Stress-induced abnormalities in gut monoamine levels (e.g., serotonin, dopamine, norepinephrine) have been linked to gastrointestinal (GI) dysfunction, as well as the worsening of symptoms in GI disorders. However, the influence of stress on changes across the entire intestinal monoamine biogeography has not been well-characterized, especially in the days following stress exposure. Therefore, the aim of this study was to comprehensively assess changes to monoamine neurochemical signatures across the entire rat intestinal tract days after exposure to an acute stressor. To the end, adult male F344 rats were subjected to an episode of unpredictable tail shocks (acute stress) or left undisturbed. Forty-eight hours later rats were euthanized either following a 12 h period of fasting or 30 min of food access to evaluate neurochemical profiles during the peri- and early postprandial periods. Monoamine-related neurochemicals were measured via UHPLC in regions of the small intestine (duodenum, jejunum, ileum), large intestine (cecum, proximal colon, distal colon), cecal contents, fecal contents, and liver. The results suggest a relatively wide-spread increase in measures of serotonin activity across intestinal regions can be observed 48 h after exposure to acute stress, however some evidence was found supporting localized differences in serotonin metabolization. Moreover, acute stress exposure reduced catecholamine-related neurochemical concentrations most notably in the ileum, and to a lesser extent in the cecal contents. Next, stress-related fecal serotonin concentrations were consistent with intestinal profiles. However, fecal dopamine was elevated in association with stress, which did not parallel findings in any other intestinal area. Finally, stress exposure and the food access period together only had minor effects on intestinal monoamine profiles. Taken together, these data suggest nuanced differences in monoaminergic profiles exist across intestinal regions the days following exposure to an acute stressor, highlighting the importance of assessments that consider the entire intestinal tract biogeography when investigating stress-related biological outcomes that may be relevant to GI pathophysiology.

UNASSIGNED: Heightened pain sensitivity is common in functional gut disorders, but no research has examined whether it corresponds to exercise-associated gastrointestinal (GI) symptoms. We sought to explore whether scores on a questionnaire of pain sensitivity would correlate with GI symptoms during running.
UNASSIGNED: This is a cross-sectional study.
UNASSIGNED: The study involves 290 (137 male, 153 female) distance runners.
UNASSIGNED: Runners completed a survey inquiring about demographic, anthropometric and training information and rated GI symptoms at rest and during runs. In addition, the Pain Sensitivity Questionnaire (PSQ) was used to quantify pain sensitivity across all items (PSQ-Total) and on items typically rated as minor (PSQ-Minor). Spearman rho correlations were utilized to assess the associations between pain sensitivity and GI symptoms. Partial correlations were used to evaluate the associations after controlling for age, gender, running experience, body mass index and sleep problems.
UNASSIGNED: PSQ scores weakly correlated with several GI symptoms at rest (rho = 0.13-0.20; p < 0.05), which remained largely intact in partial correlation analyses (partial rho = 0.12-0.18). PSQ scores weakly correlated with fullness, bloating and gas during runs (rho = 0.12-0.18; p < 0.05); fullness and bloating remained significant in the partial correlation analyses (partial rho = 0.12-0.15). These results were relatively consistent for both the PSQ-Total and PSQ-Minor.
UNASSIGNED: Although PSQ scores only weakly correlate with certain GI symptoms among runners, the effect sizes are similar to that of other predictors of GI distress. These results suggest a minor possible role of pain sensitivity in the development of certain GI symptoms in runners.

OBJECTIVE: The purpose of this study is to quantify the effect of adding sodium alginate and pectin to a carbohydrate (CHO) beverage on exogenous glucose (ExGluc) oxidation rate compared with an isocaloric CHO beverage.
METHODS: Following familiarization, eight well-trained endurance athletes performed four bouts of prolonged running (105 min; 71 ± 4% of VO2max) while ingesting 175 mL of one of the experimental beverages every 15 min. In randomized order, participants consumed either 70 g.h-1 of maltodextrin and fructose (10% CHO; NORM), 70 g.h-1 of maltodextrin, fructose, sodium alginate, and pectin (10% CHO; ENCAP), 180 g.h-1 of maltodextrin, fructose, sodium alginate, and pectin (26% CHO; HiENCAP), or water (WAT). All CHO beverages had a maltodextrin:fructose ratio of 1:0.7 and contained 1.5 g.L-1 of sodium chloride. Total substrate oxidation, ExGluc oxidation rate, blood glucose, blood lactate, serum non-esterified fatty acid (NEFA) concentration, and RPE were measured for every 15 min. Every 30 min participants provided information regarding their gastrointestinal discomfort (GID).
RESULTS: There was no significant difference in peak ExGluc oxidation between NORM and ENCAP (0.63 ± 0.07 and 0.64 ± 0.11 g.min-1, respectively; p > 0.5), both of which were significantly lower than HiENCAP (1.13 ± 0.13 g.min-1, p < 0.01). Both NORM and HiENCAP demonstrated higher total CHO oxidation than WAT from 60 and 75 min, respectively, until the end of exercise, with no differences between CHO trials. During the first 60 min, blood glucose was significantly lower in WAT compared with NORM and HiENCAP, but no differences were found between CHO beverages. Both ENCAP and HiENCAP demonstrated a higher blood glucose concentration from 60-105 min than WAT, and ENCAP was significantly higher than HiENCAP. There were no significant differences in reported GID symptoms between the trials.
CONCLUSIONS: At moderate ingestion rates (i.e., 70 g.h-1), the addition of sodium alginate and pectin did not influence the ExGluc oxidation rate compared with an isocaloric CHO beverage. At very high ingestion rates (i.e., 180 g.h-1), high rates of ExGluc oxidation were achieved in line with the literature.

To develop and validate a questionnaire investigating endurance athletes\' carbohydrate beliefs, knowledge, information sources, and other dietary and non-dietary practices related to exercise-associated gastrointestinal symptoms.
A questionnaire was developed by a review of relevant literature and sports-related questionnaires, and input from five experienced sports dietitians. Item construct and format was adapted and modified from a previous questionnaire. The modified questionnaire sought information on demographics, nutrition knowledge, beliefs, intended practices, information sources and exercise-associated gastrointestinal symptoms. A five-phase validity process was conducted to determine content, face and construct validity, item difficulty and internal reliability of the questionnaire. The Delphi technique was applied with experts over three anonymous rounds. Items were reviewed to determine whether to keep, modify, or delete, rate the relevance of each item using a content validity index (CVI), and provide comments. A content analysis was conducted on all comments after each round. Online interviews were conducted with a pilot group of endurance athletes (n = 15) to assess item difficulty and feasibility. Nutrition knowledge was compared between pilot group of athletes and experts to determine construct validity and internal consistency. A test-retest process was applied to a second pilot group (n = 8) to verify questionnaire reliability.
High CVI (≥.83) and agreement scores were obtained through the Delphi technique. High reliability (r = .942) and acceptable internal consistency (α = .53-.78) of the questionnaire were obtained.
The questionnaire was shown to be a valid and reliable tool that will be of use for clinicians and research purposes.

Generalized anxiety disorder (GAD) is characterized, in part, by physical symptoms such as muscle tension and gastrointestinal (GI) distress. To date, little research has examined how changes in psychological symptoms associated with GAD may impact physical symptoms. This study investigated if reductions in worry, anxiety, and depression precede changes in muscle tension and GI distress throughout psychotherapy.
Participants with GAD (N = 85) completed 20 weeks of emotion regulation therapy (ERT) in addition to assessments pre, mid, and post treatment. They completed a physical symptom questionnaire, evaluating muscle tension and GI distress. Participants also completed psychological symptoms questionnaires, including the State Trait Anxiety Inventory (STAI-7), Penn State Worry Questionnaire (PSWQ), and Beck Depression Inventory (BDI-II). Control participants (N = 44) completed these measures at baseline.
Participants with GAD had significantly greater muscle tension (p <  .001) and GI distress (p <  .001) compared to control participants without GAD. Reductions in worry, depression, and trait anxiety did not precede changes in muscle tension (range of effect size (r): .05-.12). Reductions in both depression (p = 0.04) and trait anxiety (p < 0.01) preceded reductions in GI distress. Reductions in worry did not precede reductions in GI distress (p = 0.25).
These data provide preliminary evidence for the temporal effect of reductions in psychological symptoms on reductions in GI distress in GAD, highlighting the potential of psychotherapy to improve physical outcomes.

Background: Cholelithiasis is currently one of the most common diagnosis in Brazil. The aim of this study was to validate the Gastrointestinal Quality of Life Index (GIQLI) as a quality-of-life (QoL) assessment among the Brazilian population with syntomatic gallstone. Materials and Methods: The questionnaire was translated and culturally adapted after the linguistic validation process determined by the international methodology. Sixty-three patients who underwent laparoscopic cholecystectomy responded to the GIQLI-Brazil and Short-Form Health Survey (SF-36) instruments. For the evaluation of reproducibility, 30 patients responded to GIQLI-Brazil two more times after 2 and 4 weeks. After the University of São Paulo Ethics Commitee Board approval (UNIFESP/CEP: 1270/2019), the study was carryed out between May 2019 and February 2020 at the Gastroenterology outpatient clinic of Hospital São Paulo-Federal University of São Paulo (UNIFESP). Cronbach\'s alpha, the calculation of the intraclass correlation coefficient (ICC), and Spearman\'s correlation were used to assess the validity and reproducibility of the instrument translated into Portuguese, and to measure correlation between the domains of the GIQLI-Brazil and SF-36 (P < .05). Results: Seven questions were modified during the process of translation and cultural adaptation. The Brazilian version of the instrument presented a Cronbach\'s alpha of 0.89, and excellent reproducibility through the ICC, with the following variation between domains: meteorism (ICC = 0.918; P < .001) and gastrointestinal function (lower tract) (ICC = 0.956; P < .001). The dimensions of the GIQLI-Brazil and SF-36 demonstrated a significant correlation (P < .001), except between the domains: functional aspects of the SF-36 and gastrointestinal function (lower tract) of the GIQLI-Brazil (r = 0.211). Conclusion: The GIQLI was translated and validated for Portuguese-Brazil and can be used to assess the QoL of adult patients with gastrointestinal diseases and/or disorders.

In this article, we focus on adults with primary immunodeficiency disease (PID) and their experiences with gastrointestinal (GI) distress with the aim of exploring how they experience living with their condition and the actions they take to relieve GI distress. Twelve adults with PID and GI distress participated in semi-structured, in-depth interviews. The interviews were analyzed following the steps of thematic analysis (TA). The study revealed the complexity of the psychosocial aspects of living with PID and GI distress. Participants experienced GI distress to be highly challenging in daily life and felt they had to cope with the condition alone, without adequate help from the health care service. Participants used a wide and diverse range of coping strategies, and the search for normalcy was evident. Health care professionals should be more proactive in supporting individuals with PID in their struggle to find solutions to problems arising from GI distress.

To determine the effects of pre-sleep supplementation with a novel low glycemic index (LGI) carbohydrate (CHO) on next-morning substrate utilization, gastrointestinal distress (GID), and endurance running performance (5-km time-trial, TT). Using a double-blind, randomized, placebo (PLA) controlled, crossover design, trained participants (n = 14; 28 ± 9 years, 8/6 male/female, 55 ± 7 mL/kg/min) consumed a LGI, high glycemic index (HGI), or 0 kcal PLA supplement ≥ 2 h after their last meal and <30 min prior to sleep. Upon arrival, resting energy expenditure (REE), substrate utilization, blood glucose, satiety, and GID were assessed. An incremental exercise test (IET) was performed at 55, 65, and 75% peak volume of oxygen consumption (VO2peak) with GID, rating of perceived exertion (RPE) and substrate utilization recorded each stage. Finally, participants completed the 5-km TT. There were no differences in any baseline measure. During IET, CHO utilization tended to be greater with LGI (PLA, 56 ± 11; HGI, 60 ± 14; LGI, 63 ± 14%, p = 0.16, η2 = 0.14). GID was unaffected by supplementation at any point (p > 0.05). Performance was also unaffected by supplement (PLA, 21.6 ± 9.5; HGI, 23.0 ± 7.8; LGI, 24.1 ± 4.5 min, p = 0.94, η2 = 0.01). Pre-sleep CHO supplementation did not affect next-morning resting metabolism, BG, GID, or 5-km TT performance. The trend towards higher CHO utilization during IET after pre-sleep LGI, suggests that such supplementation increases morning CHO availability.

The present guidelines for sports nutrition recommend relatively higher doses of carbohydrates (CHO) for endurance exercise. There is a need for novel food products that are solid but easy to swallow and supply a large dose of CHO without gastrointestinal distress (ingesting a large amount of sugar solution may cause gastrointestinal distress because of its high osmolality). We prepared a modified rice cake (SPRC, sweet potato rice cake) and assessed its properties in swallowing and mastication; we also assessed the availability of this modified rice cake as a CHO source during endurance exercise. The number of chewing strokes with the SPRC tended to be lower compared to glutinous rice cakes. The exercise protocol consisted of 1 h at 80% VO2max plus a continuous time trial. The subjects were administered a commercially available jelly drink (CHO gel) or SPRC at 0 and 30 min during exercise and immediately after completing the time trial. Heart rate, oxygen consumption, blood glucose elevation, and the rate of perceived exertion did not differ among the trials during exercise. However, the visual analog scale rating revealed that SPRC significantly suppressed hunger and sweetness ratings (p<0.05) and tended to suppress thirst ratings (p<0.10) during exercise. The palatability rating did not differ between the SPRC and CHO gel during exercise at 80% VO2max and immediately after the time trial. In conclusion, pre- and during exercise ingestion of the SPRC suppressed sweetness, thirst, and hungry ratings without interfering with exercise performance.

OBJECTIVE: This study examined the effects of a novel maltodextrin-fructose hydrogel supplement (MF-H) on cycling performance and gastrointestinal distress symptoms.
METHODS: Nine endurance-trained male cyclists (age = 26.1 ± 6.6, mass = 80.9 ± 10.4 kg, VO2max = 55.5 ± 3.6 mL·kg·min-1) completed three experimental trials consisting of a 98-min varied-intensity cycling protocol followed by a performance test of ten consecutive sprint intervals. In a cross-over design, subjects consumed 250 mL of a treatment beverage every 15 min of cycling. Treatments consisted of 78 g·hr-1 of either (a) MF-H, (b) isocaloric maltodextrin-fructose (ratio-matched 2:1; MF), and (c) isocaloric maltodextrin only (MD).
RESULTS: There were no differences in average sprint power between treatments (MF-H, 284 ± 51 W; MF, 281 ± 46 W; and MD, 277 ± 48 W), or power output for any individual sprint. Subjective ratings of gastrointestinal distress symptoms (nausea, fullness, and abdominal cramping) increased significantly over time during the cycling trials, but few individuals exceeded moderate levels in any trial with no systematic differences in gastrointestinal discomfort symptoms observed between treatments.
CONCLUSIONS: In conclusion, ingestion of a maltodextrin/fructose hydrogel beverage during high-intensity cycling does not improve gastrointestinal comfort or performance compared to MF or MD beverages.