study products were observed . Conclusions The results show that RMD improved CTT , stool volume , stool consistency and some intestinal functions in a healthy population


Title 5:
A Novel Resistant Maltodextrin Alters Gastrointestinal Tolerance Factors, Fecal Characteristics, and Fecal Microbiota in Healthy Adult Humans
Abstract 5:
Objective : Resistant maltodextrin has been shown to increase fecal bulk by resisting digestion and being partially fermented by colonic bacteria to short-chain fatty acids ( SCFA ) . The objective of this experiment was to determine potential prebiotic effects , gastrointestinal tolerance , and fecal characteristics of free-living humans fed a novel resistant maltodextrin or a normal maltodextrin control . Methods : Subjects ( n = 38 ) were enrolled in a r and omized , double-blind study where they were assigned to one of three daily treatments : 15 g maltodextrin ; 7.5 g maltodextrin plus 7.5 g resistant maltodextrin ( Fibersol-2 ® ; Matsutani Chemical Company , Hyogo , Japan ) ; and 15 g resistant maltodextrin . The experiment lasted 7 wk and consisted of a 2 wk baseline period , a 3 wk treatment period , and a 2 wk washout period . During wk 3 to 5 ( treatment period ) , subjects consumed their assigned treatments . Results : Resistant maltodextrin supplementation tended to increase ( p = 0.12 ) fecal Bifidobacterium population s during the treatment period , altered ( p < 0.05 ) bacterial population s from baseline to treatment , and result ed in very minor effects in gastrointestinal tolerance . There was a shift ( p < 0.05 ) in molar proportions of SCFA towards butyrate , the preferred energy substrate of colonocytes . Conclusion : Resistant maltodextrin supplementation was well tolerated , result ed in favorable fermentation characteristics in the large bowel , and also result ed in a change in bacterial population


Title 6:
The effect of bran on bowel function in constipation.
Abstract 6:
Bran is widely used to treat a variety of gastrointestinal disorders . With few exceptions , investigative work has focused on the effect of bran in normal subjects . Despite its widespread use , there have been no systematic studies of bran in constipation .  Wheat bran is the " gold st and ard " because no other natural fiber has yet been shown to be as effective in increasing fecal bulk . We evaluated the effect of two brans , wheat and corn ( 20 g/day ) , on fecal weight , fecal moisture content , bowel movement frequency , intestinal transit time , and symptoms in 10 constipated ( less than or equal to 3 movements/wk ) but otherwise healthy women . The administration of bran was associated with a significant increase in fecal weight ( 157 % ) , bowel movement frequency ( 55 % ) , and decrease in intestinal transmit time ( 50 % ) . Percentage fecal moisture increased only with wheat bran ( 67.4 - 72.1 % ) , whereas corn bran was significantly better than wheat bran in relieving symptoms of constipation


Title 7:
COLONIC RESPONSE TO DIETARY FIBRE FROM CARROT, CABBAGE, APPLE, BRAN, AND GUAR GUM
Abstract 7:
Approximately 20 g/day of concentrated dietary fibre from carrot , cabbage , apple , bran , and guar gum was added to the controlled basal diet of nineteen healthy volunteers .  Faecal weight increased by 12 % on bran , 69 % on cabbage , 59 % on carrot , 40 % on apple , and 20 % on guar gum . These changes in faecal weight were correlated with an increased intake of pentose-containing polysaccharides from the fibre . On the basal diet there were pronounced individual differences in faecal weight , and from these the response of subjects to the fibre preparations could be predicted . Addition of fibre shortened mean transit-time through the gut and significantly diluted an inert marker in the faeces . Diet-induced changes in colonic function may explain international differences in the prevalence of colonic disease , whilst personal variation in the response to dietary fibre may determine individual susceptibility to large-bowel disease within a community
As a result of integration analyses , we found that the intake of RMD significantly increased stool volume and stool frequency compared with placebo intake .
Furthermore , RMD intake tended to improve sensation of complete/incomplete evacuation .
In conclusion , the evidence suggests that RMD has a positive effect on bowel movements , contributing to normal bowel function .