Hyperbaric oxygen therapy ameliorates TNBS-induced acute distal colitis in rats

Effects of Hyperbaric Oxygen Therapy for Clostridioides difficile-associated Colitis: A Retrospective Study

Objectives

Clostridioides difficile (CD) is an anaerobic spore-forming Gram-positive rod that is a major cause of antibiotic-associated diarrhea. Hyperbaric oxygen therapy (HBO) is a well-established treatment for Clostridium perfringens, but there are no reports that have examined the efficacy of HBO against CD, which is also an anaerobic bacterium.

Methods

In this study, we retrospectively examined whether HBO therapy affects the prognosis following CD infections (CDI). This study included 92 inpatients diagnosed with CDI at our hospital between January 2013 and December 2022. Of these, 16 patients received HBO therapy. The indications for HBO therapy were stroke in five patients, ileus in four patients, cancer in two patients, acute peripheral circulatory disturbance in two patients, and others in three patients. The mean observation period was 5.4 years.

Results

In the univariate analysis, there was no significant difference in severity, mortality, hospitalization, or overall survival between patients who did and did not receive HBO therapy. However, the HBO group had a significantly lower recurrence rate (0% vs. 22.4%, p=0.0363) and a shorter symptomatic period (6.2 vs. 13.6 days, p=0.0217).

Conclusions

HBO may have beneficial effect on CDI by shortening the symptomatic period and preventing recurrence.

The Mechanisms of Action of Hyperbaric Oxygen in Restoring Host Homeostasis during Sepsis

The perception of sepsis has shifted over time; however, it remains a leading cause of death worldwide. Sepsis is now recognized as an imbalance in host cellular functions triggered by the invading pathogens, both related to immune cells, endothelial function, glucose and oxygen metabolism, tissue repair and restoration. Many of these key mechanisms in sepsis are also targets of hyperbaric oxygen (HBO2) treatment. HBO2 treatment has been shown to improve survival in clinical studies on patients with necrotizing soft tissue infections as well as experimental sepsis models. High tissue oxygen tension during HBO2 treatment may affect oxidative phosphorylation in mitochondria. Oxygen is converted to energy, and, as a natural byproduct, reactive oxygen species are produced. Reactive oxygen species can act as mediators, and both these and the HBO2-mediated increase in oxygen supply have the potential to influence the cellular processes involved in sepsis. The pathophysiology of sepsis can be explained comprehensively through resistance and tolerance to infection. We argue that HBO2 treatment may protect the host from collateral tissue damage during resistance by reducing neutrophil extracellular traps, inhibiting neutrophil adhesion to vascular endothelium, reducing proinflammatory cytokines, and halting the Warburg effect, while also assisting the host in tolerance to infection by reducing iron-mediated injury and upregulating anti-inflammatory measures. Finally, we show how inflammation and oxygen-sensing pathways are connected on the cellular level in a self-reinforcing and detrimental manner in inflammatory conditions, and with support from a substantial body of studies from the literature, we conclude by demonstrating that HBO2 treatment can intervene to maintain homeostasis.

Hyperbaric oxygenation improve red blood cell deformability in patients with acute or chronic inflammation

INTRODUCTION

Red blood cells (RBC) are one of the key elements of the microcirculation. Their ability to pass through capillaries and to deliver oxygen to cells is due to their large degree of deformability linked to the characteristics of the RBC membrane. Alterations in RBC deformability as a result of membrane damage, linked in part to increased synthesis of reactive oxygen species (ROS), can be observed in several diseases, such as sepsis, and may contribute to the altered microcirculation observed in these pathologies. Hyperbaric oxygen therapy (HBOT), with inhalation of 100 % oxygen, has been proposed in several acute or chronic pathologies, including carbon monoxide poisoning.

OBJECTIVE

We investigated the effects of HBOT on oxidative stress from ROS produced by myeloperoxidase (MPO) and on RBC deformability in patients with acute or chronic inflammation (n = 10), in patients with acute carbon monoxide poisoning (n = 10), and in healthy volunteers (n = 10).

METHODS

RBC deformability was evaluated before and after HBOT in the various populations using the ektacytometry technique (Laser-assisted Optical Rotational Red Cell Analyzer - LORRCA). Deformability was determined by the elongation index (EI) in relation to the shear stress (SS) over a range of 0.3 to 50 Pa. Oxidative stress was estimated through changes in proteins (chlorotyrosine and homocitrulline) induced by MPO activity measured by liquid chromatography-tandem mass spectrometry analysis.

RESULTS

Before HBOT, EI was significantly lower in patients with acute or chronic inflammation than in healthy volunteers and patients with acute carbon monoxide poisoning for the majority of SS values studied. After one session of HBOT, the EI was significantly higher than before HBOT for SS values of 1.93 Pa or higher in patients with acute or chronic inflammation. This effect remains constant after 10 sessions. There were no differences before and after HBOT in protein or amino acid oxidation due to ROS generation mediated by MPO in the three populations.

CONCLUSIONS

Our results confirm altered RBC deformability in patients with acute and chronic conditions associated with an underlying inflammatory process. HBOT improves deformability only after one session and therefore may improve microcirculation in this population. According to our results, this improvement does not seem mediated by the ROS pathway via MPO. These results need to be confirmed in a larger population.

Hyperbaric Oxygen as Successful Monotherapy for a Severe Ulcerative Colitis Flare

This report presents a case of severe ulcerative colitis treated with hyperbaric oxygen as successful monotherapy.

Hyperbaric oxygen therapy in inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND

Translational data suggest a potential role of hyperbaric oxygen therapy (HBOT) in a subset of patients with inflammatory bowel disease (IBD). We performed a systematic review and meta-analysis for the efficacy and safety of HBOT in IBD.

METHODS

We searched Pubmed, Embase and CENTRAL to identify studies reporting the efficacy of HBOT in ulcerative colitis or Crohn's disease. We pooled the response rates for HBOT in ulcerative colitis and Crohn's disease separately.

RESULTS

A total 18 studies were included in the systematic review and 16 in the analysis. The overall response rate of HBOT in ulcerative colitis was 83.24% (95% confidence interval: 61.90-93.82), while the response in Crohn's disease was 81.89 (76.72-86.11). The results of randomized trials for HBOT as adjuvant therapy in ulcerative colitis were conflicting. The complete healing of fistula in fistulizing Crohn's disease was noted 47.64% (22.05-74.54), while partial healing was noted in 34.29% (17.33-56.50%). Most of the adverse events were minor.

CONCLUSION

Observational studies suggest benefit of use of HBOT in ulcerative colitis flares and Crohn's disease. However, adequately powered randomized trials are needed to draw a definite conclusion.

A Review of Hyperbaric Oxygen Therapy for Inflammatory Bowel Disease

IBD (inflammatory bowel disease) characterized by chronic inflammation of the gastrointestinal (GI) tract is one of the chronic diseases the prevalence of which has been increasing globally. In the past few decades, significant improvements were made in the treatments relating to IBD which have reduced the hospitalization and mortality rates; however, there is still room for improvement with other alternative therapies. HBOT (hyperbaric oxygen treatment) is one of the effective therapies used in treating various conditions including wounds, decompression sickness, stroke, etc. Several studies have reported the role of HBOT as an adjunctive treatment to IBD, while adopting conventional treatment procedures. There is an increasing trend of research in this particular area. Studies have shown that HBOT reflects its therapeutic effect by controlling inflammation, reducing oxidation stress, improving the process of cleaning damaged cells and recruiting the cells involved in repair; thereby improving the immunity response system. In this context, the purpose of this review is to summarize past clinical and experimental studies and to understand the role of hyperbaric treatment for IBD. The findings from the review have suggested that hyperbaric therapy can be an effective adjunctive approach for IBD, based on which some ideas for future clinical and research work are provided.

Adjunctive Hyperbaric Oxygen Therapy in Refractory Crohn's Disease: An Observational Study

Background and Aims

Patients may experience complications of Crohn's disease (CD) even when treated with optimal medical therapy strategies. Previous data have shown the efficacy of hyperbaric oxygen therapy (HBOT) in the management of complicated CD. However, there is no consensus regarding the optimal number of sessions or duration of treatment regimens. The aim of the present study was to investigate the efficacy of HBOT in CD patients who were refractory to conventional medical management.

Methods

This study included patients who underwent HBOT for the treatment of the following complications: perianal fistulizing Crohn's disease (pCD), enterocutaneous fistulas (ECF), or pyoderma gangrenosum (PG). Complete healing was defined as the closure of external orifice and the absence of active draining (in pCD), complete wound healing (in PG), and granulation or complete wound epithelialization with no enteric draining (in ECF). The persistence of draining and the absence of wound granulation were defined as incomplete healing.

Results

Forty patients were included. The mean CD duration was 10.6 ± 5.8 years. pCD comprised most of the included patients (25/62.5%), followed by ECF (n = 13/32.5%) and PG (n = 6/15%). In two patients (5%), a combination of ECF and PG was diagnosed, and in one patient (2.5%), all three complications were observed. A total of 32 patients (82.5%) had complete healing. Patients with PG had the highest healing rates (100%), followed by those with ECF (84.6%) and pCD (80%).

Conclusions

Adjunctive HBO was associated with significant healing rates for CD-associated complications such as pCD, ECF, and PG.

Anti-Inflammatory Activity of Oat Beta-Glucans in a Crohn's Disease Model: Time- and Molar Mass-Dependent Effects

BACKGROUND

The incidence of Crohn's disease (CD) is increasing worldwide, and it has currently become a serious public health issue in society. The treatment of CD continues throughout a patient's lifetime, and therefore, it is necessary to develop new, effective treatment methods, including dietotherapy. The present study aimed to determine the effects of consumption of oat beta-glucans with different molar mass on colon inflammation (colitis) in the early stages of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced CD in an animal model.

METHODS

Sprague-Dawley rats (control and TNBS-induced CD) were divided into three dietary groups and fed for 3 days (reflecting acute inflammation) or 7 days (reflecting remission) with a feed containing 1% low (βGl) or high (βGh) molar mass oat beta-glucan or a feed without this polysaccharide. The level of colon inflammatory markers and the expression of cytokines and their receptor genes were measured by ELISA and RT-PCR methods, respectively.

RESULTS

Acute inflammation or remission (3 or 7 days after TNBS administration, respectively) stages of experimentally induced CD were characterized by an increase in the level of inflammatory markers (IL-1, IL-6, IL-10, IL-12, TNF-α, CRP, MPO, COX, and PGE2) and the disruption of some cytokine signaling pathways as well as macro- and microscopic changes of colon tissue. The consumption of oat beta-glucans reduced the level of inflammatory markers and recovered the signaling pathways and histological changes, with stronger effects of βGl after 7 days of colitis.

CONCLUSIONS

Dietary oat beta-glucans can reduce colitis at the molecular and organ level and accelerate CD remission.

Effects of Dietary Oat Beta-Glucans on Colon Apoptosis and Autophagy through TLRs and Dectin-1 Signaling Pathways-Crohn's Disease Model Study

Background: Crohn’s disease (CD) is characterized by chronic inflammation of the gastrointestinal tract with alternating periods of exacerbation and remission. The aim of this study was to determine the time-dependent effects of dietary oat beta-glucans on colon apoptosis and autophagy in the CD rat model. Methods: A total of 150 Sprague–Dawley rats were divided into two main groups: healthy control (H) and a TNBS (2,4,6-trinitrobenzosulfonic acid)-induced colitis (C) group, both including subgroups fed with feed without beta-glucans (βG−) or feed supplemented with low- (βGl) or high-molar-mass oat beta-glucans (βGh) for 3, 7, or 21 days. The expression of autophagy (LC3B) and apoptosis (Caspase-3) markers, as well as Toll-like (TLRs) and Dectin-1 receptors, in the colon epithelial cells, was determined using immunohistochemistry and Western blot. Results: The results showed that in rats with colitis, after 3 days of induction of inflammation, the expression of Caspase-3 and LC3B in intestinal epithelial cells did not change, while that of TLR 4 and Dectin-1 decreased. Beta-glucan supplementation caused an increase in the expression of TLR 5 and Dectin-1 with no changes in the expression of Caspase-3 and LC3B. After 7 days, a high expression of Caspase-3 was observed in the colitis-induced animals without any changes in the expression of LC3B and TLRs, and simultaneously, a decrease in Dectin-1 expression was observed. The consumption of feed with βGl or βGh resulted in a decrease in Caspase-3 expression and an increase in TLR 5 expression in the CβGl group, with no change in the expression of LC3B and TLR 4. After 21 days, the expression of Caspase-3 and TLRs was not changed by colitis, while that of LC3B and Dectin-1 was decreased. Feed supplementation with βGh resulted in an increase in the expression of both Caspase-3 and LC3B, while the consumption of feed with βGh and βGl increased Dectin-1 expression. However, regardless of the type of nutritional intervention, the expression of TLRs did not change after 21 days. Conclusions: Dietary intake of βGl and βGh significantly reduced colitis by time-dependent modification of autophagy and apoptosis, with βGI exhibiting a stronger effect on apoptosis and βGh on autophagy. The mechanism of this action may be based on the activation of TLRs and Dectin-1 receptor and depends on the period of exacerbation or remission of CD.

Hyperbaric oxygen therapy decreases mortality due to Fournier's gangrene: a retrospective comparative study

There is no consensus about the role of adjunctive hyperbaric oxygen therapy (HBOT) in the management of Fournier’s gangrene. The aim of this study was to compare the evolution of patients with Fournier’s gangrene treated with all classical measures with and without adjuvant HBOT. A retrospective comparative study regarding the evolution of patients treated for Fournier’s gangrene was conducted in two periods. In period I, from 1990 to 2002, patients received standard treatments for Fournier’s gangrene, which consisted of surgical debridement, antibiotic therapy and intensive care. In period II, from 2012 to 2019, adjunctive HBOT was added to the classical management strategy. All patients were assigned into four groups according to the anatomical severity classification and the area affected after the first debridement. This classification ensured that the groups could be comparable. The total number of patients in this study was 197, and these patients were divided into control group (118/59.9%) and HBOT group (79/40.1%). The mean age, comorbidities, and anatomical severity classification were similar between the two groups. In period I, 34 out of 118 (28.8%) patients died, while in the HBOT group, 3 out of 77 (3.7%) patients died (P < 0.001). The use of adjuvant HBOT in combination with classical treatment was associated with reduced mortality. This study was approved by the Institutional Review Board and the Ethics Committee of Ribeirão Preto Medical School, University of São Paulo, Brazil (No. 08/2018) on May 2, 2018.

Ulcerative colitis: Gut microbiota, immunopathogenesis and application of natural products in animal models

Ulcerative colitis (UC) is an inflammatory bowel disease with increasing incidence in the world, especially in developing countries. Although knowledge of its pathogenesis has progressed over the last years, some details require clarification. Studies have highlighted the role of microbial dysbiosis and immune dysfunction as essential factors that may initiate the typical high-grade inflammatory outcome. In order to better understand the immunopathophysiological aspects of UC, experimental murine models are valuable tools. Some of the most commonly used chemicals to induce colitis are trinitrobenzene sulfonic acid, oxazolone and dextran sodium sulfate. These may also be used to investigate new ways of preventing or treating UC and therefore improving targeting in human studies. The use of functional foods or bioactive compounds from plants may constitute an innovative direction towards the future of alternative medicine. Considering the above, this review focused on updated information regarding the 1. gut microbiota and immunopathogenesis of UC; 2. the most utilized animal models of the disease and their relevance; and 3. experimental application of natural products, not yet tested in clinical trials.

Beneficial Effects of Oat Beta-Glucan Dietary Supplementation in Colitis Depend on its Molecular Weight

Background: Inflammatory bowel diseases are an important health problem. Therefore, the aim of the present study was to compare the impact of isolated oat beta-glucan fractions of low and high molecular weight, taken as dietary supplementation, on inflammatory markers in the colitis model. Methods: Two groups of Sprague–Dawley rats—control and with experimentally induced colitis—were subsequently divided into three subgroups and fed over 21 days feed supplemented with 1% of low (βGl) or high (βGh) molecular weight oat beta-glucan fraction or feed without supplementation. The level of colon inflammatory markers, cytokines, and their receptors’ genes expressions and immune cells numbers were measured by ELISA, RT-PCR, and by flow cytometry methods, respectively. Results: The results showed moderate inflammation affecting the colon mucosa and submucosa, with significant changes in the number of lymphocytes in the colon tissue, elevated cytokines and eicosanoid levels, as well as disruption of the main cytokine and chemokine cell signaling pathways in colitis rats. Beta-glucans supplementation caused a reverse in the percentage of lymphocytes with stronger effects of βGh and reduction of the levels of the inflammatory markers, and improvement of cytokine and chemokine signaling pathways with stronger effects of βGl supplementation. Conclusions: The results indicate the therapeutic effect of dietary oat beta-glucan supplementation in the colitis in evident relation to the molecular weight of polymer.

Adjunctive Hyperbaric Oxygen Therapy promotes successful healing in patients with refractory Crohn's disease

PURPOSE

To investigate de adjunctive effect of Hyperbaric Oxygen Therapy in a group of patients with refractory Crohn's disease.

METHODS

A total of 29 subjects with refractory Crohn's disease were submitted to daily sessions of Hyperbaric Oxygen Therapy, in a 2800 Sechrist Monoplace Hyperbaric Chamber (Sechrist, USA) pressurized to 2.4 ATA. Each session lasted 2 hours. The endpoint was closure of enterocutaneous fistulas and complete healing of Pyoderma Gangrenosum and perineal Crohn's disease.

RESULTS

A total of 829 HBOT sessions were performed and no complications were noted. Overall success rate was 76% (22 cases). Pyoderma Gangrenosum and enterocutaneous fistulas had the highest successful healing rates (100% and 91%, respectively). Perineal Crohn's disease healing rate was 65%.

CONCLUSION

Adjunctive Hyperbaric Oxygen Therapy promoted satisfactory healing in a group of patients with refractory Crohn's disease.

Molecular hydrogen: a therapeutic antioxidant and beyond

Molecular hydrogen (H₂) medicine research has flourished since a landmark publication in Nature Medicine that revealed the antioxidant and cytoprotective effects of hydrogen gas in a focal stroke model. Emerging evidence has consistently demonstrated that molecular hydrogen is a promising therapeutic option for a variety of diseases and the underlying comprehensive mechanisms is beyond pure hydroxyl radicals scavenging. The non-toxicity at high concentrations and rapid cellular diffusion features of molecular hydrogen ensure the feasibility and readiness of its clinical translation to human patients.

Neuroprotective effect of hyperbaric oxygen therapy in a juvenile rat model of repetitive mild traumatic brain injury

Repetitive mild traumatic brain injury (rmTBI) is an important medical concern for adolescent athletes that can lead to long-term disabilities. Multiple mild injuries may exacerbate tissue damage resulting in cumulative brain injury and poor functional recovery. In the present study, we investigated the increased brain vulnerability to rmTBI and the effect of hyperbaric oxygen treatment using a juvenile rat model of rmTBI. Two episodes of mild cortical controlled impact (3 days apart) were induced in juvenile rats. Hyperbaric oxygen (HBO) was applied 1 hour/day × 3 days at 2 atmosphere absolute consecutively, starting at 1 day after initial mild traumatic brain injury (mTBI). Neuropathology was assessed by multi-modal magnetic resonance imaging (MRI) and tissue immunohistochemistry. After repetitive mTBI, there were increases in T2-weighted imaging-defined cortical lesions and susceptibility weighted imaging-defined cortical microhemorrhages, correlated with brain tissue gliosis at the site of impact. HBO treatment significantly decreased the MRI-identified abnormalities and tissue histopathology. Our findings suggest that HBO treatment improves the cumulative tissue damage in juvenile brain following rmTBI. Such therapy regimens could be considered in adolescent athletes at the risk of repeated concussions exposures.

The Response of Macrophages and Neutrophils to Hypoxia in the Context of Cancer and Other Inflammatory Diseases

Lack of oxygen (hypoxia) is a hallmark of a multitude of acute and chronic diseases and can be either beneficial or detrimental for organ restitution and recovery. In the context of inflammation, hypoxia is particularly important and can significantly influence the course of inflammatory diseases. Macrophages and neutrophils, the chief cellular components of innate immunity, display distinct properties when exposed to hypoxic conditions. Virtually every aspect of macrophage and neutrophil function is affected by hypoxia, amongst others, morphology, migration, chemotaxis, adherence to endothelial cells, bacterial killing, differentiation/polarization, and protumorigenic activity. Prominent arenas of macrophage and neutrophil function, for example, acute/chronic inflammation and the microenvironment of solid tumors, are characterized by low oxygen levels, demonstrating the paramount importance of the hypoxic response for proper function of these cells. Members of the hypoxia-inducible transcription factor (HIF) family emerged as pivotal molecular regulators of macrophages and neutrophils. In this review, we will summarize the molecular responses of macrophages and neutrophils to hypoxia in the context of cancer and other chronic inflammatory diseases and discuss the potential avenues for therapeutic intervention that arise from this knowledge.

Advances in treatment of inflammatory bowel disease

Because of varied clinical manifestations, long duration and recurrence, and lack of diagnostic criteria, the treatment of inflammatory bowel disease (IBD) is very complicated. The treatment should be aimed at its diverse pathogenesis and be multimodal, including controlling active inflammation, regulating immune function, use of biological agents, and stem cell transplantation. Some cases even require surgical treatment.