Food intake and usual dietary intake are among the key determinants of health to be assessed in medical research and important confounding factors to be accounted for in clinical studies. Although various methods are available for gathering dietary data, those based on innovative technologies are particularly promising. With combined cost-effectiveness and ease of use, it is safe to assume that mobile technologies can now optimize tracking of eating occasions and dietary behaviors. Yet, choosing a dietary assessment tool that meets research objectives and data quality standards remains challenging. In this paper, we describe the purposes of collecting dietary data in medical research and outline the main considerations for using mobile dietary assessment tools based on participant and researcher expectations.

Background Gastrointestinal (GI) discomfort is prevalent and known to be associated with impaired quality of life. Real-world information on factors of GI discomfort and solutions used by people is, however, limited. Social media, including online forums, have been considered a new source of information to examine the health of populations in real-life settings. Objective The aims of this retrospective infodemiology study are to identify discussion topics, characterize users, and identify perceived determinants of GI discomfort in web-based messages posted by users of French social media. Methods Messages related to GI discomfort posted between January 2003 and August 2018 were extracted from 14 French-speaking general and specialized publicly available online forums. Extracted messages were cleaned and deidentified. Relevant medical concepts were determined on the basis of the Medical Dictionary for Regulatory Activities and vernacular terms. The identification of discussion topics was carried out by using a correlated topic model on the basis of the latent Dirichlet allocation. A nonsupervised clustering algorithm was applied to cluster forum users according to the reported symptoms of GI discomfort, discussion topics, and activity on online forums. Users’ age and gender were determined by linear regression and application of a support vector machine, respectively, to characterize the identified clusters according to demographic parameters. Perceived factors of GI discomfort were classified by a combined method on the basis of syntactic analysis to identify messages with causality terms and a second topic modeling in a relevant segment of phrases. Results A total of 198,866 messages associated with GI discomfort were included in the analysis corpus after extraction and cleaning. These messages were posted by 36,989 separate web users, most of them being women younger than 40 years. Everyday life, diet, digestion, abdominal pain, impact on the quality of life, and tips to manage stress were among the most discussed topics. Segmentation of users identified 5 clusters corresponding to chronic and acute GI concerns. Diet topic was associated with each cluster, and stress was strongly associated with abdominal pain. Psychological factors, food, and allergens were perceived as the main causes of GI discomfort by web users. Conclusions GI discomfort is actively discussed by web users. This study reveals a complex relationship between food, stress, and GI discomfort. Our approach has shown that identifying web-based discussion topics associated with GI discomfort and its perceived factors is feasible and can serve as a complementary source of real-world evidence for caregivers.

BACKGROUND Probiotics are a promising solution for managing irritable bowel syndrome (IBS). Saccharomyces cerevisiae ( S. cerevisiae ) I-3856 has already demonstrated beneficial effects in IBS subjects, particularly in IBS with predominant constipation (IBS-C). AIM To confirm the efficacy of S. cerevisiae I-3856 in the management of gastrointestinal symptoms in IBS-C. METHODS A randomized, double-blind, placebo-controlled clinical study was performed in a total of 456 subjects. After a run-in period, subjects were randomly assigned to the group receiving S. cerevisiae I-3856 (8 × 10 9 CFU daily) or the placebo for 8 wk, and they performed daily self-evaluations of gastrointestinal symptoms. The primary objective was to assess the effect of the probiotic on abdominal pain. The secondary objectives were the evaluation of other gastrointestinal symptoms, bowel movement frequency and consistency, and quality of life (QOL). RESULTS A significantly higher proportion of abdominal pain responders was reported in the Probiotic group (45.1% vs 33.9%, P = 0.017). A nonsignificant difference in the area under the curve for abdominal pain over the second month of supplementation was observed in subjects receiving probiotic vs placebo [ P = 0.073, 95%CI: -0.59 (-1.23; 0.05)]. No statistically significant differences were reported in the evolution of bowel movement frequency and stool consistency between the groups. After 8 wk of supplementation, the overall QOL score was significantly higher in the Probiotic group than in the Placebo group [ P = 0.047, 95%CI: 3.86 (0.52; 7.20)]. Furthermore, exploratory analyses showed statistically significant and clinically relevant improvements in QOL scores in abdominal pain responders vs nonresponders. CONCLUSION The results of this clinical study confirmed the abdominal pain alleviation properties of S. cerevisiae I-3856 in IBS-C. Abdominal pain relief was associated with improved QOL. ClinicalTrials.gov identifier: NCT03150212.

In a context of rising interest in food and supplement clinical trials, operational considerations for the set-up and conduct of these research projects remain difficult to address in the absence of a harmonized referential. Food trials tend to be more pragmatic than drug trials which are usually more elucidatory. However, comparing them is difficult because the objectives they serve are different. Food trials are usually conducted to evaluate the effect of food products on the prevention or mitigation of symptoms, not the treatment or cure of a condition. In this article we explain these main differences and discuss several key operational and regulatory aspects to consider when dealing with clinical research evaluating the effect of food products on health-related biomedical or behavioral outcomes.

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