Adherence to the pro-inflammatory diet in relation to prevalence of irritable bowel syndrome

Proinflammatory Diet Increases the Risk of Irritable Bowel Syndrome: A Prospective Study of 129,408 UK Biobank Participants and Mendelian Randomization Analysis

BACKGROUND

Patients with irritable bowel syndrome (IBS) often have chronic low-grade inflammation in the intestinal mucosa. Some dietary components are known to be associated with inflammation. However, there is currently limited research on the relationship between dietary inflammatory potential and the risk of IBS.

METHODS

A total of 129,408 participants in the UK Biobank were included in this study. Energy-Adjusted Dietary Inflammatory Index (E-DII) based on 26 nutrients and the Empirical Dietary Inflammatory Pattern (EDIP) based on 17 food groups were constructed, and on the basis of the tertiles, the continuous score was categorized into proinflammatory, neutral, and antiinflammatory categories. Associations between IBS and E-DII and EDIP were investigated by multivariable Cox proportional hazard models. Potential confounders including sociodemographic, lifestyle, body mass index (BMI), psychological state, type 2 diabetes, and thyroiditis were adjusted. In addition, subgroup analysis and sensitivity analysis were also performed. Finally, a two-sample Mendelian randomization (MR) analysis was employed to explore the independent causality of nutrients and dietary-derived serum antioxidants with IBS.

RESULTS

In the cohort study, over a median follow-up period of 13.26 years, 2421(1.87%) participants developed IBS. In the E-DII categories, after adjusting for the confounders, individuals in the proinflammatory diet category had a higher risk of IBS compared with the antiinflammatory category (HR 1.15, 95% CI 1.03-1.28, p = 0.015, p trend = 0.017) and neutral category (HR 1.13, 95% CI 1.01-1.26, p = 0.030, p trend = 0.017). In the EDIP categories, after adjusting for the confounders, individuals in the proinflammatory diet category had a higher risk of IBS compared with antiinflammatory category (HR 1.19, 95% CI 1.06-1.33, p = 0.002, p trend = 0.002) but no significant association compared with neutral category (HR 1.10, 95% CI 0.99-1.23, p = 0.067, p trend = 0.002). In the MR analysis, genetically determined intake levels of 16 nutrients and 6 dietary sources of circulating antioxidants did not have a causal effect on IBS.

CONCLUSIONS

Our findings indicate that proinflammatory dietary components are independent risk factors for IBS. However, there is no causal relationship between individual nutrient intake or serum antioxidants from dietary sources and IBS.

Associations of dietary patterns with risk of gastrointestinal disorders: a prospective cohort study

Gastrointestinal (GI) disorders are highly prevalent and severely diminish life quality. It is yet unknown which dietary pattern is optimal for the prevention of GI disorders. Among 141 450 participants from UK Biobank with a median follow-up of 15 years, we comprehensively assessed 13 dietary patterns in relation to 6 GI disorders. Multivariable Cox proportional hazards models demonstrated that adherence to healthy diets was associated with lower risk of GI disorders, with the strongest associations observed for the Dietary Approaches to Stop Hypertension (DASH) diet (HRQ4 vs. Q1 = 0.85, 95% CI: 0.81, 0.88), the Alternate Mediterranean Diet (AMED) (HRQ4 vs. Q1 = 0.85, 95% CI: 0.81, 0.88), and the Alternate Healthy Eating Index-2010 (AHEI-2010) (HRQ4 vs. Q1 = 0.86, 95% CI: 0.82, 0.89). AHEI-2010 (HRs ranging from 0.76 to 0.90) and DASH (HRs ranging from 0.75 to 0.88) showed inverse associations with every individual GI disorder. Furthermore, comorbidities decreased significantly in number with higher AMED and DASH diet scores (P for trend <0.001). Finally, the associations of AHEI-2010, AMED and DASH with GI disorders diminished most intensely after removing the component of fruits or whole grains. The combined intake of fruits and whole grains was inversely associated with the risk of overall GI disorders (HRT3 vs. T1 = 0.89, 95% CI: 0.86, 0.93). In conclusion, AHEI-2010 and DASH were the most recommended dietary patterns for the prevention of GI disorders. Fruits and whole grains are the most significant contributors to the protective effect.

Association between pro-inflammatory diet and abdominal pain: cross-sectional and case-control study from UK biobank and NHANES 2017-2020

BACKGROUND

There is a close association between diet and abdominal pain; however, relationship between inflammatory diet and characteristics of abdominal pain has not been characterized yet.

METHODS

This study analyzed baseline data from the UK Biobank, 3-item DHQ-Abdominal Pain Questionnaire (DHQ-3Q), which including abdominal pain in the past 3 months, severity of abdominal pain, and frequency of abdominal pain, and data from the National Health and Nutrition Examination Survey (NHANES) from 2017 to 2020. Energy-adjusted Dietary Inflammatory Index (E-DII), constructed based on 26 or 27 nutrients, was analyzed using continuous or categorical methods. Logistic regression and restricted cubic spline analyses examined the association between E-DII and abdominal pain.

RESULTS

In UK Biobank, compared to participants in the lowest quintile of E-DII, the adjusted ORs for the highest quintile were 1.12 (95% CI 1.02-1.24; P = .022), 1.05 (95% CI 1.00-1.09; P = .030), 1.26 (95% CI 1.17-1.36; P < .001), and 1.10 (95% CI 1.00-1.20; P = .044) for chronic abdominal pain, abdominal pain in the past three months, severity of abdominal pain, and frequency of abdominal pain, respectively. In NHANES, compared to participants in the lowest quintile of E-DII, the adjusted ORs for the highest quintile were 1.46 (95% CI 1.20-1.77;P < .001), 1.75 (95% CI 1.20-2.60; P = .005), 1.45 (95% CI 1.14-1.87; P = .003), and 1.18 (95% CI 0.82-1.72; P = .380) for abdominal pain in the past year, upper left abdominal pain, upper middle abdominal pain, and upper right abdominal pain. Additionally, there was a nonlinear correlation between E-DII score and DHQ-3Q (P nonlinear <.001).

CONCLUSION

Following a pro-inflammatory diet is linked to a higher likelihood of experiencing abdominal pain, as well as increased severity and frequency of such pain. Therefore, further longitudinal studies are necessary to investigate this relationship.

The association between dietary total antioxidant capacity and odds and severity of irritable bowel syndrome among Iranian adults: a cross-sectional study

BACKGROUND

Little evidence is available in terms of the role of dietary antioxidants in the management of irritable bowel syndrome (IBS) disease. This study aimed to examine the association between dietary total antioxidant capacity (dTAC) and odds of IBS and its severity.

METHODS

This cross-sectional study was conducted on 3,362 Iranian adults who were referred to health centers in Isfahan province, Iran. Participants' dietary intakes were collected using a semi-quantitative validated food frequency questionnaire (DS-FFQ). The dTAC was measured by the ferric-reducing antioxidant power (FRAP) method. Multivariable binary or ordinal logistic regression analyses were performed to estimate any associations between dTAC and odds of IBS, IBS severity, and IBS subtypes.

RESULTS

The average age and BMI of the participants and dTAC score were 36.3 ± 7.87 year, 24.9 ± 3.82 kg/m2. The prevalence of IBS, IBS with constipation (IBS-C), IBS with diarrhoea (IBS-D), mixed IBS (IBS-M), and un-subtyped IBS (IBS-U) were 22.2, 7.5, 4.6, 3.8, and 6.2%, respectively. In crude and adjusted models, the results did not show any significant association between dTAC and odds of IBS among whole and gender-age stratified populations. Being in the third compared with the first tertile of dTAC was not also significantly associated with odds of IBS severity. Besides, there were no significant associations between dTAC and odds of IBS-C, IBS-D, IBS-M, and IBS-U.

CONCLUSION

This study indicates that dTAC may not be associated with the odds of IBS and its severity even after stratification for gender and body mass index.

The association between dietary total antioxidant capacity and odds and severity of irritable bowel syndrome among Iranian adults: a cross-sectional study

Background

Little evidence is available in terms of the role of dietary antioxidants in the management of irritable bowel syndrome (IBS) disease. This study aimed to examine the association between dietary total antioxidant capacity (dTAC) and odds of IBS and its severity.

Methods

This cross-sectional study was conducted on 3,362 Iranian adults who were referred to health centers in Isfahan province, Iran. Participants' dietary intakes were collected using a semi-quantitative validated food frequency questionnaire (DS-FFQ). The dTAC was measured by the ferric-reducing antioxidant power (FRAP) method. Multivariable binary or ordinal logistic regression analyses were performed to estimate any associations between dTAC and odds of IBS, IBS severity, and IBS subtypes.

Results

The average age and BMI of the participants and dTAC score were 36.3 ± 7.87 year, 24.9 ± 3.82 kg/m2. The prevalence of IBS, IBS with constipation (IBS-C), IBS with diarrhoea (IBS-D), mixed IBS (IBS-M), and un-subtyped IBS (IBS-U) were 22.2, 7.5, 4.6, 3.8, and 6.2%, respectively. In crude and adjusted models, the results did not show any significant association between dTAC and odds of IBS among whole and gender-age stratified populations. Being in the third compared with the first tertile of dTAC was not also significantly associated with odds of IBS severity. Besides, there were no significant associations between dTAC and odds of IBS-C, IBS-D, IBS-M, and IBS-U.

Conclusion

This study indicates that dTAC may not be associated with the odds of IBS and its severity even after stratification for gender and body mass index.

Association between body mass index and irritable bowel syndrome in the young Japanese population: a cross-sectional study

PURPOSE

The association between body mass index (BMI) and irritable bowel syndrome (IBS) has been inconsistent in the Asian population. Also, no evidence regarding this issue in the young population exists. The aim of the present study is to investigate the association between BMI and IBS based on the Rome III criteria in young Japanese people.

METHODS

This study was a cross-sectional study consisted of 8923 Japanese university students. The definition of IBS was based on the Rome III criteria. BMI was divided into four categories (quartiles) on the basis of the study subjects' distribution (lowest, low, moderate, and high [reference]). The definition of lean, normal, and overweight was BMI < 18.5 kg/m², 18.5 ≤ BMI < 25 kg/m² (reference), and 25 ≤ BMI kg/m², respectively. Age, sex, drinking, smoking, exercise habit, anemia, and sports injury were selected a priori as potential confounding factors.

RESULTS

The prevalence of IBS was 6.5%, with females having a significantly higher prevalence than males (6.0% vs. 7.2%, p = 0.029). In females, being overweight was independently positively associated with IBS after adjustment (adjusted odds ratio [OR]: 1.81 [95% confidence interval (CI): 1.13-2.79]). In contrast, in males, no association between being lean or overweight and IBS was found.

CONCLUSIONS

Among the young Japanese population, being overweight might be independently positively associated with prevalence of IBS in females but not in males.

Role of the duodenal microbiota in functional dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a common and debilitating gastrointestinal disorder attributed to altered gut-brain interactions. While the etiology of FD remains unknown, emerging research suggests the mechanisms are likely multifactorial and heterogenous among patient subgroups. Small bowel motor disturbances, visceral hypersensitivity, chronic microinflammation, and increased intestinal tract permeability have all been linked to the pathogenesis of FD. Recently, alterations to the gut microbiome have also been implicated to play an important role in the disease. Changes to the duodenal microbiota may either trigger or be a consequence of immune and neuronal disturbances observed in the disease, but the mechanisms of influence of small intestinal flora on gastrointestinal function and symptomatology are unknown.

PURPOSE

This review summarizes and synthesizes the literature on the link between the microbiota, low-grade inflammatory changes in the duodenum and FD. This review is not intended to provide a complete overview of FD or the small intestinal microbiota, but instead outline some of the key conceptual advances in understanding the interactions between altered gastrointestinal bacterial communities; dietary factors; host immune activation; and stimulation of the gut-brain axes in patients with FD versus controls. Current and emerging treatment approaches such as dietary interventions and antibiotic or probiotic use that have demonstrated symptom benefits for patients are reviewed, and their role in modulating the host-microbiota is discussed. Finally, suggested opportunities for diagnostic and therapeutic improvements for patients with this condition are presented.

Adult patients with allied disorders of Hirschsprung’s disease in emergency department: An 11-year retrospective study

BACKGROUND

In the past years, only a few studies with a limited number of adult patients analyzed clinical features of allied disorders of Hirschsprung’s disease (ADHD), most of which were individual case reports or lacked detailed clinical information. Although many studies have reported patients presenting to the emergency department (ED) with recurrent abdominal symptoms for a number of disorders, there are few data involving ADHD. However, owing to a lack of awareness of the disease, misdiagnoses and mistreatments are common. Severe complications such as perforation, bleeding, malabsorption, and even death in ADHD had been reported by many studies.

AIM

To assist ED clinicians in having a more comprehensive understanding of this disease and making an early suspected diagnosis of ADHD more effectively.

METHODS

We enrolled 53 patients who visited the ED and were eventually diagnosed with ADHD over the past 11 years in our hospital. Their basic information, clinical manifestations, and imaging findings were analyzed. Blood indices were compared between the ADHD and irritable bowel syndrome (IBS) groups.

RESULTS

Adult patients with ADHD had a mean age of 48.8 ± 14.3 years, and 77.4% had been treated before admission. The transverse colon was the most common dilated part (73.6%), and constipation (67.9%) was the most common symptom. ADHD patients can present with uncommon symptoms and false-negative imaging findings. Logistic regression analysis indicated that body mass index (BMI) [odds ratio (OR) = 0.786, P = 0.013], cholinesterase (per 1000 units; OR = 0.693, P = 0.008), and blood chlorine (OR = 0.816, P = 0.022) were determined to be independent related factors between the ADHD and IBS groups. The area under the receiver operating characteristics curve of these three indices combined was 0.812 (P < 0.001).

CONCLUSION

Emergency physicians should be vigilant regarding patients with chronic constipation, abdominal pain, or abdominal distension, and consider the possibility of ADHD despite its rarity. Abdominal computed tomography examination is recommended as a useful tool in the suspected diagnosis of ADHD. BMI, cholinesterase, and blood chlorine have good discriminative abilities between ADHD and IBS. The nutritional status of adult patients with ADHD is worthy of further attention. Surgical treatment for adult patients with ADHD is important and inevitable.

Dietary and Lifestyle Inflammation Scores Are Inversely Associated with Metabolic-Associated Fatty Liver Disease among Iranian Adults: A Nested Case-Control Study

BACKGROUND

Diet and lifestyle may affect risk for metabolic-associated fatty liver disease (MAFLD) by chronically elevating systemic inflammation.

OBJECTIVES

In this study we investigated the separate and joint associations of dietary and lifestyle inflammation scores (DIS and LIS, respectively) with MAFLD risk.

METHODS

For this nested case-control study we identified and recruited 968 patients with MAFLD (defined as having a fatty liver index ≥60 plus ≥1 of the following conditions: overweight or obese, type II diabetes mellitus, evidence of metabolic dysregulation) and 964 controls from among 35-70-y-old men and women in the baseline phase of the Sabzevar Persian Cohort Study. We collected demographic, lifestyle, anthropometric, biochemical, and dietary intake information (via a validated FFQ) from which we calculated a circulating inflammation biomarker-weighted, predominantly whole foods and beverages-based, 19-component DIS and a 3-component LIS. We estimated DIS- and LIS-MAFLD associations using multivariable unconditional logistic regression. We also calculated equal-weight DIS and LIS to capture all potential mechanisms (inflammation plus other mechanisms) for associations of diet and lifestyle with MAFLD risk.

RESULTS

Among those in the highest relative to the lowest DIS and LIS tertiles, the multivariable-adjusted ORs and their 95% CIs were OR: 1.84; 95% CI: 1.61, 2.07; Ptrend < 0.001, and OR: 1.96; 95% CI: 1.69, 2.21; Ptrend < 0.001, respectively. For those in the highest relative to the lowest joint DIS and LIS tertile, the values were OR: 2.56; 95% CI: 2.19, 2.93; Pinteraction < 0.001. The findings were similar by sex. The third tertile values for the equal-weight DIS- and LIS-MAFLD associations were OR: 1.87; 95% CI: 1.41, 2.34; and OR: 2.16; 95% CI: 1.85, 2.46, respectively.

CONCLUSIONS

Our results suggest that higher balances of pro- relative to anti-inflammatory dietary and lifestyle exposures, separately and especially jointly, may be associated with higher MAFLD risk among adults. Also, inflammation may be the primary mechanism through which diet affects MAFLD risk.

Dietary Inflammatory Potential in relation to General and Abdominal Obesity

Background/Aims: Limited data are available on the association of Dietary Inflammatory Potential (DIP) with general and abdominal obesity in developing countries. The aim of this study was to examine the association between DIP score with general and abdominal obesity among Iranian adults. Methods. This cross-sectional study was conducted among adults in Isfahan, Iran. Dietary intakes were assessed by using a validated, self-administrated, dish-based, semiquantitative food frequency questionnaire. DIP was calculated based on standard method. Data regarding height, weight, and waist circumference (WC) were collected using a self-reported questionnaire. Overweight or obesity was defined as body mass index (BMI) ≥25 kg/m2, and abdominal obesity was defined as WC ≥ 80 cm for women and ≥94 cm for men. Results. Mean age of study participants was 36.8 ± 8.08 years. The prevalence of general and abdominal obesity was 46.5% and 52.9%, respectively. We observed that higher DIP scores were significantly associated with a lower odds of general obesity (OR: 0.66; 95% CI: 0.58-0.74). Stratified by sex, this significant association was seen only for women (OR: 0.58; 95% CI: 0.46-0.72). In addition, no significant association was found between DIP scores and abdominal obesity. Conclusions. We found a significant inverse association between consumption of a proinflammatory diet and general obesity. In the gender-stratified analysis, this was seen in women, but not in men. There was no significant association between the DIP scores and abdominal obesity.

Greater Dietary Inflammatory Potential Is Associated With Higher Likelihood of Abdominal Aortic Calcification

Aims: We aimed to assess the association between dietary inflammation index (DII) and abdominal aortic calcification (AAC) in US adults aged ≥40 years. Methods: Data were obtained from the 2013-2014 National Health and Nutrition Examination Survey (NHANES). Participants who were <40 years old and missing the data of DII and AAC were excluded. DII was calculated based on a 24-h dietary recall interview for each participant. AAC score was quantified by assessing lateral spine images and severe AAC was defined as AAC score >6. Weighted multivariable regression analysis and subgroup analysis were preformed to estimate the independent relationship between DII with AAC score and severe AAC. Results: A total of 2,897 participants were included with the mean DII of -0.17 ± 2.80 and the mean AAC score of 1.462 ± 3.290. The prevalence of severe AAC was 7.68% overall, and participants in higher DII quartile tended to have higher rates of severe AAC (Quartile 1: 5.03%, Quartile 2: 7.44%, Quartile 3: 8.38%, Quartile 4: 10.46%, p = 0.0016). A positive association between DII and AAC score was observed (β = 0.055, 95% CI: 0.010, 0.101, p = 0.01649), and higher DII was associated with an increased risk of severe AAC (OR = 1.067, 95% CI: 1.004, 1.134, p = 0.03746). Subgroup analysis indicated that this positive association between DII and AAC was similar in population with differences in gender, age, BMI, hypertension status, and diabetes status and could be appropriate for different population settings. Conclusion: Higher pro-inflammatory diet was associated with higher AAC score and increased risk of severe AAC. Anti-inflammatory dietary management maybe beneficial to reduce the risk of AAC.

Typical dietary habits and elevated intestinal permeability in people with excess body weight and IBS

To optimize non-drug methods of treatment of patients with irritable bowel syndrome (IBS) against the background of obesity to identify the peculiarities of food preferences and permeability of the intestinal wall.

Materials and methods: An anonymous questionnaire survey of 52 IBS patients was carried out using the author’s set of dietary assessment questions “Nutrition Information and Food Behavior” developed at the Department of Hygiene, Human Nutrition of Omsk State Medical University. The study of the level of zonulin in the feces was carried out at the Central Research Laboratory of the Federal State Budgetary Educational Institution of Higher Professional Education Omsk State Medical University of the Ministry of Health of Russia by enzyme immunoassay using the IDK Zonulin ELISA test system (Immundiagnostik, Germany).

Results: The eating habits of IBS patients with BMI ≥25 kg/m2 diff er from those of normal weight patients and can be considered a component of the phenotype of this patient cohort. IBS patients with BMI ≥25 kg/m2 have a higher level of intestinal permeability as assessed by zonulin content in feces.

"Association between dietary inflammatory index (DII) and risk of irritable bowel syndrome: a case-control study"

Background

Pathophysiology of IBS is not well recognized; however, several studies have shown the possible relationship between diet and risk of IBS. We assessed the ability of the dietary inflammatory index (DII) to predict the risk of IBS.

Methods

The subjects were 155 IBS cases and 310 age- and sex-matched healthy controls (aged ≥18 years). The participants were recruited from June, 2019 to March, 2020. IBS was recognized using the Rome IV criteria. DII score was computed based on dietary intake using a 168-item FFQ. The DII score was calculated based on energy-adjusted amounts of nutrients using residual method. Logistic regression models were used to estimate multivariable odds ratios (ORs).

Results

The mean DII score was significantly higher among IBS patients in comparison to healthy controls (0.78 ± 2.22 vs. − 0.39 ± 2.27). In crude model, increase in DII as continuous variable was associated with a significant increase in the risk of IBS (OR (95% CI): 1.26 (1.1–15.38)). Furthermore, the association remained significant even after adjusting for age and sex (OR (95% CI): 1.28 (1.1–17.41)) and after multivariate adjustment (OR (95% CI): 1.38 (1.2–1.56)). In crude, age and sex adjusted and multivariate-adjusted models subjects in fourth quartile of DII had higher OR in comparison to subjects in first quartile.

Conclusions

This study showed a possible positive association between a pro-inflammatory diet and the risk of IBS. Thus, encouraging intake of more anti-inflammatory dietary factors and reducing intake of pro-inflammatory factors may be a strategy for reducing risk of IBS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00721-5.

Dietary inflammatory index and dietary energy density are associated with menopausal symptoms in postmenopausal women: a cross-sectional study

OBJECTIVES

No previous study has evaluated the association of the dietary inflammatory index (DII) and dietary energy density (DED) with menopausal symptoms and its subclasses in postmenopausal women. The aim of this study was to evaluate the association of DII score and DED with menopausal symptoms and its subtypes in Iranian postmenopausal women.

METHODS

This cross-sectional study was conducted on 393 postmenopausal women who attended health centers in the south of Tehran, Iran. The DII score was calculated using dietary factors obtained by a validated food frequency questionnaire. DED was defined as average daily energy intake (kcal) per gram of food. The Menopause Rating Scale questionnaire was used to evaluate the menopausal symptoms. The total Menopause Rating Scale score (TMRSS) was the sum of the somatic score (SS), psychological score (PS), and urogenital score. Linear regression analysis was used to assess the association of the DII score and DED with menopausal symptoms.

RESULTS

After adjusting for covariates, participants in the highest tertile of DII score had greater SS compared to those in the lowest tertile (βDIIt3vs1= 0.032, 95% confidence interval (CI): 0.004-0.068, P = 0.04). No significant relationship was found between DII score and PS, urogenital score or TMRSS. Furthermore, higher DED was associated with greater SS (βDIIt3vs1 = 0.071, 95% CI: 0.028-0.115, P = 0.001), PS (βDIIt3vs1 = 0.065, 95% CI: 0.012-0.121, P = 0.01) and TMRSS (βDIIt3vs1 = 0.053, 95% CI: 0.017-0.088, P = 0.004).

CONCLUSION

A proinflammatory diet was associated with higher menopause-specific somatic symptoms and higher DED was positively associated with menopausal symptoms.

Differences in dietary habits of people with vs without irritable bowel syndrome and their association with symptom and psychological status: A pilot study

BACKGROUND

Previous studies have demonstrated that dietary factors are involved in irritable bowel syndrome (IBS), but the role of diet was evaluated mostly based on food frequency questionnaire. Whether food categories, quantity per time, and intake frequency are different between IBS patients and non-IBS individuals has not been clearly clarified.

AIM

To explore differences in dietary habits of people with vs without IBS and their correlation with symptom and psychological status.

METHODS

A total of 220 questionnaires were administered in a community population and the Rome IV criteria was applied to diagnose IBS. The dietary questionnaire used in this study was multidimensional from food categories, quantity per time, and intake frequency, in contrast to "yes or no" classification used in previous studies. Questionnaires including IBS symptom severity scale (IBS-SSS), IBS quality of life, visceral sensitivity index, hospital anxiety and depression score (HADS), and gastrointestinal symptom rating scale were used to assess the participants. Rank sum test was used to compare the quantity per time and intake frequency between IBS patients and non-IBS participants. The correlation between psychological factors and diet was evaluated by Spearman correlation analysis. Logistic regression analysis was used to assess the possible dietary risk factors for IBS.

RESULTS

In total, 203 valid questionnaires were collected (response rate 92.3%). Twenty-five participants met the Rome IV criteria for IBS, including 15 (60.0%) women and 10 (40.0%) men. Compared with the non-IBS group, the quantity per time and intake frequency of soybean and its products, spicy food, and dry-fried nuts were statistically significant in IBS participants (P < 0.05). They were positively associated with IBS-SSS and HADS anxiety and depression scores (P < 0.05). Besides, seafood, soft drinks, vegetables, and fruits differed only in quantity per time. The intake frequencies of egg, barbecue, and coarse grain were statistically significant in IBS patients (P < 0.05). We also found that the frequency of soybean and its products (≥ 7 times/week, odds ratio = 11.613, 95% confidence interval: 2.145-62.855, P = 0.004) was an independent risk factor for IBS.

CONCLUSION

Both quantity per time and intake frequency, especially soybean, differ between IBS patients and non-IBS participants. Dietary habits might play potential roles in the pathophysiology of IBS.

Mechanisms of Food-Induced Symptom Induction and Dietary Management in Functional Dyspepsia

Functional dyspepsia (FD) is a common disorder of gut-brain interaction, characterised by upper gastrointestinal symptom profiles that differentiate FD from the irritable bowel syndrome (IBS), although the two conditions often co-exist. Despite food and eating being implicated in FD symptom induction, evidence-based guidance for dietetic management of FD is limited. The aim of this narrative review is to collate the possible mechanisms for eating-induced and food-related symptoms of FD for stratification of dietetic management. Specific carbohydrates, proteins and fats, or foods high in these macronutrients have all been reported as influencing FD symptom induction, with removal of 'trigger' foods or nutrients shown to alleviate symptoms. Food additives and natural food chemicals have also been implicated, but there is a lack of convincing evidence. Emerging evidence suggests the gastrointestinal microbiota is the primary interface between food and symptom induction in FD, and is therefore a research direction that warrants substantial attention. Objective markers of FD, along with more sensitive and specific dietary assessment tools will contribute to progressing towards evidence-based dietetic management of FD.