Introduction

Irritable bowel syndrome (IBS) is the most common disorder of gut-brain interaction (DGBI) and associated with other pain syndromes, lifetime stress, and psychological disorders. During the last years, associations have also been described between IBS and overweight and the metabolic syndrome. Low content of fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) and a starch- and sucrose-reduced diet (SSRD) reduce IBS symptoms (1,2). However, concerns have been raised whether a diet may lead to malnutrition when adhered to for a longer time.

Aims & Methods

The aim of the study was to randomize IBS patients according to Rome IV with a total score of IBS-SSS > 175 to either SSRD or low FODMAP and measure nutritional status over time. 155 patients, 131 women (84.5%), age 42 (32-55) years, weight 69.2 (63.0-82.9) kg, BMI 25 (23-28) kg/m² were included. 77 received SSRD (5 dropouts) and 78 low FODMAP (6 dropouts) for 4 weeks, with a second follow-up at week 24. Rome IV, IBS-severity scoring system (IBS-SSS) and visual analog scale-IBS were completed at baseline, and after 4 and 24 weeks. Nutritional status, lipid profile, and glycosylated hemoglobin A1c (HbA1c) were analyzed in blood according to clinical routines at the laboratory. Differences were calculated by Wilxon Signed Ranks with values at week 4 and 24 in comparison with baseline. P<0.05 was considered statistically significant.

Results

There were no differences in baseline values between the groups. All gastrointestinal and extraintestinal symptoms were improved by both diets (p<0.001 in most variables). The weight reduction was most pronounced in SSRD. At week 4, folate was increased (p=0.003), and iron decreased (p=0.001), in the SSRD group, whereas vitamin D was increased in both groups (p=0.004 vs. p=0.017) and HbA1c was decreased (p=0.010 vs. p=0.009). The only negative nutritional measurement at week 24 was lower cobalamin levels in both groups (p=0.009 vs. p=0.002) and lower ferritin in the low FODMAP group (p=0.007). Cholesterol, low-density lipoprotein (LDL) cholesterol, and non-high-density lipoprotein (non-HDL) cholesterol were decreased throughout the study in the SSRD group, but only after 4 weeks in the low FODMAP group (Table).

Conclusion

Both SSRD and low FODMAP decrease gastrointestinal and extraintestinal symptoms. Although some nutritional analyses showed lower values after the intervention, other showed improved values. Metabolic risk factors such as weight, lipid values and HbA1c were improved by the diets, especially SSRD. Thus, dietary interventions in IBS do not only improve symptoms but also improve lipid and glycemic profiles without any major impact on nutritional status when the IBS patients are followed for 6 months. Reducing carbohydrate intake appears to positively impact bowel symptoms and metabolism in IBS patients, irrespective of the specific carbohydrates targeted by the corresponding diet. Future studies are warranted to identify the individual saccharides most likely to exert therapeutic effects, eventually in relation to their breakdown capacity in individual patients.

References

Mitchell H, Porter J, Gibson PR, Barrett J, Garg M. Review article: implementation of a diet low in FODMAPs for patients with irritable bowel syndrome-directions for future research. Aliment Pharmacol Ther. 2019 Jan;49(2):124-139.
Nilholm C, Roth B, Ohlsson B. A Dietary Intervention with Reduction of Starch and Sucrose Leads to Reduced Gastrointestinal and Extra-Intestinal Symptoms in IBS Patients. Nutrients. 2019 Jul 20;11(7):1662.

Introduction

The low FODMAP diet (LFD) is an efficacious dietary intervention for reducing symptoms in patients with irritable bowel syndrome (IBS). Although effective, the LFD is complex, requires guidance from a trained dietitian and may be associated with decreased caloric intake and weight loss. A less strict diet intervention, by a self-guided smartphone application (FODMAP-light DOMINO app), showed superiority compared to standard medical therapy in primary care IBS patients¹. The efficacy of the FODMAP-light app in tertiary care patients has not been evaluated.

Aims & Methods

We aim to evaluate the efficacy of the FODMAP-light app for managing IBS in tertiary care. To this end, we assessed its impact on IBS symptoms, nutritional intake and psychosocial comorbidities.
After a two-week baseline period, IBS patients were instructed to follow the FODMAP-light diet app during eight weeks. A symptom diary, including the Bristol stool scale (BSS), was filled out daily. IBS symptoms were scored on a 0-100mm Likert scale. Stool consistency was reported as days per BSS types (1-7) over two weeks. Seven-day food diaries were collected during baseline and diet period. Questionnaires to assess IBS symptom severity (IBS-SSS) and psychosocial comorbidities (PHQ and GAD-7) were filled out at baseline and after diet. Data are reported as mean±SD or median (IQR).

Results

Among 53 patients with IBS (81% female, age 32 (28-42) years, BMI 23 (20-29) kg/m²), the diet significantly reduced IBS-SSS (287±72 vs. 172±91, p < 0.0001) with an 81% responder rate (≥50 points improvement). Compared to baseline, duration (41 (30-54) vs. 17 (7-31)) and severity (39 (26-52) vs. 14 (6-33)) of abdominal pain, bloating (44 (27-55) vs. 19 (8-31)), flatulence (46 (29-57) vs. 18 (9-30)), and impact on daily life (38 (24-51) vs. (16 (6-37)), significantly improved during the diet (all p < 0.0001). Stool frequency remained unchanged, but there was a significant shift from loose (BSS type 6 and 7) to normal stools (BSS type 2,3 and 4) (p < 0.0001), and episodes of urgency significantly decreased (p < 0.01). Nutritional analysis, shown in table 1, revealed a decreased caloric intake (∆-186.1 kcal/d, p < 0.0001), but no weight loss. Intake of FODMAPs decreased significantly, except for lactose and mannitol. Psychosocial outcomes improved significantly, with reduction in somatization (11 (8–14) vs. 8 (6-12), p < 0.0001), depression (5 (3–11) vs. 4 (2–6), p < 0.0001), and anxiety (6 (3–9) vs. 4 (1–6), p < 0.001).

Conclusion

The DOMINO FODMAP-light app is an effective treatment option for improving gastrointestinal as well as psychosocial factors in tertiary care IBS, providing a promising alternative to more restrictive dietary approaches.

References

1 Carbone F and Van den Houte K et al. Gut. 2022

Introduction

A diet with low content of fermentable oligo-, di-, and monosaccharides and polyols (FODMAP) are established treatment for irritable bowel syndrome (IBS), with well-documented efficiency. Recently, a starch- and sucrose-reduced diet (SSRD) has shown similar promising effects.

Aims & Methods

This randomized, non-inferiority study aimed to test SSRD against low FODMAP and compare the responder rates to a 4-week dietary intervention of either diet.
The 155 IBS patients were randomized to SSRD (n=77) or low FODMAP (n=78) for 4 weeks, with a follow-up 20 weeks later. The SSRD advice means removal of sucrose and reduction of starch-containing food such as cereals, some vegetables (e.g., potatoes), rice, and pasta, with maintained gluten and lactose. Low FODMAP means reduction of fermentable saccharides and polyols. The questionnaires Rome IV, IBS-severity scoring system (IBS-SSS), and visual analog scale for IBS (VAS-IBS) were completed at baseline and after 2, 4, and 24 weeks. Weight, height, waist circumference, and blood pressures were measured at week 2, 4, and 24. Comparisons were made within the groups and the differences between the changes in the two groups were compared.

Results

The patients were categorized according to the Rome IV criteria as constipation-predominated IBS (IBS-C) (n=26, 16.8%), diarrhea-predominated IBS (IBS-D) (n=44, 28.4%), mixed IBS (IBS-M) (n=54, 34.8%), unspecified IBS (IBS-U) (n=7, 4.5%), and unspecific functional bowel disorder (FBD) (n=24, 15.5%) with weekly abdominal pain but weak association between the pain and bowel habits. There were no differences between the groups at baseline. In the SSRD group, 72 (93.5%) completed the study at week 4 and 53 (68.8%) at week 24, with corresponding figures 72 (92.3%) and 49 (62.8%) in low FODMAP. The responding rate (RR=∆Total IBS-SSS ≥ −50) was non-inferior in SSRD compared with low FODMAP at week 2 (84.7% vs. 81.4%); p=0.658), week 4 (84.7% vs. 84.7%; p=1.00), and week 24 (52.8% vs. 68.0%; p=0.159). All gastrointestinal and extraintestinal symptoms were equally improved (p<0.001 in most variables) after the 4-week intervention. This remained at week 24 for all specific abdominal symptoms, total IBS-SSS, total extraintestinal IBS-SSS, and most specific extraintestinal symptoms. The decrease in total IBS-SSS correlated at all time points with the decrease of total extraintestinal symptoms (p<0.001) and improved psychological well-being (p<0.001). At week 4, 26.4% in both groups were considered healthy with <75 in total IBS-SSS. At week 24, around 40-50% had abominal pain 2-3 times a month, or less, or did have <75 in total IBS-SSS. SSRD rendered more pronounced reductions in weight (p=0.006), body mass index (BMI) (p=0.005), and sugar craving (p=0.05) compared with low FODMAP, whereas waist circumference and blood pressure were equally decreased in both groups. Weight and BMI were regained at follow-up. The decrease in total IBS-SSS at week 24 correlated with the decrease of weight (p=.010) and BMI (p=0.013), and the responders at week 24 in the SSRD group still had lowered weight (-0.7 (-2.5-0.1) vs. 0.2 (-0.7-2.2) kg; p=0.005) and BMI (-0.25 (-0.85-0.03) vs. 0.07 (-0.35-0.77) kg/m²; p=0.009) compared with baseline in contrast to non-responders. Those who had tested both diets preferred SSRD (p=0.032).

Conclusion

The SSRD effect on gastrointestinal and extraintestinal IBS symptoms were not inferior to the low FODMAP effect. Reductions of weight, BMI, and sugar craving were most pronounced following SSRD. Thus, dietary intervention in IBS do not only affect symptoms but also anthropometric parameters.

Disclosure

Nothing

Introduction

The pathogenesis of irritable bowel syndrome with constipation (IBS-C) remains unclear. Several studies reported that gut dysbiosis had been observed in IBS patients. The treatment of IBS mostly focuses on symptomatic therapy. Acupuncture is one of the alternative therapies for IBS symptoms. However, the effects of acupuncture on symptoms and gut microbiota profiles of IBS-C patients are still unclear. The present study aimed to determine the alterations of the gut microbiota profiles between IBS-C patients and healthy subjects as well as to investigate the effect of electroacupuncture (EA) on the alterations of the profiles of gut microbiota and IBS symptoms in IBS-C patients.

Aims & Methods

We aim to determine the alterations of the gut-brain-microbiota axis between IBS-C patients and healthy subjects and to investigate the effect of electroacupuncture on the alterations of the gut-brain-microbiota axis in IBS-C patients. Thirty-two participants were enrolled in the study, including 16 healthy participants, as the control group and 16 IBS-C patients. Clinical data, blood, and fecal samples were collected from all participants. Then, 16 IBS-C patients were treated with EA nine times for 1 month. Clinical data, blood, and feces were collected in those IBS-C patients at 2-time points: after the end of EA and 1-month follow-up.

Results

Irritable bowel syndrome symptoms severity scale scores (IBS-SSS) and Irritable bowel syndrome quality of life (IBS-QoL) of IBS patients were significantly greater than the control group. There was no significant difference in cognition and depression scores in Hospital Anxiety and Depression Scale (HADs) between the control and the IBS-C groups. A significant increase in serum cortisol level in the IBS-C group was observed when compared to controls. Clinical outcomes of IBS symptoms were significantly improved after EA. These significances were also found in the 1-month follow-up. There was no significant change in serum cortisol levels following EA therapy. Regarding gut microbiota profiles, alpha diversity was not different between the four groups: control, IBS-C, after EA treatment, and 1-month follow-up. However, the beta diversity was significantly different among groups. The beta diversity used of PERMANOVA analysis showed a significant difference between the controls and IBS-C patients (PERMANOVA q-value < 0.05 in Bray-Curtis, Jaccard, and unweighted UniFrac distances). Immediately after EA therapy in IBS-C patients, the beta diversity showed no difference between pre- and post-treatment. Interestingly, the cluster of gut microbiota profiles shifted away from the IBS group and was similar to the control group after a 1-month follow-up.​

Conclusion

Our findings demonstrated the differences in profiles of gut microbiota profiles between IBS-C patients and healthy, and EA treatment showed the benefit of improving clinical outcomes and profiles of gut microbiota.

References

Chang L, Sundaresh S, Elliott J, Anton P, Baldi P, Licudine A, et al. Dysregulation of the hypothalamic‐pituitary‐adrenal (HPA) axis in irritable bowel syndrome. Neurogastroenterology & Motility. 2009.
Chen Y, Zhao Y, Luo D-n, et al. Electroacupuncture regulates disorders of gut-brain interaction by decreasing corticotropin-releasing factor in a rat model of IBS. Gastroenterology research and practice. 2019.
Tan L-h, Li K-g, Wu Y-y, et al. Effect of electroacupuncture at different acupoints on the expression of NMDA receptors in ACC and colon in IBS rats. Evidence-Based Complementary and Alternative Medicine. 2019.
Tap J, Derrien M, Törnblom H, Brazeilles R, Cools-Portier S, Doré J, et al. Identification of an intestinal microbiota signature associated with severity of irritable bowel syndrome. Gastroenterology. 2017.
Labus JS, Osadchiy V, Hsiao EY, et al. Evidence for an association of gut microbial Clostridia with brain functional connectivity and gastrointestinal sensorimotor function in patients with irritable bowel syndrome, based on tripartite network analysis. Microbiome. 2019.
Song Y-F, Pei L-X, Chen L, et al. Electroacupuncture relieves irritable bowel syndrome by regulating IL-18 and gut microbial dysbiosis in a trinitrobenzene sulfonic acid-induced post-inflammatory animal model. The American journal of Chinese medicine. 2020.
etc.

Disclosure

The authors declared that they have no conflicts of interest.

Introduction

The interdisciplinary Bergen BrainGut study was designed to stratify the complex interaction between the brain, gut and microbiota in patients with irritable bowel syndrome (IBS) (1). Some bacterial species have a critical function in the gut and a functional bacterial profile is useful to identify potential dysfunction when there are observations of deviation from expected normal abundance (Table 1).

Aims & Methods

In this in-depth sub-study we aimed to assess the functional bacterial profile and dysbiosis in patients with IBS compared to healthy controls (HCs), and investigate changes in the patients after a dietitian-led strict 12-week low FODMAP diet (LFD). Sixty patients with Rome IV-confirmed IBS (mean age 38 years, 46 (77%) females) with moderate to severe symptoms (IBS-SSS > 175), and 42 HCs (mean age 35 years, 27 (64%) females) were included. Participants answered IBS Symptom Severity Scale (IBS-SSS) and delivered fecal samples at baseline (IBS and HC) and 12 weeks post LFD (IBS only). Functional bacterial profiles were assessed by GA-map^TM Dysbiosis Test Lx® based on 16s rRNA sequence of bacterial species or groups (Table 1). Patients were classified as LFD responders if they had a ≥ 50-point reduction in IBS-SSS from pre to post LFD. Dysbiosis was classified as dysbiosis index (DI) > 2 (range 0-5).

Results

Twenty-one patients were classified as IBS-D (diarrhea), 31 IBS-M (mixed diarrhea and constipation) and eight IBS-C (constipation). Thirty-six patients with IBS-M and IBS-D completed the 12-week LFD. At baseline, the relative frequency of dysbiosis was higher in IBS (24.6%) compared to HCs (5.6%, p = .023), but no significant difference in functional bacterial profile was observed between the groups. In week 12, patients showed a significant reduction in symptom severity (IBS-SSS, p < .005) and a significant increase in dysbiosis (BL: 17.6% vs week 12: 58.8%, p < .001). Eighty percent (n = 28) were classified as responders, but no significant change in functional bacterial profile from pre to post LFD was observed for this group, nor between responders and non-responders post LFD.

Table 1. Description of functional bacterial profiles. Modified table from ga-map.com.

Conclusion

Although the literature suggests a different bacterial profile in IBS compared to healthy controls, our results provide no evidence for a difference in functional bacterial profile between IBS and healthy controls, nor associations with changes in symptom severity score. However, the relative frequency of dysbiosis in patients with IBS increased after a 12-week strict low FODMAP diet as avoiding some of the high FODMAP food items in a long period might lead to missing their prebiotic effects in gut.

References

1. Berentsen B, Bharath HN, Lied GA et al. Study protocol of the Bergen brain-gut-microbiota-axis study: a prospective case-report characterization and dietary intervention study to evaluate the effects of dietary-induced microbiota signature-alterations on cognition and anatomical and functional brain connectivity in patients with irritable bowel syndrome. Medicine 2020;Vol;No(e21950).

Introduction

Response rates to the Low FODMAP Diet (LFD) in IBS vary and predictors of benefit remain poorly defined. While several studies from Western populations have identified microbial signatures linked to response, data from Asian cohorts remain limited.

Aims & Methods

This study aims to identify microbial predictors and longitudinal microbiome shifts in Asian IBS-D patients consuming a LFD. We recruited 20 adult Asian patients with IBS-D diagnosed according to the ROME-IV criteria. All subjects received LFD dietary advice from a dietitian at initiation and were followed-up for a total of 28-days. Clinical response was assessed by a ≥50-point improvement in the IBS Symptom Severity Score (IBS-SSS) from Day 0 (baseline) as compared to follow-up at Day 28. Stool samples were collected at baseline, Day 14, and Day 28. Microbial DNA was extracted using bead-beating and Qiagen PowerFecal kits, and the V3–V4 region of the 16S rRNA gene was amplified and sequenced on the Illumina MiSeq platform. Bioinformatic processing included denoising with DADA2, taxonomic assignment using the SILVA 138 database, and rarefaction to even sequencing depth. Microbiome metrics included alpha diversity (Shannon and Simpson), beta diversity (Bray-Curtis PCoA with PERMANOVA), and differential abundance testing with DESeq2.

Results

By Day 28, 11 of 20 patients (55%) achieved clinical response, with a median IBS-SSS reduction of 172 points (IQR: 88–248), compared to 24 points in non-responders (IQR: −11 to 55; p=0.003). Alpha diversity was not significantly different between groups, but responders exhibited a trend toward higher Shannon and Simpson diversity at baseline. Beta diversity analysis using Bray-Curtis dissimilarity revealed partial clustering by responder status (PERMANOVA p=0.06), and PCoA plots showed individual-specific shifts in community structure across time, indicating that the LFD induces personalized microbiome trajectories.
At baseline, responders had significantly higher relative abundances of butyrate-producing and anti-inflammatory genera, including Ruminococcus, Blautia, Eubacterium siraeum, and Bifidobacterium bifidum (adjusted p<0.05). These findings are consistent with prior reports, including Bennet et al. (2018) and Vervier et al. (2022), where such taxa were part of a “health-like” IBS-P (pathogen-enriched) to IBS-H (health-like) axis. The enrichment of Blautia and Ruminococcus is particularly noteworthy as these are established butyrate producers involved in maintaining colonic barrier function and reducing visceral hypersensitivity. By Day 28, differential abundance analysis revealed that responders exhibited increases in Ruminococcus bicirculans, Parabacteroides gordonii, and Weissella cibaria. In contrast, non-responders showed persistence or increases in taxa such as Tyzzerella and Olsenella, which have been associated with inflammation or IBS severity in prior studies (Chuah et al., 2024).

Conclusion

This study provides novel microbiome insights from an underrepresented Asian IBS population consuming a LFD. Despite dietary and baseline microbiota differences from Western populations, we observed remarkably consistent microbiome predictors of response, including higher baseline levels of butyrate-producing taxa and favorable microbial restructuring during the intervention. These results reinforce the reproducibility and functional relevance of microbiome predictors in IBS dietary therapy, and support microbiome profiling as a potential tool for personalized dietary guidance across a diverse global population.

References

Bennet SMP et al. Multivariate modelling of faecal bacterial profiles of patients with IBS predicts responsiveness to a diet low in FODMAPs. Gut. 2018 May;67(5):872-881.
Vervier K et al. Two microbiota subtypes identified in irritable bowel syndrome with distinct responses to the low FODMAP diet. Gut. 2022 Sep;71(9):1821-1830.
Chuah KH, Mahadeva S. Can we predict who will respond to a low-FODMAP diet in irritable bowel syndrome? J Gastroenterol Hepatol. 2024 Feb;39(2):217-218. ​