Slow, deep breathing intervention improved symptoms and altered rectal sensitivity in patients with constipation-predominant irritable bowel syndrome

Prospective Evaluation of Autonomic Function and Intestinal Blood Flow in Health and Irritable Bowel Syndrome Shows Differences Limited to Patients With Constipation Predominance

BACKGROUND

Autonomic dysfunction may contribute to symptom generation in irritable bowel syndrome (IBS), possibly driven by psychological morbidity and activation of the hypothalamic-pituitary-adrenal axis. Previous data are conflicting, perhaps due to lack of accounting for differential bowel patterns in IBS (constipation vs. diarrhea) or by diverse methodologies used to measure autonomic function. Our aim was to determine if autonomic response differed between IBS subtypes and healthy controls.

METHODS

Forty female volunteers (20 IBS and 20 healthy) underwent comprehensive autonomic testing, fasting and postprandially, and in response to cold pressor and deep breathing challenges. Pulse transit time (PTT) and ultrasound measurements of intestinal blood flow were used as measures of systemic and local autonomic function, respectively. Outcomes were adjusted for baseline psychological comorbidities and gastric emptying (measured concurrently with scintigraphy).

KEY RESULTS

Findings, confined to IBS patients with predominant constipation (IBS-C), included (1) lower fasting and a trend to larger postprandial increase in superior mesenteric artery end-diastolic velocity; (2) lower fasting PTT, suggesting higher sympathetic tone, but no difference in postprandial PTT change; and (3) attenuated increase in postprandial aortic peak systolic velocity. Response to systemic autonomic challenges did not differ between IBS and health. Some psychological factors mediated differences between groups in the fasting, but not postprandial, state.

CONCLUSIONS AND INFERENCES

IBS-C patients display systemic and local autonomic imbalance providing some support for recent therapies aimed at modulating autonomic state specifically in this patient group (e.g., acustimulation).

Efficacy and Safety of Transcutaneous Auricular Vagus Nerve Stimulation in Patients With Constipation-Predominant Irritable Bowel Syndrome: A Single-Center, Single-Blind, Randomized Controlled Trial

INTRODUCTION

Transcutaneous auricular vagus nerve stimulation (taVNS) is a promising therapy for irritable bowel syndrome (IBS). The aims of this clinical trial were to evaluate the influence of taVNS on autonomic functions, rectal sensation, and acetylcholine (Ach) levels and to explore potential mechanisms involving gut microbiota and metabolic profiles.

METHODS

This study was a single-center, single-blind, randomized controlled trial executed at the First Affiliated Hospital of USTC, Anhui, China. Individual patients' constipation-predominant IBS (IBS-C)-related symptoms and mental health were assessed and scored using questionnaires at baseline and at week 4. Levels of serum Ach and nitric oxide, anorectal manometry, and heart rate variability were assessed both before and after the therapy. Fecal samples from each group were assessed to compare the gut microbiota, short-chain fatty acids, and gut microbiota-derived tryptophan metabolites.

RESULTS

Between September 2023 and May 2024, 40 patients (n = 20 in both taVNS and sham-taVNS groups) completed the 4-week study by performing an intention-to-treat analysis. No differences in all parameters between taVNS and sham-taVNS groups at the baseline were found. The taVNS significantly improved the visual analog scale score ( P < 0.001), IBS Severity Scoring System score ( P < 0.001), weekly frequency of spontaneous bowel movements ( P < 0.001), weekly frequency of complete spontaneous bowel movements ( P = 0.004), Bristol Stool Form Scale score ( P < 0.001), Hamilton Anxiety Scale score ( P < 0.001), Hamilton Depression Scale score ( P < 0.001), and IBS Quality of Life score ( P < 0.001). Furthermore, taVNS improved rectal sensation in patients with IBS-C, including improvements in the threshold volume for initial sensation ( P = 0.033), urge to defecate ( P = 0.022), and rectoanal inhibitory reflex ( P = 0.002). Moreover, taVNS elevated serum levels of Ach ( P = 0.005) and reduced nitric oxide ( P = 0.016) while also enhancing vagal activity ( P < 0.001) as determined by spectral analysis of heart rate variability. Three patients in the taVNS group and 2 in the control group had adverse consequences, which were manageable. In addition, taVNS led to a significant rise in the level of the genus Bifidobacterium ( P = 0.038) and increased levels of acetic ( P = 0.003), butyric ( P = 0.011), and propionic ( P = 0.005) acids. It also decreased tryptophan metabolism content, including 3-hydroxyanthranilic acid ( P = 0.007), anthranilic acid ( P = 0.026), and L-tryptophan ( P = 0.002).

DISCUSSION

The study manifested that noninvasive taVNS effectively improved constipation and abdominal pain symptoms in patients with IBS-C. The alleviation of IBS-C symptoms may be attributed to the integrative effects of taVNS on rectal functions, mediated through vagal, cholinergic, and multiomics mechanisms.

Research on the mechanism of core acupoints in electroacupuncture for functional constipation based on data mining and network acupuncture

Aim

Functional Constipation (FC) is a common gastrointestinal disorder that imposes a considerable strain on global health. It negatively impacts the quality of life and results in significant healthcare expenditures. Current treatments, such as lifestyle changes and medications, fail to meet patient satisfaction due to efficacy and safety issues. Electroacupuncture (EA), with its precise stimulation control and standardized protocols, shows promise in FC management. However, optimal EA parameters for FC treatment are yet to be established. Our study reviews EA applications in FC to inform a standardized treatment approach and explore EA's therapeutic mechanisms.

Methods

This comprehensive study utilized research literature from databases including PubMed, Embase, OVID, Web of Science, the Cochrane Library, CNKI, VIP, and Wanfang to perform a descriptive analysis of acupoint selection and EA parameters. It proceeded to analyze high-frequency acupoint groupings and stimulus parameters, followed by the excavation and analysis of core acupoint prescriptions. Subsequent steps integrated potential target identification for these core formulas, the assembly of a "core acupoint-prescription-target-constipation" network, and the construction of a protein-protein interaction (PPI) network to extract central targets. Additionally, Gene Ontology (GO) and KEGG enrichment analyses were conducted to prognosticate the underlying mechanisms by which EA may exert its therapeutic effects on FC.

Results

In our study, we analyzed 141EA prescriptions for FC and identified a core set of acupoints including Tianshu (ST25), Fujie (SP14), Shangjuxu (ST37), and Zusanli (ST36) through data mining. The frequency of use was highest for Tianshu (ST25) with 119 occurrences, followed by Fujie (SP14) with 59, Shangjuxu (ST37) with 42, and Zusanli (ST36) with 23. PPI network analysis revealed key targets such as NFKB1, IL6, MyD88, TLR4, TNF, TLR2, and IL1B. GO and KEGG analyses of 49 constipation-associated targets identified 257 BP, 37 CC, and 41 MF terms, and 154 significant pathways, with the top 20 visualized for further analysis.

Conclusion

The core acupoint prescription of EA for FC can exert its therapeutic effects by acting on multiple targets and pathways synergistically especially on NFKB1, IL6, MyD88, TLR4, TNF, TLR2, and IL1B. The research findings have preliminarily validated the fundamental effects and related mechanisms of EA parameters and core prescriptions, providing direction for further in-depth exploration of the mechanisms of action.

A primer for the gastroenterology provider on psychosocial assessment of patients with disorders of gut-brain interaction

BACKGROUND

GI-specific psychological factors are important contributors to patients' symptom experience and quality of life across all disorders of gut-brain interaction (DGBI). Clinicians' ability to recognize the role of these psychological factors is essential for formulating a biopsychosocial case conceptualization and informing treatment decisions.

PURPOSE

This article will familiarize gastroenterology providers with conceptualizing the role of GI-specific psychological factors in DGBI and provides stepwise, practical guidance for how to assess these during clinical encounters in a time-efficient manner.

Potential effects of sodium hyaluronate on constipation-predominant irritable bowel syndrome

Treatment strategies for constipation-predominant irritable bowel syndrome (IBS-C) continue to improve. However, effective drugs are still lacking. Herein, we explored whether sodium hyaluronate (SH) could be used to treat IBS-C. The effects of SH with different molecular weights were compared in a rat model of IBS-C. Low-molecular-weight SH (LMW-SH, 5 ∼ 10 kDa), medium-molecular-weight SH (MMW-SH, 200 ∼ 400 kDa), and high-molecular-weight SH (HMW-SH, 1300 ∼ 1500 kDa) were screened for efficacy in IBS-C using the following indicators: body weight, number of fecal pellets, fecal moisture, visceral hypersensitivity, and gastrointestinal transit rate. H-HMW-SH was the most effective in improving IBS-C symptoms. The ELISA kits indicated that H-HMW-SH reduced the levels of pro-inflammatory cytokines IL-1β, IL-18, and TNF-α in IBS-C rats. In addition, both western blot and immunofluorescence analyses showed that H-HMW-SH increased the protein expressions of claudin-1, occludin and zonula occludens-1. Furthermore, H-HMW-SH restored the balance of intestinal flora in different intestinal contents (duodenum, jejunum, ileum, and colon) and feces of rats with IBS-C. Overall, our study illustrates the therapeutic potential of H-HMW-SH in the treatment of IBS-C.

Effect of Pilates exercises on symptoms of irritable bowel syndrome in women: a randomized controlled trial

Objective

The treatment of irritable bowel syndrome (IBS) is challenging, calling for therapeutic strategies other than pharmacological treatment. Therefore, this study aimed to investigate the effects of Pilates exercises on IBS symptoms and severity, frequency of complete spontaneous bowel movements, fatigue, anxiety, depression, and body weight in women with IBS.

Methods

Sixty women with IBS, aged 20-45, completed this study. They were randomly assigned to two equal groups: a study group (n = 30) and a control group (n = 30). The study group received an 8-week Pilates exercise program (2 sessions per week) in addition to dietary advice, while the control group received dietary advice only. Inclusion criteria were women, IBS diagnosed based on Rome IV Diagnostic criteria, constipation-predominant IBS, and moderate to severe IBS. The outcome measures were the IBS severity scoring system (IBS-SSS), the frequency of complete spontaneous bowel movements, the modified fatigue impact scale (MFIS), hospital anxiety and depression (HADS) scale, and body weight (BW).

Results

The study group showed more significant improvements than the control group in total IBS-SSS score (Cohen d = 0.73, p < 0.001), frequency of complete spontaneous bowel movements (Cohen d = 0.50, p < 0.001), total MFIS score (Cohen d = 0.74, p < 0.001), anxiety (Cohen d = 0.56, p < 0.001), and depression (Cohen d = 0.64, p < 0.001). The study group also showed a significant reduction in body weight compared to baseline (p < 0.05). The control group showed significant improvements in all outcomes, except body weight, compared to baseline (p < 0.05).

Conclusion

Pilates exercises, used in addition to dietary advice, may significantly improve IBS symptoms and severity, frequency of complete spontaneous bowel movements, and alleviate fatigue, anxiety, and depression moderately more than dietary advice alone in women with constipation-predominant IBS. Nevertheless, dietary advice alone may also significantly improve these outcomes in this cohort.