MRI assessment on the impact of a low FODMAP diet on the gastrointestinal tract

Introduction: Poorly absorbed fermentable carbohydrates (FODMAPs) escape digestion in the small bowel, and enter the colon to be fermented by gut bacteria thus increasing luminal volume. However, in susceptible individuals e.g. Irritable Bowel Syndrome (IBS) sufferers, this may result in gastrointestinal symptoms, due to the rapid emptying of the small bowel producing increased luminal water and distension in the colon from gas producing bacteria. Previous studies have demonstrated the effect of fermentation on FODMAPs by assessing microbial concentration and breath hydrogen. However, the physiological changes in the lumen, particularly in the colon, remain unclear. Aims: The main purpose of this thesis is to assess the effects of FODMAPs on luminal volume, using magnetic resonance imaging, and how they impact appetite, gastrointestinal symptoms and function. The hypotheses generated and tested were that: i) FODMAPs increase luminal volume, causing symptoms in IBS patients ii) Restriction of FODMAPs reduces luminal volume in patients and healthy volunteers Methods: Four studies were undertaken, with the first being an observational study and the remainder being RCTs. The first study was a pilot study to compare a validated dietary assessment method with a reference method to quantify FODMAP intake in healthy volunteers (n=37). The second study assessed the effect of a low FODMAP diet versus a high FODMAP diet on gastrointestinal physiology and function in healthy volunteers (n=37; FOG). The third study measured the effect of different physical forms of FODMAPs on gastrointestinal physiology in healthy volunteers (n=18; APPLE). The final study compared the effects of a low FODMAP diet versus habitual diet in patients with IBS (n=27; CRAIGS). Results: Findings from the first study suggested that the 7-day food diary is more reliable in assessing energy, nutrient and FODMAP intake within the UK population. In the FOG study, colonic volume increased in both groups and fasting breath hydrogen levels declined on the low FODMAP diet. However, fasting breath hydrogen levels increased in those on a high FODMAP diet when supplemented with oligofructose. In the third study, altering the physical form of a meal had an effect on small bowel water content only during the late phase, whereas gastric emptying in healthy volunteers was fastest with apple juice, followed by apple puree and whole apples respectively. In the CRAIGS study, the low FODMAP diet lowered the increase in colonic volume when compared with the habitual diet. Conclusions: A high FODMAP diet, whether from dietary intake or supplementation, can lead to an increase in colonic volume. In IBS patients this impacts on their overall global symptoms. The unexpected increase with a low FODMAP diet, and the inconclusive effect of fermentation as a result of low breath hydrogen levels, suggests that the role of foods substituted as part of the low FODMAP diet needs further investigation. Meanwhile, altering physical properties of FODMAPs has an impact on luminal volume, but this also needs further investigation. A detailed dietary intake using a 7 day food diary during pre and post dietary intervention is recommended as a measure of compliance

Postinfective bowel dysfunction following Campylobacter enteritis is characterised by reduced microbiota diversity and impaired microbiota recovery

Objectives Persistent bowel dysfunction following gastroenteritis (postinfectious (PI)-BD) is well recognised, but the associated changes in microbiota remain unclear. Our aim was to define these changes after gastroenteritis caused by a single organism, Campylobacter jejuni, examining the dynamic changes in the microbiota and the impact of antibiotics. Design A single-centre cohort study of 155 patients infected with Campylobacter jejuni. Features of the initial illness as well as current bowel symptoms and the intestinal microbiota composition were recorded soon after infection (visit 1, 80 days later (visits 2 and 3). Microbiota were assessed using 16S rRNA sequencing. Results PI-BD was found in 22 of the 99 patients who completed the trial. The cases reported significantly looser stools, with more somatic and gastrointestinal symptoms. Microbiota were assessed in 22 cases who had significantly lower diversity and altered microbiota composition compared with the 44 age-matched and sex-matched controls. Moreover 60 days after infection, cases showed a significantly lower abundance of 23 taxa including phylum Firmicutes, particularly in the order Clostridiales and the family Ruminoccocaceae, increased Proteobacteria abundance and increased levels of Fusobacteria and Gammaproteobacteria. The microbiota changes were linked with diet; higher fibre consumption being associated with lower levels of Gammaproteobacteria. Conclusion The microbiota of PI-BD patients appeared more disturbed by the initial infection compared with the microbiota of those who recovered. The prebiotic effect of high fibre diets may inhibit some of the disturbances seen in PI-BD.Peer reviewe

Processing Apples to Puree or Juice Speeds Gastric Emptying and Reduces Postprandial Intestinal Volumes and Satiety in Healthy Adults

Background: Whole apples produce greater satiety than processed apples, but the underlying mechanisms remain unclear. Objective: Our aim was to assess the intragastric processing of apple preparations and the associated small and large bowel contents using MRI. Methods: An open label , 3-way crossover, randomized, controlled trial. 18 healthy adults [mean ± SD age, 25±4y; BMI(kg/m 2), 22.7±3.5] underwent serial MR scans on 3 occasions separated by 7d, after consumption of isocaloric (178 kcal) portions of either whole apples, apple puree or apple juice. Gastric emptying, small bowel water content (SBWC)(Primary endpoint), were measured at baseline and at 45 minutes intervals (0-270 min) post meal ingestion. Fullness and satiety were also assessed at each time point. Treatment effects between groups were analyzed using ANOVA. Results: Gastric emptying half-time (GE t 50) was greater (P < 0.0001) after participants consumed whole apple (mean ± SEM), 65 (3.3) min) compared with when they consumed apple puree (41(2.8) min) or apple juice (38 (2.9) min), times which did not differ. Postprandial AUC (135-270 min) SBWC was also greater for whole apples than puree (P = 0.025) and juice (P = 0.0004) but juice and puree did not differ. AUC for fullness and satiety (0-270 min) post-ingestion was also greater (P = 0.002 and 0.004 respectively) for whole apple compared to juice but juice and puree did not differ. Conclusions: Gastric emptying is slower after whole apples consumption causing greater sensation of fullness and satiety than puree or juice in healthy adults. Whole apples increased small bowel and colonic contents during the later phase of the study which may be relevant for subsequent food consumption. This study was registered at clinicaltrials.gov as NCT 03714464

Association between knowledge, attitude, and practice of nutrition and food labels among selected higher educational institution students in Klang Valley

Nutrition information on food labels guides consumers to purchase healthier food choices. Besides nutrition information, other factors influence a purchase. This study aims to determine the association between the knowledge, attitude, and practice (KAP) among tertiary students on nutrition and food labels. In this cross-sectional study, a total of 190 students from three tertiary institutions within Klang Valley completed an online survey. Self-administered questionnaires on sociodemographic profiles and KAP questions, available in Malay and English, were distributed. Association between KAP was determined using Spearman's Rho test, while multiple linear regression was used to assess predictors of KAP scores. Mean body mass index (BMI) of the respondents were 20.8 kg/m2. The total mean score for knowledge on food labels was 8.93, followed by attitude and practice with 3.86 and 3.11, respectively. There was a significant correlation between attitude and practice (p<0.005). Nutrient and total calorie information on food labels influenced purchases, with 56.3% of respondents reported looking at the total calorie content, followed by 55.7% and 49.5% checking on sugar and fats, respectively. In addition, other factors such as expiry date (60.9%) and price (59.9%) also influenced purchases. Overall, respondents have a positive attitude on food selection, but male respondents have better knowledge levels than females. However, female respondents interpret food labelling effectively compared to male respondents. Despite having good knowledge and attitude towards nutrition, respondents were still making poor choices. A more extensive range of healthier food options and targeted healthy eating campaigns may empower students to choose more nutritious foods

A low FODMAP diet is associated with changes in the microbiota and reduction in breath hydrogen but not colonic volume in healthy subjects

Background & aims Ingestion of poorly digested, fermentable carbohydrates (fermentable oligo-, di-, mono-saccharides and polyols; FODMAPs) have been implicated in exacerbating intestinal symptoms and the reduction of intake with symptom alleviation. Restricting FODMAP intake is believed to relieve colonic distension by reducing colonic fermentation but this has not been previously directly assessed. We performed a randomised controlled trial comparing the effect of a low FODMAP diet combined with either maltodextrin or oligofructose on colonic contents, metabolites and microbiota. Methods A parallel randomised controlled trial in healthy adults (n = 37). All subjects followed a low FODMAP diet for a week and supplemented their diet with either maltodextrin (MD) or oligofructose (OF) 7g twice daily. Fasted assessments performed pre- and post-diet included MRI to assess colonic volume, breath testing for hydrogen and methane, and stool collection for microbiota analysis. Results The low FODMAP diet was associated with a reduction in Bifidobacterium and breath hydrogen, which was reversed by oligofructose supplementation. The difference in breath hydrogen between groups post-intervention was 27ppm (95% CI 7 to 50, P Conclusion A low FODMAP diet reduces total bacterial count and gas production with little effect on colonic volume.Peer reviewe

MRI assessment on the impact of a low FODMAP diet on the gastrointestinal tract

Introduction: Poorly absorbed fermentable carbohydrates (FODMAPs) escape digestion in the small bowel, and enter the colon to be fermented by gut bacteria thus increasing luminal volume. However, in susceptible individuals e.g. Irritable Bowel Syndrome (IBS) sufferers, this may result in gastrointestinal symptoms, due to the rapid emptying of the small bowel producing increased luminal water and distension in the colon from gas producing bacteria. Previous studies have demonstrated the effect of fermentation on FODMAPs by assessing microbial concentration and breath hydrogen. However, the physiological changes in the lumen, particularly in the colon, remain unclear. Aims: The main purpose of this thesis is to assess the effects of FODMAPs on luminal volume, using magnetic resonance imaging, and how they impact appetite, gastrointestinal symptoms and function. The hypotheses generated and tested were that: i) FODMAPs increase luminal volume, causing symptoms in IBS patients ii) Restriction of FODMAPs reduces luminal volume in patients and healthy volunteers Methods: Four studies were undertaken, with the first being an observational study and the remainder being RCTs. The first study was a pilot study to compare a validated dietary assessment method with a reference method to quantify FODMAP intake in healthy volunteers (n=37). The second study assessed the effect of a low FODMAP diet versus a high FODMAP diet on gastrointestinal physiology and function in healthy volunteers (n=37; FOG). The third study measured the effect of different physical forms of FODMAPs on gastrointestinal physiology in healthy volunteers (n=18; APPLE). The final study compared the effects of a low FODMAP diet versus habitual diet in patients with IBS (n=27; CRAIGS). Results: Findings from the first study suggested that the 7-day food diary is more reliable in assessing energy, nutrient and FODMAP intake within the UK population. In the FOG study, colonic volume increased in both groups and fasting breath hydrogen levels declined on the low FODMAP diet. However, fasting breath hydrogen levels increased in those on a high FODMAP diet when supplemented with oligofructose. In the third study, altering the physical form of a meal had an effect on small bowel water content only during the late phase, whereas gastric emptying in healthy volunteers was fastest with apple juice, followed by apple puree and whole apples respectively. In the CRAIGS study, the low FODMAP diet lowered the increase in colonic volume when compared with the habitual diet. Conclusions: A high FODMAP diet, whether from dietary intake or supplementation, can lead to an increase in colonic volume. In IBS patients this impacts on their overall global symptoms. The unexpected increase with a low FODMAP diet, and the inconclusive effect of fermentation as a result of low breath hydrogen levels, suggests that the role of foods substituted as part of the low FODMAP diet needs further investigation. Meanwhile, altering physical properties of FODMAPs has an impact on luminal volume, but this also needs further investigation. A detailed dietary intake using a 7 day food diary during pre and post dietary intervention is recommended as a measure of compliance

Metabolic Syndrome Screening and Nutritional Status of Patients with Psoriasis: A Scoping Review

Background: Patients with plaque psoriasis have an increased risk of metabolic syndrome. However, no studies have assessed the nutritional status or screening methods of this population. Aims: This review aimed to identify and summarise metabolic syndrome screening criteria and the tools/methods used in nutrition assessment in patients with plaque psoriasis. Data synthesis: PubMed, Web of Science, Ovid and Scopus were searched from inception to March 2023, following the Arkensey and O’Malley framework, to identify articles that report nutritional assessment methods/tools and metabolic screening criteria. Twenty-one studies were identified. Overall, these studies used four different screening criteria to define metabolic syndrome. Patients with psoriasis had a high prevalence of metabolic syndrome and had a poor nutritional status compared to controls. However, only anthropometric measures such as weight, height and waist circumference were employed to determine the nutritional status. Only two studies assessed the vitamin D status. Conclusions: Patients with psoriasis have a poor nutritional status, and they are at risk of nutrient deficiencies. However, these health aspects are not routinely assessed and may increase the risk of malnutrition among these patients. Therefore, additional assessments, such as body composition and dietary assessment, are needed to determine the nutritional status to provide a suitable intervention

Comparison of Cytokine Expression Profile in Chikungunya and Dengue Co-Infected and Mono-Infected Patients’ Samples

Chikungunya (CHIKV) and Dengue (DENV) viruses cause an acute febrile illness which is hard to clinically differentiate and treat since both exhibit similar symptoms. Hence, this study was aimed at identifying the expression profiles of cytokines on co-infected samples and compare with CHIKV and DENV mono-infected samples. Serum samples of 292 suspected patients during 2009–2011 were analyzed. The presence of primary (IgM)/secondary (IgG) antibodies and early NS1 Dengue antigens were confirmed by capture ELISA. Molecular diagnosis and serotypes were discriminated by RT-PCR, confirmed by sequencing. All the plasma samples were assayed for cytokine expression by BDTM cytometry bead array (CBA) and compared with independent mono-infection viral load. Among the tested samples, 82 were confirmed as Dengue positive; 52 through IgM (17.8%), and 30 through IgG (10.2%). Additionally, 186 samples were confirmed as Chikungunya, 96 through IgM (32.6%) and 92 through IgG (31.5%) ELISA, respectively. Interestingly, 19 patients were co-infection positive in which, only 6 were confirmed for CHIKV and 7 for DENV by RT-PCR. Among 8 cytokines, IL-2, IL-8, IFNα, IFN γ, and IL-12 were found to be significantly different between co-infected and CHIKV mono-infected patients and correlated with viral load. DENV viral load was correlated with cytokine expression and a significant difference in IL-2 and IL-12 was observed between DENV mono-infected and DENV and CHIKV co-infected patients. Results indicated that apart from serological and molecular confirmation, cytokines could be used as a specific biomarker for the diagnosis of DENV and CHIKV. In the future, the role of independent cytokines can be determined to understand the pathogenesis and etiology of these dreadful diseases

Comparison of Cytokine Expression Profile in Chikungunya and Dengue Co-Infected and Mono-Infected Patients’ Samples

Chikungunya (CHIKV) and Dengue (DENV) viruses cause an acute febrile illness which is hard to clinically differentiate and treat since both exhibit similar symptoms. Hence, this study was aimed at identifying the expression profiles of cytokines on co-infected samples and compare with CHIKV and DENV mono-infected samples. Serum samples of 292 suspected patients during 2009–2011 were analyzed. The presence of primary (IgM)/secondary (IgG) antibodies and early NS1 Dengue antigens were confirmed by capture ELISA. Molecular diagnosis and serotypes were discriminated by RT-PCR, confirmed by sequencing. All the plasma samples were assayed for cytokine expression by BDTM cytometry bead array (CBA) and compared with independent mono-infection viral load. Among the tested samples, 82 were confirmed as Dengue positive; 52 through IgM (17.8%), and 30 through IgG (10.2%). Additionally, 186 samples were confirmed as Chikungunya, 96 through IgM (32.6%) and 92 through IgG (31.5%) ELISA, respectively. Interestingly, 19 patients were co-infection positive in which, only 6 were confirmed for CHIKV and 7 for DENV by RT-PCR. Among 8 cytokines, IL-2, IL-8, IFNα, IFN γ, and IL-12 were found to be significantly different between co-infected and CHIKV mono-infected patients and correlated with viral load. DENV viral load was correlated with cytokine expression and a significant difference in IL-2 and IL-12 was observed between DENV mono-infected and DENV and CHIKV co-infected patients. Results indicated that apart from serological and molecular confirmation, cytokines could be used as a specific biomarker for the diagnosis of DENV and CHIKV. In the future, the role of independent cytokines can be determined to understand the pathogenesis and etiology of these dreadful diseases