Case Study: Utilizing a Low FODMAP Diet to Combat Exercise-Induced Gastrointestinal Symptoms

Athletes employ various dietary strategies in attempts to attenuate exercise-induced gastrointestinal (GI) symptoms to ensure optimal performance. This case-study outlines one of these GI-targeted approaches via the implementation of a short-term low FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols) diet, with the aim to attenuate persistent running specific GI symptoms in a recreationally competitive multisport athlete (male, 86 kg, 57.9 ml·kg·min-1 V02max, 10–15 hr/week training, with no diagnosed GI disorder). Using a single-blinded approach a habitual diet was compared with a 6-day low FODMAP intervention diet (81 ± 5g vs 7.2 ± 5.7g FODMAP s/day) for their effect on GI symptoms and perceptual wellbeing. Training was similar during the habitual and dietary intervention periods. Postexercise (During) GI symptom ratings were recorded immediately following training. Daily GI symptoms and the Daily Analysis of Life Demands for Athletes (DALDA) were recorded at the end of each day. Daily and During GI symptom scores (scale 0–9) ranged from 0–4 during the habitual dietary period while during the low FODMAP dietary period all scores were 0 (no symptoms at all). DALDA scores for worse than normal ranged from 3–10 vs 0–8 in the habitual and low FODMAP dietary periods, respectively, indicating improvement. This intervention was effective for this GI symptom prone athlete; however, randomized-controlled trials are required to assess the suitability of low FODMAP diets for reducing GI distress in other symptomatic athletes.

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Applying a Low-FODMAP Dietary Intervention to a Female Ultraendurance Runner With Irritable Bowel Syndrome During a Multistage Ultramarathon

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.2017-0398 ◽

2019 ◽

Vol 29 (1) ◽

pp. 61-67 ◽

Cited By ~ 5

Author(s):

Stephanie K. Gaskell ◽

Ricardo J.S. Costa

Keyword(s):

Irritable Bowel Syndrome ◽

Dietary Intervention ◽

Gastrointestinal Symptoms ◽

Irritable Bowel Syndrome Symptom ◽

Carbohydrate Intake ◽

Severe Nausea ◽

Dietary Analysis ◽

Irritable Bowel ◽

Fodmap Diet ◽

The Impact

Malabsorption of fermentable oligo-, di-, mono-saccharides and polyols (FODMAPs) in response to prolonged exercise may increase incidence of upper and lower gastrointestinal symptoms (GIS), which are known to impair exercise performance. This case study aimed to explore the impact of a low-FODMAP diet on exercise-associated GIS in a female ultraendurance runner diagnosed with irritable bowel syndrome, competing in a 6-day 186.7-km mountainous multistage ultramarathon (MSUM). Irritable bowel syndrome symptom severity score at diagnosis was 410 and following a low-FODMAP diet (3.9 g FODMAPs/day) it reduced to 70. The diet was applied 6 days before (i.e., lead-in diet), and maintained during (5.1 g FODMAPs/day) the MSUM. Nutrition intake was analyzed through dietary analysis software. A validated 100-mm visual analog scale quantified GIS incidence and severity. GIS were modest during the MSUM (overall mean ± SD: bloating 27 ± 5 mm and flatulence 23 ± 8 mm), except severe nausea (67 ± 14 mm) experienced throughout. Total daily energy (11.7 ± 1.6 MJ/day) intake did not meet estimated energy requirements (range: 13.9–17.9 MJ/day). Total daily protein [1.4 ± 0.3 g·kg body weight (BW)−1·day−1], carbohydrate (9.1 ± 1.3 g·kg BW−1·day−1), fat (1.1 ± 0.2 g·kg BW−1·day−1), and water (78.7 ± 6.4 ml·kg BW−1·day−1) intakes satisfied current consensus guidelines, except for carbohydrates. Carbohydrate intake during running failed to meet recommendations (43 ± 9 g/hr). The runner successfully implemented a low-FODMAP diet and completed the MSUM with minimal GIS. However, suboptimal energy and carbohydrate intake occurred, potentially exacerbated by nausea associated with running at altitude.

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Low FODMAP Diet Is Not Effective in Children with Functional Abdominal Pain: A Randomized Controlled Trial

Annals of Nutrition and Metabolism ◽

10.1159/000510795 ◽

2020 ◽

Vol 76 (5) ◽

pp. 334-344

Author(s):

Katarzyna Mirosława Boradyn ◽

Katarzyna Eufemia Przybyłowicz ◽

Elżbieta Jarocka-Cyrta

Keyword(s):

Abdominal Pain ◽

Dietary Intervention ◽

Rating Scale ◽

Controlled Trial ◽

Statistical Significance ◽

Gastrointestinal Symptoms ◽

Stool Consistency ◽

Functional Abdominal Pain ◽

Abdominal Symptoms ◽

Fodmap Diet

Introduction: A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) has been shown to reduce symptoms among adult patients and children with irritable bowel syndrome. There are no studies investigating the effectiveness of the low FODMAP diet in pediatric patients with functional abdominal pain (FAP). Objective: The study aimed to evaluate the effectiveness of the low FODMAP diet in reducing gastrointestinal symptoms in children with FAP in comparison to the control diet based on the National Institute for Health and Care Excellence (NICE) guidelines. Methods: Twenty-seven children with diagnosed FAP were randomized to 2 groups. Each group received an intervention: the low FODMAP diet or the diet based on NICE. All food was prepared and delivered by a catering company. Data regarding gastrointestinal symptoms were recorded by participants during the 2-week baseline assessment and 4-week dietary intervention. The frequencies of abdominal pain and stools were reported as a number of events per day. The severity of abdominal pain was assessed using the Wong-Baker FACES Pain Rating Scale. The assessment of stool consistency was based on the Bristol Stool Form Scale. Results: The tendency toward the improvement in abdominal symptoms was noted in the low FODMAP group but without statistical significance. No significant differences in stool consistency were observed in this group. The NICE group experienced significant reduction in abdominal pain intensity and frequency (p < 0.01) and improvement in stool consistency (93% reporting normal stool, p < 0.05). Conclusions: The results of this pilot study suggest that the low FODMAP diet is not effective in the reduction of symptoms in children with FAP.

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Parental Opinion about the Low FODMAP Diet in Dietary Treatment of Children with Functional Abdominal Pain

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17155554 ◽

2020 ◽

Vol 17 (15) ◽

pp. 5554

Author(s):

Katarzyna Mirosława Boradyn ◽

Elżbieta Jarocka-Cyrta ◽

Katarzyna Eufemia Przybyłowicz ◽

Małgorzata Obara-Gołębiowska

Keyword(s):

Abdominal Pain ◽

Dietary Intervention ◽

Gastrointestinal Symptoms ◽

Dietary Treatment ◽

Lower Percentage ◽

Functional Abdominal Pain ◽

Self Assessment ◽

Nice Guidelines ◽

Parental Opinion ◽

Fodmap Diet

The aim of this study was primarily to evaluate differences between parental opinion about the diet and overall changes in children’s symptoms of functional abdominal pain (FAP) during the low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet and National Institute for Health and Care Excellence (NICE) diet. Secondly, this paper examined the agreement between parental perception of children’s symptoms and children’s self-assessment of symptoms during the diet in both treatment groups. Twenty-seven children with diagnosed functional abdominal pain (FAP) were randomized to one of two group, receiving the low FODMAP diet or the diet based on NICE guidelines. Children reported gastrointestinal symptoms at baseline and during the diet. At the end of the intervention, parents assessed their children’s diet and symptoms changes, using Likert scales. The agreement between parental and children assessments of gastrointestinal symptoms was defined as the percentage of compatible answers. In the low FODMAP group a significantly lower percentage of parents (38%) declared that it was easy to follow the diet, compared to the NICE group (57%), (p = 0.017). A high percentage of parents in both groups reported improvement in all symptoms of children during dietary intervention. A high level of agreement was also observed between parental and children’s self-assessment of abdominal pain intensity and frequency. Our research suggests that in parental opinion the low FODMAP diet is as effective as the diet based on NICE guidelines in children with FAP. However, the low FODMAP diet may seem more difficult to follow, and this may have had an impact on the effectiveness and acceptability of the FODMAP diet by children.

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

Frontiers in Nutrition ◽

10.3389/fnut.2021.637160 ◽

2021 ◽

Vol 8 ◽

Author(s):

Lauren A. Killian ◽

Jane G. Muir ◽

Jacqueline S. Barrett ◽

Nicholas A. Burd ◽

Soo-Yeun Lee

Keyword(s):

Dietary Habits ◽

Endurance Athlete ◽

Gastrointestinal Symptoms ◽

Sports Nutrition ◽

Endurance Athletes ◽

Gi Symptoms ◽

Irritable Bowel ◽

Habitual Intake ◽

Dietary Strategies ◽

Specific Food

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.

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Dietary practices of women with Endometriosis: a cross-sectional survey

10.21203/rs.3.rs-244673/v1 ◽

2021 ◽

Author(s):

Mike Armour ◽

Alexandra Middleton ◽

Siew Lim ◽

Justin Sinclair ◽

David Varjabedian ◽

...

Keyword(s):

Online Survey ◽

Management Strategies ◽

Gastrointestinal Symptoms ◽

Community Setting ◽

Self Management ◽

Cross Sectional Survey ◽

Dietary Practices ◽

Cross Sectional ◽

Fodmap Diet ◽

Dietary Strategies

Abstract Background: Endometriosis causes deleterious effects on the lives of sufferers across multiple domains impacting quality of life. Commonly utilised pharmaceutical interventions offer sub-optimal efficacy in addition to potentially intolerable side effects for many women. There is some evidence for dietary therapies reducing endometriosis symptoms but little data on dietary preferences / strategies used, and their impact, in a community setting. Methods: A cross-sectional online survey was conducted between October and December 2017 to investigate the self-management strategies employed by women with endometriosis. Participants were aged 18-45 years, living in Australia and had a surgically confirmed diagnosis of endometriosis. Results: Four hundred and eighty-four responses were included for analysis, with 76% of women reporting the use of general self-management strategies within the last six months. Of these, 44% of respondents reported using dietary strategies for symptom management. Reducing or eliminating gluten, reducing or eliminating dairy and the low FODMAP diet were the most commonly reported dietary strategies utilised. Respondents reported a 6.4/10 effectiveness score for reduction in pelvic pain with dietary changes, with no difference in pain reduction between the various diets used. Further, women self-reported significant improvements in co-morbidities such as gastrointestinal disturbance (39%), nausea and vomiting (15%) and fatigue (15%).Conclusions: Dietary modifications are a very common self-management strategy employed by people with endometriosis, with the greatest benefit reported on gastrointestinal symptoms. Reducing or eliminating gluten, dairy or FODMAPs, or a combination of these, were the most common strategies. No single diet appeared to provide greater self-reported benefits than others.

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Diarrhea Predominant-Irritable Bowel Syndrome (IBS-D): Effects of Different Nutritional Patterns on Intestinal Dysbiosis and Symptoms

Nutrients ◽

10.3390/nu13051506 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1506

Author(s):

Annamaria Altomare ◽

Claudia Di Rosa ◽

Elena Imperia ◽

Sara Emerenziani ◽

Michele Cicala ◽

...

Keyword(s):

Irritable Bowel Syndrome ◽

Intestinal Microbiota ◽

Gastrointestinal Disorder ◽

Additional Energy ◽

Nutritional Advice ◽

Intestinal Dysbiosis ◽

Gi Symptoms ◽

Mutualistic Relationship ◽

Irritable Bowel ◽

Fodmap Diet

Irritable Bowel Syndrome (IBS) is a chronic functional gastrointestinal disorder characterized by abdominal pain associated with defecation or a change in bowel habits. Gut microbiota, which acts as a real organ with well-defined functions, is in a mutualistic relationship with the host, harvesting additional energy and nutrients from the diet and protecting the host from pathogens; specific alterations in its composition seem to play a crucial role in IBS pathophysiology. It is well known that diet can significantly modulate the intestinal microbiota profile but it is less known how different nutritional approach effective in IBS patients, such as the low-FODMAP diet, could be responsible of intestinal microbiota changes, thus influencing the presence of gastrointestinal (GI) symptoms. The aim of this review was to explore the effects of different nutritional protocols (e.g., traditional nutritional advice, low-FODMAP diet, gluten-free diet, etc.) on IBS-D symptoms and on intestinal microbiota variations in both IBS-D patients and healthy subjects. To date, an ideal nutritional protocol does not exist for IBS-D patients but it seems crucial to consider the effect of the different nutritional approaches on the intestinal microbiota composition to better define an efficient strategy to manage this functional disorder.

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Relationship of Carbohydrate Intake during a Single-Stage One-Day Ultra-Trail Race with Fatigue Outcomes and Gastrointestinal Problems: A Systematic Review

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18115737 ◽

2021 ◽

Vol 18 (11) ◽

pp. 5737

Author(s):

Soledad Arribalzaga ◽

Aitor Viribay ◽

Julio Calleja-González ◽

Diego Fernández-Lázaro ◽

Arkaitz Castañeda-Babarro ◽

...

Keyword(s):

Systematic Review ◽

Single Stage ◽

Cochrane Library ◽

Exercise Recovery ◽

Post Exercise ◽

Exercise Load ◽

Gi Symptoms ◽

Gastrointestinal Problems ◽

Exercise Induced ◽

Post Exercise Recovery

Due to the high metabolic and physical demands in single-stage one-day ultra-trail (SOUT) races, athletes should be properly prepared in both physical and nutritional aspects in order to delay fatigue and avoid associated difficulties. However, high carbohydrate (CHO) intake would seem to increase gastrointestinal (GI) problems. The main purpose of this systematic review was to evaluate CHO intake during SOUT events as well as its relationship with fatigue (in terms of internal exercise load, exercise-induced muscle damage (EIMD) and post-exercise recovery) and GI problems. A structured search was carried out in accordance with PRISMA guidelines in the following: Web of Science, Cochrane Library and Scopus databases up to 16 March 2021. After conducting the search and applying the inclusion/exclusion criteria, eight articles in total were included in this systematic review, in all of which CHO intake involved gels, energy bars and sports drinks. Two studies associated higher CHO consumption (120 g/h) with an improvement in internal exercise load. Likewise, these studies observed that SOUT runners whose intake was 120 g/h could benefit by limiting the EIMD observed by CK (creatine kinase), LDH (lactate dehydrogenase) and GOT (aspartate aminotransferase), and also improve recovery of high intensity running capacity 24 h after a trail marathon. In six studies, athletes had GI symptoms between 65–82%. In summary, most of the runners did not meet CHO intake standard recommendations for SOUT events (90 g/h), while athletes who consumed more CHO experienced a reduction in internal exercise load, limited EIMD and improvement in post-exercise recovery. Conversely, the GI symptoms were recurrent in SOUT athletes depending on altitude, environmental conditions and running speed. Therefore, a high CHO intake during SOUT events is important to delay fatigue and avoid GI complications, and to ensure high intake, it is necessary to implement intestinal training protocols.

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Characteristics of Opioid Prescriptions to Veterans With Chronic Gastrointestinal Symptoms and Disorders Dually Enrolled in the Department of Veterans Affairs and Medicare Part D

Military Medicine ◽

10.1093/milmed/usab095 ◽

2021 ◽

Author(s):

Salva N Balbale ◽

Lishan Cao ◽

Itishree Trivedi ◽

Jonah J Stulberg ◽

Katie J Suda ◽

...

Keyword(s):

Gastrointestinal Symptoms ◽

Medicare Part D ◽

Medicare Part ◽

Opioid Use ◽

Opioid Prescription ◽

Part D ◽

Gi Symptoms ◽

Chronic Opioid Use ◽

Multiple Logistic Regression Modeling ◽

Chronic Use

ABSTRACT Introduction Gastrointestinal (GI) symptoms and disorders affect an increasingly large group of veterans. Opioid use may be rising in this population, but this is concerning from a patient safety perspective, given the risk of dependence and lack of evidence supporting opioid use to manage chronic pain. We examined the characteristics of opioid prescriptions and factors associated with chronic opioid use among chronic GI patients dually enrolled in the DVA and Medicare Part D. Materials and Methods In this retrospective cohort study, we used linked, national patient-level data (from April 1, 2011, to December 31, 2014) from the VA and Centers for Medicare & Medicaid Services to identify chronic GI patients and observe opioid use. Veterans who had a chronic GI symptom or disorder were dually enrolled in VA and Part D and received ≥1 opioid prescription dispensed through the VA, Part D, or both. Chronic GI symptoms and disorders included chronic abdominal pain, chronic pancreatitis, inflammatory bowel diseases, and functional GI disorders. Key outcome measures were outpatient opioid prescription dispensing overall and chronic opioid use, defined as ≥90 consecutive days of opioid receipt over 12 months. We described patient characteristics and opioid use measures using descriptive statistics. Using multiple logistic regression modeling, we generated adjusted odds ratios and 95% CIs to determine variables independently associated with chronic opioid use. The final model included variables outlined in the literature and our conceptual framework. Results We identified 141,805 veterans who had a chronic GI symptom or disorder, were dually enrolled in VA and Part D, and received ≥1 opioid prescription dispensed from the VA, Part D, or both. Twenty-six percent received opioids from the VA only, 69% received opioids from Medicare Part D only, and 5% were “dual users,” receiving opioids through both VA and Part D. Compared to veterans who received opioids from the VA or Part D only, dual users had a greater likelihood of potentially unsafe opioid use outcomes, including greater number of days on opioids, higher daily doses, and higher odds of chronic use. Conclusions Chronic GI patients in the VA may be frequent users of opioids and may have a unique set of risk factors for unsafe opioid use. Careful monitoring of opioid use among chronic GI patients may help to begin risk stratifying this group. and develop tailored approaches to minimize chronic use. The findings underscore potential nuances within the opioid epidemic and suggest that components of the VA’s Opioid Safety Initiative may need to be adapted around veterans at a higher risk of opioid-related adverse events.

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619 HIGH DISCOVERY RATE OF GASTRODUODENAL EOSINOPHILIA BUT NOT EOSINOPHILIC ESOPHAGITIS IN PATIENTS WITH CHRONIC GASTROINTESTINAL SYMPTOMS

Diseases of the Esophagus ◽

10.1093/dote/doab052.619 ◽

2021 ◽

Vol 34 (Supplement_1) ◽

Author(s):

Nicholas Talley ◽

Amol Kamboj ◽

William Chey ◽

Henrik Rasmussen ◽

Brian Lacy ◽

...

Keyword(s):

Eosinophilic Esophagitis ◽

Gastrointestinal Symptoms ◽

High Rate ◽

Systematic Evaluation ◽

Tissue Eosinophilia ◽

Severity Scores ◽

Gi Symptoms ◽

Multi Center Study ◽

Loss Of Appetite ◽

Duodenal Biopsies

Abstract Although the prevalence of eosinophilic gastrointestinal disorders (EGIDs) is increasing, there is evidence that eosinophilic gastritis and/or duodenitis (EG/EoD) are underdiagnosed. Patients with EG/EoD often present with chronic, non-specific gastrointestinal (GI) symptoms, similar to patients with functional GI disorders. We hypothesized that systematic evaluation, including multiple esophageal, gastric and duodenal biopsies, of patients with chronic GI symptoms might reveal a high rate of gastroduodenal eosinophila, with or without eosinophilic esophagitis (EoE). Methods We performed a prospective multi-center study of patients with non-specific GI symptoms for ≥6 months, from 20 sites. Patients completed a questionnaire assessing abdominal pain, abdominal cramping, early satiety, bloating, nausea, vomiting, diarrhea, and loss of appetite. Those with daily average symptom severity scores ≥3/10 for any single symptom underwent esophagogastroduodenoscopy (EGD) with collection of 4 esophageal (EoE), 8 gastric, and 4 duodenal biopsies, analyzed by central pathologists. Histologic criteria for EoE was ≥15eos/hpf in ≥1 esophageal site and for EG/EoD was peak eosinophil counts ≥30/hpf in ≥5 gastric hpfs and/or 3 duodenal hpfs—criteria used in randomized trials. Results Of 556 patients screened, 405 (73%) met symptom criteria and underwent EGD; 181 patients (45%, mean age 45, 73% female) who underwent EGD met the histologic criteria for EG/EoD, and of these, 7% also had EoE diagnosed. Overall 2% met histologic criteria for EoE alone. Of patients who met the histologic criteria for EG/EoD, 93% were previously diagnosed with gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), or functional dyspepsia (FD) (Figure 1). The average duration of GI symptoms in the screened population as well as those that met histologic criteria for EG/EoD was 11 years. Conclusion Forty-five percent of patients with moderate-to-severe GI symptoms who underwent EGD met histologic criteria for EG/EoD. Over 90% of these patients had previously been diagnosed with GERD, IBS, and/or FD, and had minimal overlap with EoE. EGD with systematic gastroduodenal biopsies, and intentional evaluation for tissue eosinophilia, should be performed in patients with chronic GI symptoms. Accurate diagnosis of EG/EoD is required for appropriate, targeted treatment and improved outcomes of patients with moderate-to-severe GI symptoms.

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Individualized Responses of Gut Microbiota to Dietary Intervention Modeled in Humanized Mice

mSystems ◽

10.1128/msystems.00098-16 ◽

2016 ◽

Vol 1 (5) ◽

Cited By ~ 24

Author(s):

Samuel A. Smits ◽

Angela Marcobal ◽

Steven Higginbottom ◽

Justin L. Sonnenburg ◽

Purna C. Kashyap

Keyword(s):

Gut Microbiota ◽

Dietary Intervention ◽

Scientific Evidence ◽

Marker Gene ◽

Gastrointestinal Symptoms ◽

Dietary Interventions ◽

Inflammatory Bowel ◽

Irritable Bowel ◽

And Function ◽

Generation Sequencing

ABSTRACT Dietary modification has long been used empirically to modify symptoms in inflammatory bowel disease, irritable bowel syndrome, and a diverse group of diseases with gastrointestinal symptoms. There is both anecdotal and scientific evidence to suggest that individuals respond quite differently to similar dietary changes, and the highly individualized nature of the gut microbiota makes it a prime candidate for these differences. To overcome the typical confounding factors of human dietary interventions, here we employ ex-germfree mice colonized by microbiotas of three different humans to test how different microbiotas respond to a defined change in carbohydrate content of diet by measuring changes in microbiota composition and function using marker gene-based next-generation sequencing and metabolomics. Our findings suggest that the same diet has very different effects on each microbiota’s membership and function, which may in turn explain interindividual differences in response to a dietary ingredient. Diet plays an important role in shaping the structure and function of the gut microbiota. The microbes and microbial products in turn can influence various aspects of host physiology. One promising route to affect host function and restore health is by altering the gut microbiome using dietary intervention. The individuality of the microbiome may pose a significant challenge, so we sought to determine how different microbiotas respond to the same dietary intervention in a controlled setting. We modeled gut microbiotas from three healthy donors in germfree mice and defined compositional and functional alteration following a change in dietary microbiota-accessible carbohydrates (MACs). The three gut communities exhibited responses that differed markedly in magnitude and in the composition of microbiota-derived metabolites. Adjustments in community membership did not correspond to the magnitude of changes in the microbial metabolites, highlighting potential challenges in predicting functional responses from compositional data and the need to assess multiple microbiota parameters following dietary interventions. IMPORTANCE Dietary modification has long been used empirically to modify symptoms in inflammatory bowel disease, irritable bowel syndrome, and a diverse group of diseases with gastrointestinal symptoms. There is both anecdotal and scientific evidence to suggest that individuals respond quite differently to similar dietary changes, and the highly individualized nature of the gut microbiota makes it a prime candidate for these differences. To overcome the typical confounding factors of human dietary interventions, here we employ ex-germfree mice colonized by microbiotas of three different humans to test how different microbiotas respond to a defined change in carbohydrate content of diet by measuring changes in microbiota composition and function using marker gene-based next-generation sequencing and metabolomics. Our findings suggest that the same diet has very different effects on each microbiota’s membership and function, which may in turn explain interindividual differences in response to a dietary ingredient. Author Video: An author video summary of this article is available.

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