Effects of fiber intake on intestinal pH, transit, and predicted oral mesalamine delivery in patients with ulcerative colitis.

BACKGROUND AND AIM: Limited data are available on the effects of fermentable fiber in altering intestinal pH and transit to predict efficacy-based delivery profiles of pH-dependent mesalamine coatings in ulcerative colitis (UC). This study aimed to examine regional pH and transit after acute changes in fermentable fiber intake in quiescent UC patients and their effects on drug release systems. METHODS: In a randomized, double-blind study, 18 patients with quiescent UC and 10 healthy controls were supplied meals high (13 g) or low (≤ 2 g) in fermentable fiber and subsequently ingested a wireless pH-motility capsule. After a ≥ 3-day washout, they crossed over to the other diet. Measurements of intestinal pH and transit were used to predict drug release for the various pH-dependent coatings. RESULTS: Increasing fermentable fiber intake lowered overall (median 6.2 [6.1-6.7] vs low: 6.9 [range or interquartile range: 6.4-7.4]; P = 0.01) and distal pH (7.8 [7.3-8.1] vs 8.2 [8.0-8.5]; P = 0.04) in controls. In UC patients, only cecal pH was decreased (high: 5.1 [4.8-5.5] vs low: 5.5 [5.3-5.7]; P < 0.01). Colonic transit in the UC cohort varied widely after a low-fiber intake but tended to normalize after the high fermentable fiber intake. Hypothetical coating dissolution profiles were heterogeneous in UC patients, with a multi-matrix delayed release system having the highest likelihood of patients (20-40%) with incomplete dissolution, and predominant small intestinal dissolution predicted for Eudragit L (94% patients) and S (44-69%). CONCLUSIONS: Patients with quiescent UC have abnormalities in intestinal pH and transit in response to acute changes in fermentable fiber intake. These have potentially detrimental effects on predicted luminal release patterns of pH-dependent 5-aminosalicylic acid release systems.

How to institute the low-FODMAP diet.

A diet low in poorly absorbed, fermentable, short chain carbohydrates (FODMAPs) is an effective strategy to manage symptoms of irritable bowel syndrome (IBS). The diet has gained traction since its original description in Australia 10 years ago and is now an internationally accepted dietary management strategy for IBS. Randomized controlled trials have raised the profile of the low-FODMAP diet to become a viable first-line therapy for IBS, when implemented under a dietitian's guidance. Importantly, the diagnosis of IBS should be confirmed before commencement of the dietary approach. The skill set of the dietitian is then paramount to the success of the diet. Experience in gastrointestinal disorder management, consideration of symptom types, severity, baseline FODMAP intake, and overall nutritional content and meal pattern are vital in the assessment of the patient. If a strict low-FODMAP diet is deemed necessary, it should only be for an initial period of 4 to 6 weeks. Research suggests that a strict long-term, low-FODMAP diet may negatively impact intestinal microbiome. After the initial strict period, follow up with the dietitian should be conducted to achieve the overall goal-a relaxed FODMAP restriction that enables inclusion of prebiotic FODMAPs while still maintaining symptom relief. The diet will be effective in the vast majority of patients. For those in which it fails, FODMAPs should be reintroduced to the diet, and other dietary (or non-dietary) approaches should be considered.

Poor predictive value of breath hydrogen response for probiotic effects in IBS.

BACKGROUND AND AIMS: Previous observations suggested that an early rise in breath hydrogen after lactulose (ERBHAL) may identify patients with irritable bowel syndrome (IBS) likely to respond to probiotics. Therefore, we aimed to (i) investigate whether treatment with a probiotic changes breath hydrogen response in patients with ERBHAL and (ii) whether these changes identify patients who may benefit symptomatically from probiotics. METHODS: In a randomized, double-blind, placebo-controlled trial, patients with IBS (Rome III) were randomized to either 65 mL/day fermented milk product containing probiotic (FMPP) or placebo for 6 weeks, followed by 6 weeks' open-label treatment and 6 weeks' withdrawal. Breath hydrogen responses to lactulose (15 g) and liquid-gastric emptying time were evaluated before and at the end of each treatment period. Symptoms were measured using a 100-mm visual analog scale. RESULTS: Loss of ERBHAL occurred in 36% of 23 patients receiving FMPP and 41% of 22 receiving placebo (P = 1.00). Amongst 40 patients who completed open-label FMPP treatment, ERBHAL was lost in a further 38%, continued in 25%, and regained in 10%. Similar variability occurred in the withdrawal phase. Variability was unrelated to changes in gastric emptying. No differences in symptom response were seen between treatment groups nor in relation to the loss or retention of ERBHAL. CONCLUSIONS: Breath hydrogen patterns after lactulose are poorly reproducible. No FMPP-specific effects on fermentation patterns or symptoms were observed. The presence of ERBHAL is not useful to predict symptomatic response to probiotic therapy in patients with IBS.

Semiquantitative assessment of breath hydrogen testing.

BACKGROUND AND AIM: A major use of breath hydrogen testing is to assess absorptive capacity for sugars to assist dietary design for management of gut symptoms. Qualitative reporting takes no account of the vigor of hydrogen response and provides little insight into degrees of malabsorption. This study aimed to describe a semiquantitative reporting method and to compare results with those reported qualitatively. METHODS: In consecutive Caucasian patients with Crohn's disease (n = 87), ulcerative colitis (59), functional gastrointestinal disorders (FGID) (162), and healthy controls (76), area under the curve was calculated for lactulose (15 g). This was compared with that for lactose (50 g) and fructose (35 g). Degree of malabsorption was categorized into arbitrary groups. RESULTS: Semiquantitative results for ≥ 30% (designated "convincing") malabsorption was most similar to those using a qualitative cutoff value of 20 ppm, but in 38% and 21% of patients, the classification of malabsorption (nil or clinically significant) changed for fructose and lactose, respectively. Using a cutoff of 10 ppm, 49% and 5% were classified differently. Crohn's disease had a higher prevalence (42%) of convincing fructose malabsorption than controls (24%) or patients with FGID (33%) (P < 0.02). Highest prevalence of convincing lactose malabsorption (38%) was in ulcerative colitis, greater than controls (18%) and FGID (18%) (P < 0.02). CONCLUSIONS: Semiquantitative assessment provides different results with different clinical implications in more than one third of patients, but disease-related alterations in prevalence are similar to those defined qualitatively. This method may be preferable because it lessens the confounding influence of the vigor of the hydrogen response.

Fermentable carbohydrate restriction reduces luminal bifidobacteria and gastrointestinal symptoms in patients with irritable bowel syndrome.

Preliminary studies indicate that dietary restriction of fermentable short-chain carbohydrates improves symptoms in irritable bowel syndrome (IBS). Prebiotic fructo-oligosaccharides and galacto-oligosaccharides stimulate colonic bifidobacteria. However, the effect of restricting fermentable short-chain carbohydrates on the gastrointestinal (GI) microbiota has never been examined. This randomized controlled trial aimed to investigate the effects of fermentable carbohydrate restriction on luminal microbiota, SCFA, and GI symptoms in patients with IBS. Patients with IBS were randomized to the intervention diet or habitual diet for 4 wk. The incidence and severity of symptoms and stool output were recorded for 7 d at baseline and follow-up. A stool sample was collected and analyzed for bacterial groups using fluorescent in situ hybridization. Of 41 patients randomized, 6 were withdrawn. At follow-up, there was lower intake of total short-chain fermentable carbohydrates in the intervention group compared with controls (P = 0.001). The total luminal bacteria at follow-up did not differ between groups; however, there were lower concentrations (P < 0.001) and proportions (P < 0.001) of bifidobacteria in the intervention group compared with controls when adjusted for baseline. In the intention-to-treat analysis, more patients in the intervention group reported adequate control of symptoms (13/19, 68%) compared with controls (5/22, 23%; P = 0.005). This randomized controlled trial demonstrated a reduction in concentration and proportion of luminal bifidobacteria after 4 wk of fermentable carbohydrate restriction. Although the intervention was effective in managing IBS symptoms, the implications of its effect on the GI microbiota are still to be determined.

Fructose and lactose testing.

This article forms part of our 'Tests and results' series for 2012, which aims to provide information about common tests that general practitioners order regularly. It considers areas such as indications, what to tell the patient, what the test can and cannot tell you, and interpretation of results. Functional gut symptoms are a common problem in the community and many patients present to their general practitioner for assessment and guidance.While part of the GP's role is excluding other pathology, helping patients to manage their symptoms is also important.

Gluten causes gastrointestinal symptoms in subjects without celiac disease: a double-blind randomized placebo-controlled trial.

OBJECTIVES: Despite increased prescription of a gluten-free diet for gastrointestinal symptoms in individuals who do not have celiac disease, there is minimal evidence that suggests that gluten is a trigger. The aims of this study were to determine whether gluten ingestion can induce symptoms in non-celiac individuals and to examine the mechanism. METHODS: A double-blind, randomized, placebo-controlled rechallenge trial was undertaken in patients with irritable bowel syndrome in whom celiac disease was excluded and who were symptomatically controlled on a gluten-free diet. Participants received either gluten or placebo in the form of two bread slices plus one muffin per day with a gluten-free diet for up to 6 weeks. Symptoms were evaluated using a visual analog scale and markers of intestinal inflammation, injury, and immune activation were monitored. RESULTS: A total of 34 patients (aged 29-59 years, 4 men) completed the study as per protocol. Overall, 56% had human leukocyte antigen (HLA)-DQ2 and/or HLA-DQ8. Adherence to diet and supplements was very high. Of 19 patients (68%) in the gluten group, 13 reported that symptoms were not adequately controlled compared with 6 of 15 (40%) on placebo (P=0.0001; generalized estimating equation). On a visual analog scale, patients were significantly worse with gluten within 1 week for overall symptoms (P=0.047), pain (P=0.016), bloating (P=0.031), satisfaction with stool consistency (P=0.024), and tiredness (P=0.001). Anti-gliadin antibodies were not induced. There were no significant changes in fecal lactoferrin, levels of celiac antibodies, highly sensitive C-reactive protein, or intestinal permeability. There were no differences in any end point in individuals with or without DQ2/DQ8. CONCLUSIONS: "Non-celiac gluten intolerance" may exist, but no clues to the mechanism were elucidated.

Naturally-occurring dietary salicylates in the genesis of functional gastrointestinal symptoms in patients with irritable bowel syndrome: Pilot study.

BACKGROUND AND AIM: An elimination-rechallenge dietary approach targeting naturally-occurring bioactive chemicals has been proposed to alleviate functional gastrointestinal symptoms. A major focus of this approach is salicylates. This study aimed to address the potential role of dietary salicylates in the induction of symptoms in patients with irritable bowel syndrome (IBS). METHODS: A pilot, double-blind, randomized, cross-over trial of 2-week low- versus high-salicylate diets (6.6 and 27.9 g/day salicylate, respectively) was undertaken. All foods were provided containing minimal quantities of other potential food triggers. Gastrointestinal and extraintestinal symptoms were measured daily using a 100-mm visual-analogue-scale. RESULTS: Ten participants with IBS completed the study, including one with known aspirin-sensitivity. Overall, no differences in symptoms were observed (P = 0.625; Friedman test). However, clear symptom provocation was seen in the aspirin-sensitive participant, with all abdominal symptoms and tiredness worsening during the high-salicylate diet. A similar trend was seen in another participant, where abdominal symptoms gradually worsened during the high-salicylate diet. CONCLUSIONS: These results provide some evidence that food-related salicylates may influence the genesis of symptoms in a subset of patients with IBS. A larger cohort is needed to determine the incidence of salicylate-sensitivity and further evaluate the diet as a potential therapeutic target.The protocol was registered at www.anzctr.org.au (ACTRN12620001250921).

High Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols (FODMAP) Consumption Among Endurance Athletes and Relationship to Gastrointestinal Symptoms.

Endurance athletes commonly experience lower gastrointestinal (GI) symptoms similar to those of irritable bowel syndrome (IBS). Previous research on the restriction of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP), a diet-based mitigation strategy initially developed for IBS, has shown promise for application in athlete populations. Athlete's dietary strategies surrounding exercise have not been formally assessed in relation to FODMAP content of foods or sports nutrition products. Additionally, the FODMAP content of athlete's habitual diets has not been examined in larger sample sizes. This research aims to investigate the FODMAP content of endurance athlete diets by examining these three areas, in conjunction with GI symptoms. Dietary habits surrounding exercise and GI symptoms were examined in 430 endurance athletes using a previously validated Endurance Athlete Questionnaire. A subset of athletes (n = 73) completed a FODMAP-specific food frequency questionnaire for habitual intake. The most commonly reported sports nutrition products were analyzed for FODMAP content using standardized analytical methods. Mean habitual intakes were compared to previous FODMAP studies and medians were compared between those with and without lower GI symptoms. Athletes commonly consumed high FODMAP foods during pre-race dinners and breakfasts, with over 60% reporting specific high FODMAP foods. More frequent nutrition product use, particularly solid, gel/gummy, and homemade products, was often related to increased frequency of GI symptoms. Of the sixteen commonly used sports nutrition products tested, seven were high FODMAP in one serving. All but one of the remaining products became high FODMAP when consumed in multiple servings, as is likely the case during endurance exercise. Average habitual FODMAP intake was 26.1 g (±15.9 g), similar to intakes classified as high FODMAP in previous research on FODMAPs and IBS or GI symptoms. Only 15.1% of athletes consumed a diet that would be considered low in FODMAP. Exploratory analyses showed higher intake of some FODMAP types among athletes exhibiting various lower GI symptoms. Overall, this study demonstrated that FODMAP intake by endurance athletes is high both surrounding exercise and habitually, and may be contributing to GI symptoms experienced during exercise. This information can be utilized when analyzing athlete diets and selecting foods to decrease GI symptoms.

FODMAP project: Development, validation and reproducibility of a short food frequency questionnaire to estimate consumption of fermentable carbohydrates.

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) is a functional disorder that is characterized by gastrointestinal symptoms and that has a major impact on quality of life, resulting in direct and indirect health care costs. The majority of patients with IBS suffer from food intolerances, most commonly related to the consumption of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs). This study aimed to develop and verify the validity and reproducibility of a short food frequency questionnaire (FFQ) to assess typical FODMAP consumption in adults with IBS. METHODS: The primary FFQ list consisted of source foods of FODMAPs that contributed at least 10% to the frequency of consumption among 855 adults from a population-based study in the municipality of Campinas in 2014/2015. In addition, source foods of FODMAPs (according to the Monash University Low FODMAP Diet application) and foods commonly consumed by the Brazilian population (according to the FFQ for adults validated in the city of São Paulo) were included. One hundred and five (n = 105) healthy subjects were recruited to respond to the FFQ twice and to respond the 24-h dietary recall (24HR) three times during a 3-month period. The relative validity of the proposed instrument was compared with the average of the three 24HRs, and the reproducibility of the instrument was assessed by comparing both FFQ applications. The following statistical analyses were used for validation and reproducibility: Wilcoxon's test, Spearman's correlation analysis, weighted kappa, Bland Altman's plot and index, and interclass correlation coefficient. RESULTS: The final list of items for the short FFQ included 54 different foods. The foods were organized by FODMAP groups: free fructose, lactose, total oligosaccharides and total polyols, with variations of categories of responses for consumption frequency between 0 and 10 times and the unit of time in days, weeks or months. In the validity analyses, the correlation coefficients ranged from 0.209 (polyols) to 0.652 (lactose) (p < 0.05). There was no correlation between the methods in the fructose and oligosaccharide groups. The lactose group presented good agreement, and the remaining groups had a lack of agreement, with a mean of 15.7%. The Bland-Altman index values were 4.7% (fructose), 3.8% (lactose), 5.7% (oligosaccharides) and 6.6% (polyols). Regarding reproducibility, the interclass and Spearman's correlation coefficients varied from ICC = 0.781 and r = 0.725 (oligosaccharides) to ICC = 0.913 and r = 0.807 (lactose) (p < 0.05), showing strongly reproducible results for lactose and polyols and good results for fructose and oligosaccharides. Accurate agreement between FFQ applications had a mean of 67.3%, and 3.0% showed disagreement between FFQ1 and FFQ2. The weighted kappa coefficient ranged from 0.576 (polyols) to 0.645 (lactose). CONCLUSION: The semi-quantitative short FFQ was developed to evaluate the consumption of FODMAPs in adults in São Paulo. The instrument presents good reproducibility for all groups of FODMAPs, good validity for lactose and weaker validity for fructose, polyols and oligosaccharides. As the short FFQ was carefully designed for the study population, its estimates are relatively reliable at the population group level. A future reanalysis of this questionnaire would be useful when the chemical composition data of FODMAPs are available.

Manipulation of dietary short chain carbohydrates alters the pattern of gas production and genesis of symptoms in irritable bowel syndrome.

BACKGROUND AND AIM: Reduction of short-chain poorly absorbed carbohydrates (FODMAPs) in the diet reduces symptoms of irritable bowel syndrome (IBS). In the present study, we aimed to compare the patterns of breath hydrogen and methane and symptoms produced in response to diets that differed only in FODMAP content. METHODS: Fifteen healthy subjects and 15 with IBS (Rome III criteria) undertook a single-blind, crossover intervention trial involving consuming provided diets that were either low (9 g/day) or high (50 g/day) in FODMAPs for 2 days. Food and gastrointestinal symptom diaries were kept and breath samples collected hourly over 14 h on day 2 of each diet. RESULTS: Higher levels of breath hydrogen were produced over the entire day with the high FODMAP diet for healthy volunteers (181 +/- 77 ppm.14 h vs 43 +/- 18; mean +/- SD P < 0.0001) and patients with IBS (242 +/- 79 vs 62 +/- 23; P < 0.0001), who had higher levels during each dietary period than the controls (P < 0.05). Breath methane, produced by 10 subjects within each group, was reduced with the high FODMAP intake in healthy subjects (47 +/- 29 vs 109 +/- 77; P = 0.043), but was not different in patients with IBS (126 +/- 153 vs 86 +/- 72). Gastrointestinal symptoms and lethargy were significantly induced by the high FODMAP diet in patients with IBS, while only increased flatus production was reported by healthy volunteers. CONCLUSIONS: Dietary FODMAPs induce prolonged hydrogen production in the intestine that is greater in IBS, influence the amount of methane produced, and induce gastrointestinal and systemic symptoms experienced by patients with IBS. The results offer mechanisms underlying the efficacy of the low FODMAP diet in IBS.

Strategies to manage gastrointestinal symptoms complicating enteral feeding.

Diarrhea and abdominal distension are common complications associated with enteral feeding. Often the cause is unknown, the enteral formula is blamed and changes to the mode of delivery or formula are instituted. However, the evidence base for many strategies used is limited. Altering the osmolality and temperature of the formula and/or the rate of infusion are commonly practiced but evidence for their benefit is largely anecdotal. Preventing microbial contamination of the feed is important and clear guidelines exist to achieve this. The formulation itself can be modified. While the addition of fiber is well supported theoretically, outcome data are less convincing. Avoidance of osmotically active, poorly absorbed short-chain carbohydrates in the formula (often used as the major carbohydrate source) is a new tactic to minimize diarrhea. It has compelling theoretical support, but requires further investigation. A methodical clinical approach to gastrointestinal complications of enteral feeding is warranted and an algorithm for management is proposed.

Low-FODMAP Diet Is Associated With Improved Quality of Life in IBS Patients-A Prospective Observational Study.

BACKGROUND: The low fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) diet is effectively manages irritable bowel syndrome (IBS) symptoms. Long-term low-FODMAP studies rarely report quality of life (QoL). We aimed to determine the effect of low-FODMAP diet on long-term QoL, gastrointestinal (GI) and non-GI symptoms in IBS patients. METHODS: A prospective observational study of IBS patients referred for low-FODMAP dietary advice was performed. The primary outcome of QoL and secondary outcomes of GI symptoms, anxiety/depression, fatigue, sleep quality, and happiness were obtained at baseline, 6 weeks (T6), and 6 months (T26). RESULTS: 111 patients were recruited. 91.0%, 71.6%, and 50.5% of participants completed baseline, T6, and T26 assessments, respectively. There were significant improvements in QoL from baseline at T6 and T26 (both P < 0.001). Significant reductions were seen in GI symptoms at T6 and T26 (both P < 0.001), fatigue at T6 and T26 (both P < 0.003), and anxiety at T6 and T26 (both P < 0.007), compared with baseline. A significant reduction was seen for depression (P < 0.010) from baseline at T26, and a significant increase was seen for both happiness and vitality (both P < 0.04) from baseline at T26. There was a significant correlation between GI symptom response and change in QoL, anxiety, depression, and fatigue (all P < 0.034). CONCLUSION: Low-FODMAP diet was associated with improved long-term QoL and GI symptoms, reduced fatigue and anxiety/depression, and increased happiness and vitality. These data support a wider range of benefits for IBS patients consuming a low-FODMAP diet.

Probiotic effects on intestinal fermentation patterns in patients with irritable bowel syndrome.

AIM: To determine whether Lactobacillus casei strain Shirota (Yakult) can alter small intestinal bacterial overgrowth (SIBO), as tested by the lactulose breath test, and whether this is associated with changes in symptoms in irritable bowel syndrome (IBS). METHODS: 18 patients with IBS (Rome II criteria), who showed an early rise in breath hydrogen with lactulose (ERBHAL), consumed 65 mL of Yakult daily for 6 wk. Lactulose breath test was repeated at the end of the treatment period. Symptoms were recorded daily using a 10 cm visual analogue scale. RESULTS: 14 patients completed the study, 9 (64%) had reversal of ERBHAL, with the median time of first rise in breath hydrogen increasing from 45 to 75 min (P = 0.03). There was no significant improvement in the symptom score with probiotic therapy, except for wind (P = 0.04). Patients commencing with at least moderate symptoms and who no longer had ERBHAL at the end of treatment, showed improvement in the overall symptoms scores [median final score 5.3 (IQR 3.9-5.9), 55% reduction; n = 6] to a greater extent than those who had had persisting ERBHAL [final score 6.9 (5.0-7.0), 12% reduction; n = 5; P = 0.18]. CONCLUSION: Yakult is effective in altering fermentation patterns in the small bowel, consistent with reducing SIBO. The loss of ERBHAL was associated with reduced symptoms. The true interpretation of these findings awaits a randomised, controlled trial.

Randomised clinical trial: reducing the intake of dietary FODMAPs of breastfeeding mothers is associated with a greater improvement of the symptoms of infantile colic than for a typical diet.

BACKGROUND: Therapeutic diets for infantile colic lack evidence. In breastfed infants, avoiding "windy" foods by the breastfeeding mother is common. AIM: To examine the effects of a maternal low-FODMAP (Fermentable, Oligosaccharides, Disaccharides, Monosaccharides, And Polyols) diet compared to a typical-Australian diet on infant crying-fussing durations of infants with colic in a randomised, double-blind, crossover feeding study. METHODS: Between 2014 and 2016 exclusively breastfed infants aged ≤9 weeks meeting Wessel criteria for colic were recruited. Mothers were provided a 10-day low-FODMAP or typical-Australian diet, then alternated without washout. Infants without colic (controls) were observed prospectively and mothers remained on habitual diet. Infant crying-fussing durations were captured using a Barr Diary. Measures of maternal psychological status and samples of breast milk and infant faeces were collected. RESULTS: Mean crying-fussing durations were 91 min/d in seven controls compared with 269 min/d in 13 colicky infants (P < 0.0001), which fell by median 32% during the low-FODMAP diet compared with 20% during the typical-Australian diet (P = 0.03), confirmed by a two-way mixed-model analyses-of-variance (ƞp 2  = 0.719; P = 0.049) with no order effect. In breast milk, lactose concentrations remained stable and other known dietary FODMAPs were not detected. Changes in infant faecal calprotectin were similar between diets and groups, and faecal pH did not change. Median maternal anxiety and stress fell with the typical-Australian diet (P < 0.01), but remained stable on the low-FODMAP diet. CONCLUSIONS: Maternal low-FODMAP diet was associated with enhanced reduction in crying-fussing durations of infants with colic. This was not related to changes in maternal psychological status, gross changes in breast milk or infant faeces. Mechanisms require elucidation. Trial Registration Australian New Zealand Clinical Trials Registry (ANZCTR): 12616000512426 - anzctr.org.au.

Fructan and free fructose content of common Australian vegetables and fruit.

Fructans are not digested in the small intestines of humans. While many health benefits have been attributed to these carbohydrates, they can cause gastrointestinal symptoms in some individuals. We measured the total fructans in 60 vegetables and 43 fruits using the Megazyme fructan assay. Vegetables with the highest quantity of fructans included garlic, artichoke, shallots, leek bulb, and onions (range, 1.2-17.4 g/100 g fw). Fruits with low, but detectable, fructans included longon, white peach, persimmon, and melon (range, 0.21-0.46 g/100 g fw). The fructan assay was modified to provide an estimate of the average chain length (degree of polymerization) for high fructan vegetables. d-Fructose can also be malabsorbed in the small intestine of humans, so the d-fructose content in some foods was measured to supplement the current food tables. Research in this area will be facilitated through the availability of more comprehensive food composition data.

Poor reproducibility of breath hydrogen testing: Implications for its application in functional bowel disorders.

BACKGROUND: Limited data are available regarding the reproducibility of lactulose and fructose breath testing for clinical application in functional bowel disorders. OBJECTIVES: The purpose of this study was to investigate the reproducibility of lactulose and fructose breath hydrogen testing and assess symptom response to fructose testing. METHODS: Results were analysed from 21 patients with functional bowel disorder with lactulose breath tests and 30 with fructose breath tests who completed another test >2 weeks later. Oro-caecal transit time, hydrogen responses, both qualitatively (positive/negative) and quantitatively (area under the curve (AUC) for hydrogen), were compared between tests. In another 36 patients, data scores for overall abdominal symptoms, abdominal pain, bloating, wind, nausea and fatigue were collected during the fructose test and compared to hydrogen responses. RESULTS: No correlations were found for lactulose AUC (linear regression, p = 0.58) or transit time (Spearman's p = 0.54) between tests. A significant proportion (30%) lost the presence of fructose malabsorption (p < 0.01). Hydrogen AUC for fructose did not correlate between tests, (r = 0.28, p = 0.17) independent of time between testing (p = 0.82). Whilst patients with fructose malabsorption were more likely to report symptoms than those without (56% vs 17%; p = 0.04), changes in symptom severity were not different (p > 0.05). CONCLUSIONS: Routine use of lactulose and fructose breath tests in functional bowel disorder patients is not supported due to its poor reproducibility and low predictive value for symptom responses.

Management Strategies for Abdominal Bloating and Distension.

Bloating and distension are among the most common gastrointestinal complaints reported by patients with functional gut disorders and by the general population. These 2 complaints are also among the most prevalent of the severe symptoms reported by patients with irritable bowel syndrome. Nonetheless, only a limited number of published studies have specifically addressed bloating; it is infrequently studied as a primary endpoint, and what little systematic information exists has often been garnered from the assessment of secondary endpoints or the dissection of composite endpoints. This lack of data, and our consequent limited understanding of the pathophysiology of bloating, had hampered the quest for effective and targeted therapies until recently. Advances in the knowledge of underlying mechanisms, particularly with regard to the roles of diet, poorly absorbed fermentable carbohydrates, dysbiosis of the gut bacteria, alterations in visceral hypersensitivity, and abnormal viscerosomatic reflexes, have enabled the development of improved treatment options. The most significant recent advance has been a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, which significantly reduces patients' symptoms and improves quality of life. Given the prevalence of bloating and its perceived severity, it is clear that further studies regarding the pathogenesis and treatment of this problem are needed.

Fermentable oligosaccharides, disaccharides, monosaccharides and polyols: role in irritable bowel syndrome.

Irritable bowel syndrome (IBS) was previously left poorly treated despite its high prevalence and cost. Over the past decade, significant research has been conducted providing new dietary strategies for IBS management. The 'low fermentable oligosaccharides, disaccharides, monosaccharides and polyols diet' has shown symptom improvement in 68-76% of patients. Randomized, controlled trials have now proven its efficacy. The diet, low in poorly absorbed and fermentable carbohydrates, uses dietary restriction and re-challenge to determine individual tolerance to various short-chain carbohydrates. However there may be potential detrimental effects of the diet in the long term, due to potential changes to the gastrointestinal microbiota. Appropriate dietary education and management of the diet is imperative. Future research should focus on the relevance of changes to the microbiota and ways to liberalize the dietary restrictions.