Staple foods consumption and irritable bowel syndrome in Japanese adults: a cross-sectional study

A systematic review and meta-analysis of diet and nutrient intake in adults with irritable bowel syndrome

BACKGROUND

Numerous individual and environmental factors including diet may play an important role in the pathophysiology of irritable bowel syndrome (IBS). It is unclear to what degree dietary intake is affected in individuals with IBS. We aimed to perform a systematic review and meta-analysis to summarize dietary intake of adults with IBS and to compare dietary intake between adults with IBS and non-IBS controls.

METHODS

Ovid MEDLINE, Embase, Cochrane, CINAHL, and Scopus were searched through February 2023 for clinical trials and observational studies measuring usual diet in adults with IBS. Pooled weighted averages were estimated for total energy, macronutrient, and micronutrient data. Mean differences (MD) in nutrient intake were estimated for adults with IBS versus non-IBS controls using a random effects model. Heterogeneity was assessed by the inconsistency index (I2).

KEY RESULTS

Sixty-three full-text articles were included in the review of which 29 studies included both IBS and control subjects. Nutrients not meeting the recommended intake level for any dietary reference values in the IBS population were fiber and vitamin D. Meta-regression by female proportion was positively correlated with total fat intake and negatively correlated with carbohydrate intake. Comparisons between participants with IBS and controls showed significantly lower fiber intake in participants with IBS with high heterogeneity (MD: -1.8; 95% CI: -3.0, -0.6; I2 = 85%).

CONCLUSIONS AND INFERENCES

This review suggests that fiber and vitamin D intake is suboptimal in IBS; however, overall dietary intake does not appear to be comprised. Causes and consequences of reduced fiber in IBS deserve further study. Results of this systematic review and meta-analysis suggest that fiber and vitamin D intake is suboptimal in IBS. However, overall intake of other macro- and micronutrients does not appear to be compromised. Causes and consequences of reduced fiber and Vitamin D intake in IBS deserve further study.

Characteristics of disorders of gut-brain interaction in the Japanese population in the Rome Foundation Global Epidemiological Study

BACKGROUND

The aims were to use Japanese data from the Rome Foundation Global Epidemiological Study (RFGES) to test the hypotheses that severity of gastrointestinal (GI) symptoms and psychosocial disturbance are ordered as Rome IV irritable bowel syndrome (IBS) > Rome III IBS > DGBI, not IBS > others.

METHODS

Subjects were 2504 Japanese in the RFGES. We assessed DGBI/IBS diagnoses with Rome IV/III, IBS Symptom Severity Scale (IBS-SSS), Patient Health Questionnaire (PHQ) for anxiety/depression and non-GI somatic symptoms, PROMIS-10 for quality of life (QOL), Work Productivity and Activity Impairment (WPAI) Questionnaire, parts of Self-reported IBS Questionnaire (SIBSQ) for meal effect and stress effect, Food Frequency Questionnaire, and medication questions.

KEY RESULTS

The prevalence of Rome IV DGBI was as follows; IBS-C 0.5%, IBS-D 0.8%, IBS-M 0.8%, IBS-U 0.1%, unspecified functional bowel disorder 10.7%, postprandial distress syndrome 2.2%, and epigastric pain syndrome 0.3%. Rome III IBS prevalence; IBS-C 3.0%, IBS-D 3.1%, IBS-M 2.7%, and IBS-U 0.6%. Comparison among Rome IV IBS (n = 54), Rome III IBS (n = 197), other DGBI (n = 746), others (n = 1389) revealed significant order as Rome IV IBS > Rome III IBS > other DGBI > others in IBS-SSS, anxiety/depression, activity impairment, non-GI symptoms, physical QOL, mental QOL, exacerbated symptoms by meals and perceived stress (all p < 0.001).

CONCLUSIONS & INFERENCES

These findings support the study hypotheses. Data from Japan as a culturally homogenous country suggest Rome IV IBS is more severe and hence has more gut-brain psychobehavioral involvement than Rome III IBS.

Significant Differences in Gut Microbiota Between Irritable Bowel Syndrome with Diarrhea and Healthy Controls in Southwest China

BACKGROUND

Irritable bowel syndrome (IBS) is a heterogeneous disease, which is closely related to environmental factors and gut microbiota.

OBJECTIVE

To study gut microbiota in IBS-D of Han nationality in Southwest China and explore its relationship with environmental factors.

METHODS

One hundred and twenty cases of IBS-D and 63 cases of HCs were recruited; baseline data such as age, height, and weight were collected. HAMA, HAMD, IBS-SSS, IBS-QOL, and laboratory tests were performed. Feces were collected for 16S rDNA sequencing. Then, the differences of gut microbiota were analyzed and looked for biomarkers of each. FAPROTAX was used to predict the functional differences of gut microbiota. Spearman analysis was conducted between the phylum level and environmental factor.

RESULTS

There were significant differences in daily life between IBS-D and HCs, especially in the spicy taste. The scores of HAMA and HAMD, urea, and transaminase in IBS-D were significantly higher than those of HCs. The richness of gut microbiota in IBS-D was significantly lower than that of HCs, as well as the beta diversity, but not diversity. The biomarkers of IBS-D were Prevotella, Clostridiales, and Roseburia, and the biomarkers of HCs were Veillonellaceae, Bacteroides coprocola, and Bifidobacteriales. The functions of gut microbiota in IBS-D were significantly different from HCs. Correlation analysis showed that multiple gut microbiota were closely related to HAMA, IBS-SSS, IBS-QOL, inflammatory indexes, and liver enzymes.

CONCLUSION

There are significant differences in richness of gut microbiota, flora structure, and flora function between IBS-D and HCs in Southwest China. These differences may be closely related to environmental factors such as eating habits, living habits, and mental and psychological factors.

CLINICAL TRIAL REGISTRATION

The trial was registered and approved in China Clinical Trial Registry (Registration No. ChiCTR2100045751).

Systematic Review of Human and Animal Evidence on the Role of Buckwheat Consumption on Gastrointestinal Health

BACKGROUND

Buckwheat is a commonly cultivated crop with growing evidence that it is beneficial to gastrointestinal (GI) health. This systematic review summarizes the role of buckwheat in modifying GI health outcomes and microbiomes.

METHODS

Four medical databases and Google Scholar were systematically searched. Clinical trials, observational studies, animal in vivo, and in vitro studies with human and animal GI-derived samples were included.

RESULTS

There were 32 studies (one randomized controlled trial [RCT], one non-randomized trial, 3 observational, 9 in vitro, and 18 animal in vivo studies) included. In preclinical studies, buckwheat extracts were observed to have cytotoxic potential against human-derived GI cancer cell lines. Animals fed with buckwheat had lower GI mucosal inflammation, higher alpha diversity in the GI microbiome, and higher levels of fecal short-chain fatty acids. Human evidence studies and clinical trials were limited and predominantly of moderate risk of bias. The majority of in vitro studies with GI-derived samples and in vivo studies were reliable without restrictions in study design.

CONCLUSION

In vivo and in vitro studies show that buckwheat may have potential GI benefits due to its anti-oxidant and anti-inflammatory potential; however, human evidence remains limited, and its impact on health in humans remains to be elucidated in future trials.

Nutritional status in irritable bowel syndrome: A North American population-based study

Background and Aim

Irritable bowel syndrome (IBS) affects 12% of the population, and the evidence supporting current medical interventions is poor. There is increasing focus on the therapeutic benefit of diet and supplementation. We aim to compare dietary composition and hematologic and biochemical markers in those with and without IBS to determine potential targets for therapeutic supplementation.

Methods

All 17 national surveys between 1959 and 2019 were screened, and only 1, the Second National Health and Nutrition Examination Survey (NHANES II) (1976–1980), provided comprehensive data on IBS. We performed a cross‐sectional analysis of hematologic and biochemical markers and dietary composition of 12 295 individuals, aged 18–74, in NHANES II.

Results

Individuals with IBS had significantly higher copper–zinc ratios (1.70 vs 1.55, P = 0.048) and were more likely to have ratios above 1.8 (odds ratio 1.79, 95% confidence interval 1.02–3.13), indicative of underlying copper–zinc imbalance. While more likely to report dietary avoidances, they had no other evidence of nutritional deficiencies. In addition, dietary recall showed that those with IBS consumed more calories (P = 0.02), were more likely to take vitamin supplements (P = 0.003), and that their macro and micronutrient intake was not significantly different.

Conclusions

The findings suggest that individuals with IBS should be screened for copper–zinc imbalance. Given zinc's role in the immune system, the “brain–gut” axis, and the gastrointestinal barrier, the identified copper–zinc imbalance may play a role in perpetuating the underlying pathophysiology of IBS. Further studies are needed to investigate this hypothesis and the potential role of therapeutic zinc supplementation.

Food consumption and dietary intakes in 36,448 adults and their association with irritable bowel syndrome: Nutrinet-Santé study

INTRODUCTION

Diet plays an important role for patients with irritable bowel syndrome (IBS). The aim of this study was to compare the diets in terms of food consumption and nutrient intake between subjects with IBS and controls in a large French population.

METHODS

This study included 36,448 subjects from the Nutrinet-Santé cohort study, who completed a questionnaire pertaining to functional bowel disorders based on the Rome III criteria. Dietary data were obtained from at least three self-administered 24 h records via the internet. Association between IBS and diet was evaluated by comparison tests controlled for gender, age and total energy intake (ANCOVA tests).

RESULTS

Subjects included were mainly women (76.9%) and the mean age was 50.2 ± 14.2 years. Among these individuals, 1870 (5.1%) presented with IBS. Compared to healthy controls, they had significantly lower consumption of milk (74.6 versus 88.4 g/day; p < 0.0001), yogurt (108.4 versus 115.5 g/day; p = 0.001), fruits (192.3 versus 203.8 g/day; p < 0.001), and higher soft non-sugared beverages (1167.2 versus 1122.9 ml/day; p < 0.001). They had higher total energy intake (2028.9 versus 1995.7 kcal/day; p < 0.001), with higher intakes of lipids (38.5 versus 38.1% of total energy intake; p = 0.001) and lower intakes of proteins (16.4 versus 16.8% of total energy intake; p < 0.0001), as well as micronutrients (calcium, potassium, zinc and vitamins B2, B5 and B9, all p < 0.0001).

CONCLUSIONS

In this large sample, these findings suggest that dietary intake of subjects suffering from IBS differs from that of control subjects. They may have adapted their diet according to symptoms following medical or non-medical recommendations.

Smoking in Irritable Bowel Syndrome: A Systematic Review

OBJECTIVE

The aim of this review was to examine (1) the prevalence of smoking in subjects with irritable bowel syndrome (IBS), (2) whether smoking prevalence significantly differs between subjects with and without IBS, and (3) whether smoking significantly predicts the presence or the development of IBS.

METHODS

Articles were retrieved by systematically searching the Scopus, Web of Science, and PubMed electronic databases from inception to July 2016, using the keywords "smoking" and "tobacco" combined with "irritable bowel syndrome." Reference lists of included articles were also searched. Articles were included if they (1) reported data on smoking prevalence in subjects with IBS and/or on the association (assessed by means of multivariate analyses) between smoking and IBS, (2) identified IBS according to Manning criteria or Rome I-III criteria, (3) were English-language articles, and (4) involved only adult subjects.

RESULTS

The electronic searches yielded a total of 1,637 records, and 42 articles met inclusion criteria. Another 13 articles were retrieved through manual search, leading to a total of 55 included articles. Smoking prevalence in subjects with IBS was assessed by 48 articles and ranged from 0% in university students to 47.1% in patients with microscopic colitis. Thirty-three articles compared smoking prevalence between subjects with and without IBS. In 25 articles no significant difference was found. In seven articles smoking was significantly more frequent in subjects with IBS compared to those without IBS, while one study found a significantly higher smoking prevalence in controls. Eighteen multivariate analyses assessing the association between smoking and IBS were presented in 16 articles. Only one study employed a prospective design. In 11 analyses, smoking was not significantly associated with IBS after adjusting for covariates. In seven studies smoking independently predicted the presence of IBS.

CONCLUSIONS

According to the selected articles, a significant association between smoking and IBS cannot be confirmed. However, different shortcomings may hinder generalizability and comparability of many studies. A dimensional assessment of smoking, a prospective design, the differentiation between IBS subgroups, and the recruitment of patients in clinical settings, especially in primary care, are necessary to clarify the role of smoking in IBS.