The diagnosis of functional constipation (FC) relies on patient-reported outcomes evaluated as criteria based on the clustering of symptoms. Although the ROME IV criteria for FC diagnosis is relevant for a multicultural population(1), how an individual’s lifestyle, environment and culture may influence the pathophysiology of FC remains a gap in our knowledge. Building on insights into mechanisms underpinning disorders of gut-brain interactions (formerly functional gastrointestinal disorders) in the COMFORT Cohort(2), this study aimed to investigate the differences in gastrointestinal (GI) symptom scores among participants with FC in comparison to healthy controls between Chinese and non-Chinese New Zealanders. The Gastrointestinal Understanding of Functional Constipation In an Urban Chinese and Urban non-Chinese New Zealander Cohort (GUTFIT) study was a longitudinal cohort study, which aimed to determine a comprehensive profile of characteristics and biological markers of FC between Chinese and non-Chinese New Zealanders. Chinese (classified according to maternal and paternal ethnicity) or non-Chinese (mixed ethnicities) adults living in Auckland classified as with or without FC based on ROME IV were enrolled. Monthly assessment (for 3 months) of GI symptoms, anthropometry, quality of life, diet, and biological samples were assessed monthly over March to June 2023. Demographics were obtained through a self-reported questionnaires and GI symptoms were assessed using the Gastrointestinal Symptom Rating Scale (GSRS) and Structured Assessment of Gastrointestinal Symptoms Scale (SAGIS). This analysis is a cross-sectional assessment of patient-reported outcomes of GI symptoms. Of 78 enrolled participants, 66 completed the study (male, n = 10; female, n = 56) and were distributed across: Chinese with FC (Ch-FC; n = 11), Chinese control (Ch-CON; n = 19), non-Chinese with FC (NCh-FC; n = 16), non-Chinese control (NCh-CON; n = 20). Mean (SD) age, body mass index, and waist circumference were 40 ± 9 years, 22.7 ± 2.5 kg/m2, and 78.0 ± 7.6 cm, respectively. Ethnicity did not impact SAGIS domain scores for GI symptoms (Ethnicity x FC severity interaction p>0.05). Yet, the constipation symptoms domain of the GSRS was scored differently depending on ethnicity and FC status (Ethnicity x FC interaction p<0.05). In post hoc comparison, NCh-FC tended to have higher GSRS constipation severity scores than Ch-FC (3.4 ± 1.0 versus 3.8 ± 0.8 /8, p<0.1) Although constipation symptom severity tended to be higher in NCh-FC, on the whole, ethnicity did not explain variation in this cohort. FC status was a more important predictor of GI symptoms scores. Future research will assess differences in symptom burden to explore ethnicity-specific characteristics of FC.

Distinct pathophysiology has been identified with disorders of gut-brain interactions (DGBI), including functional constipation (FC)(1,2), yet the causes remain unclear. Identifying how modifiable factors (i.e., diet) differ depending on gastrointestinal health status is important to understand relationships between dietary intake, pathophysiology, and disease burden of FC. Given that dietary choices are culturally influenced, understanding ethnicity-specific diets of individuals with FC is key to informing appropriate symptom management and prevention strategies. Despite distinct genetic and cultural features of Chinese populations with increasing FC incidence(3), DGBI characteristics are primarily described in Caucasian populations(2). We therefore aimed to identify how dietary intake of Chinese individuals with FC differs to non-Chinese individuals with FC, relative to healthy controls. The Gastrointestinal Understanding of Functional Constipation In an Urban Chinese and Urban non-Chinese New Zealander Cohort (GUTFIT) study was a longitudinal case-control study using systems biology to investigate the multi-factorial aetiology of FC. Here we conducted a cross-sectional dietary intake assessment, comparing Chinese individuals with FC (Ch-FC) against three control groups: a) non-Chinese with FC (NCh-FC) b) Chinese without FC (Ch-CON) and c) non-Chinese without FC (NCh-CON). Recruitment from Auckland, New Zealand (NZ) identified Chinese individuals based on self-identification alongside both parents self-identifying as Chinese, and FC using the ROME IV criteria. Dietary intake was captured using 3-day food diaries recorded on consecutive days, including one weekend day. Nutrient analysis was performed by Foodworks 10 and statistical analysis with SPSS using a generalised linear model (ethnicity and FC status as fixed factors). Of 78 enrolled participants, 66 completed the study and 64 (39.4 ± 9.2 years) completed a 3-day food diary at the baseline assessment. More participants were female (84%) than male (16%). FC and ethnicity status allocated participants into 1 of 4 groups: Ch-FC (n = 11), Ch-CON (n = 18), NCh-FC (n = 16), NCh-CON (n = 19). Within NCh, ethnicities included NZ European (30%), non-Chinese Asian (11%), Other European (11%), and Latin American (2%). Fibre intake did not differ between Ch-FC and NCh-FC (ethnicity × FC status interaction p>0.05) but was independently lower overall for FC than CON individuals (21.8 ± 8.7 versus 27.0 ± 9.7 g, p<0.05) and overall for Ch than NCh (22.1 ± 8.0 versus 27.0 ± 10.4 g, p<0.05). Carbohydrate, protein, and fat intakes were not different across groups (p>0.05 each, respectively). In the context of fibre and macronutrient intake, there is no difference between Ch-FC and NCh-FC. Therefore, fibre and macronutrients are unlikely to contribute to potential pathophysiological differences in FC between ethnic groups. A more detailed assessment of dietary intake concerning micronutrients, types of fibre, or food choices may be indicated to ascertain whether other dietary differences exist.

The study aimed to assess the total prevalence of functional gastrointestinal disorders (FGID), and separately, irritable bowel syndrome (IBS) among adults and to determine their potential association with fructose consumption. Data from the Hellenic National Nutrition and Health Survey were included (3798 adults; 58·9 % females). Information regarding FGID symptomatology was assessed using self-reported physician diagnosis questionnaires the reliability of which were screened using the ROME III, in a sample of the population. Fructose intake was estimated from 24 h recalls, and the MedDiet score was used to assess adherence to the Mediterranean diet. The prevalence of FGID symptomatology was 20·2 %, while 8·2 % had IBS (representing 40·2 % of total FGID). The likelihood of FGID was 28 % higher (95 %CI: 1·03–1·6) and of IBS 49 % (95 %CI: 1·08–2·05) in individuals with higher fructose intake than with lower intake (3rd tertile compared with 1st). When area of residence was accounted for, individuals residing in the Greek islands had a significantly lower probability of FGID and IBS compared with those residing in Mainland and the main Metropolitan areas, with Islanders also achieving a higher MedDiet score and lower added sugar intake, comparatively to inhabitants of the main metropolitan areas. FGID and IBS symptomatology was most prominent among individuals with higher fructose consumption, and this was most conspicuous in areas with a lower Mediterranean diet adherence, suggesting that the dietary source of fructose rather than total fructose should be examined in relation to FGID.

To our knowledge, no study has assessed the relationships between patterns of dietary behaviours, identified by latent class analysis (LCA), and chronic uninvestigated dyspepsia (CUD). The present study was conducted to determine the association between the patterns of dietary behaviours, identified by LCA, and CUD in a large sample of adults. In a cross-sectional study conducted on 4763 Iranian adults, we assessed the patterns of dietary behaviours in four domains, including ‘meal patterns’, ‘eating rate’, ‘intra-meal fluid intake’ and ‘meal-to-sleep interval’, as identified by LCA, using a pre-tested comprehensive questionnaire. Patients with CUD were identified using the Rome III diagnostic criteria. CUD was prevalent in 15·2 % (95 % CI 14·4, 16·2 %; n 723) of patients. Early satiation occurred in 6·3 % (n 302) of patients, bothersome postprandial fullness in 8·0 % (n 384) of patients and epigastric pain in 7·8 % (n 371) of patients. We defined two distinct classes of meal patterns: ‘regular’ and ‘irregular’. For eating rates, three classes were defined: ‘moderate’, ‘moderate-to-slow’ and ‘moderate-to-fast’. Participants were identified as ingesting fluid with meals in two major classes: ‘moderate intra-meal drinking’ and ‘high intra-meal drinking’. In terms of the interval between meals and sleeping, two distinct classes were identified: ‘short meal-to-sleep interval’ and ‘long meal-to-sleep interval’. After controlling for potential confounders, the ‘irregular meal pattern’ was significantly associated with a greater odds of CUD (OR 1·42, 95 % CI 1·12, 1·78) compared with a ‘regular meal pattern’. Individuals with a ‘moderate-to-fast eating rate’ were more likely to have CUD compared with those who had a ‘moderate eating rate’ (OR 1·42, 95 % CI 1·15, 1·75). Patterns of the ‘meal-to-sleep interval’ and ‘intra-meal fluid intake’ were not significantly associated with CUD. In conclusion, the ‘irregular meal pattern’ and the ‘moderate-to-fast eating rate’ were significantly associated with a greater odds of CUD. Further prospective investigations are warranted to confirm this association.