Treatment of diverticular disease: an update on latest evidence and clinical implications

Safety and efficacy of faecal microbiota transplantation in patients with acute uncomplicated diverticulitis: study protocol for a randomised placebo-controlled trial

Background

Little is known about the involvement of gut microbiota in the disease course of diverticulitis and the potential benefits of manipulating the gut milieu. We propose to conduct a randomised placebo-controlled feasibility trial of faecal microbiota transplantation (FMT) given as capsules to patients with acute uncomplicated diverticulitis.

Objectives

The objective is primarily to investigate the feasibility of clinical safety, explore efficacy associated with FMT in this patient population, and examine changes in patient-reported quality of life and the composition and function of the gut microbiota.

Design

Study protocol for a randomised placebo-controlled trial.

Methods and analysis

Participants with acute, uncomplicated diverticulitis, as confirmed by computed tomography (CT) scan, will be recruited from Odense University Hospital (Denmark) and randomly assigned to either the intervention group or the control group. The intervention group will consist of 20 patients who receive encapsulated FMT. The control group will also consist of 20 patients, receiving placebo capsules. Primary safety endpoint: Patient safety is monitored by (a) the number of re-admissions and (b) the number of adverse events within 3 months of FMT/placebo; Primary efficacy endpoint: Reduction in the proportion of patients treated with antibiotics within 3 months following FMT/placebo; Secondary outcome: Change from baseline to 3 months in the GI-QLI questionnaire. Results will be analysed using an intention-to-treat approach. Adverse events or unintended consequences will be reported.

Ethics and discussion

This is the first study to investigate the safety and efficacy of FMT in patients with acute uncomplicated diverticulitis. The project has the potential to broaden the knowledge and literature on the role of the intestinal microbiota in diverticulitis, and we believe it will elevate our understanding of cause and effect.

Trial registration

Informed consent is obtained from all participants. The study is approved by the regional ethics committee (ref. S-20230023) and the Danish Data Protection Agency (ref. 24/2435). The trial was registered on clinicaltrials.gov (NCT06254625) on 10th February 2024.

The Unexplored Role of Mitochondria-Related Oxidative Stress in Diverticular Disease

The pathophysiology of diverticular disease (DD) is not well outlined. Recent studies performed on the DD human ex vivo model have shown the presence of a predominant transmural oxidative imbalance whose origin remains unknown. Considering the central role of mitochondria in oxidative stress, the present study evaluates their involvement in the alterations of DD clinical phenotypes. Colonic surgical samples of patients with asymptomatic diverticulosis, complicated DD, and controls were analyzed. Electron microscopy, protein expression, and cytofluorimetric analyses were performed to assess the contribution of mitochondrial oxidative stress. Functional muscle activity was tested on cells in response to contractile and relaxant agents. To assess the possibility of reverting oxidative damages, N-acetylcysteine was tested on an in vitro model. Compared with the controls, DD tissues showed a marketed increase in mitochondrial number and fusion accompanied by the altered mitochondrial electron transport chain complexes. In SMCs, the mitochondrial mass increase was accompanied by altered mitochondrial metabolic activity supported by a membrane potential decrease. Ulteriorly, a decrease in antioxidant content and altered contraction-relaxation dynamics reverted by N-acetylcysteine were observed. Therefore, the oxidative stress-driven alterations resulted in mitochondrial impairment. The beneficial effects of antioxidant treatments open new possibilities for tailored therapeutic strategies that have not been tested for this disease.

[Non-distinctive abdominal pain: is it diverticular disease or not?]

Acute abdominal pain may relate to specific organ systems and needs an interdisciplinary approach with close collaboration between internal and surgical disciplines. Main objective is to shorten the diagnostic work-up between the beginning of the symptoms and their therapy. After clarifying of the five w-questions: when, how, how long, why, and where, abdominal ultrasound, ECG, laboratory diagnostics and early application of computed tomography should be performed.For the most part, chronic abdominal pain is caused by disorders of the gut-brain-axis such as the irritable bowel syndrome. Because of the synaptic plasticity, the processing of pain is dynamic and cannot be related to a single organ system. This problem is obvious in patients with irritable bowel syndrome and colonic diverticula, which may be interpreted as symptomatic uncomplicated diverticular disease (SUDD, type 3a). However, a reliable clinical differentiation between both groups is not possible. The establishment of SUDD (type 3a) considerable widened the application area of mesalazine.

Emergency medicine updates: Acute diverticulitis

INTRODUCTION

Acute diverticulitis is a condition commonly seen in the emergency department (ED). Therefore, it is important for emergency medicine clinicians to be aware of the current evidence regarding the diagnosis and management of this disease.

OBJECTIVE

This paper evaluates key evidence-based updates concerning acute diverticulitis for the emergency clinician.

DISCUSSION

Diverticulitis is a complication of diverticulosis and most commonly affects the sigmoid and descending colon in Western countries. History and examination can suggest the diagnosis, with abdominal pain and tenderness in the left lower quadrant being the most common symptom and sign, respectively. Change in bowel habits and fever may also occur. Laboratory testing may demonstrate leukocytosis or an elevated C-reactive protein. Imaging options can include computed tomography (CT) of the abdomen and pelvis with intravenous contrast, magnetic resonance imaging (MRI), or ultrasound (US), though most classification systems for diverticulitis incorporate CT findings. While the majority of diverticulitis cases are uncomplicated, complications may affect up to 25% of patients. Treatment of complicated diverticulitis requires antibiotics and surgical consultation. Antibiotics are not required in select patients with uncomplicated diverticulitis. Appropriate patients for supportive care without antibiotics should be well-appearing, have pain adequately controlled, be able to tolerate oral intake, be able to follow up, have no complications, and have no immunocompromise or severe comorbidities.

CONCLUSIONS

An understanding of literature updates can improve the ED care of patients with acute diverticulitis.

One-year cyclic therapy with rifaximin-α is effective in the treatment of SUDD (Symptomatic Uncomplicated Diverticular Disease) also in patients with a history of complicated diverticulitis

<b><br>Introduction:</b> The treatment of diverticulosis symptoms in patients with a history of diverticulitis is a challenge in everyday clinical practice.</br> <b><br>Aim:</b> Efficacy assessment of a cyclic, year-long treatment with rifaximin-α in patients with symptomatic uncomplicated diverticular disease (SUDD) and a history of past diverticulitis.</br> <b><br>Material and methods:</b> This study is a multicenter, retrospective, observational study involving 48 centers. The study group included patients who reported to the outpatient clinic within a month with SUDD symptoms, who had a history of diverticulitis, and who were given a cyclic rifaximin-α treatment of 2 x 400 mg/day for 7 days and then once a month for 12 months. Epidemiological and demographic data, the course of diverticulosis, the number of inflammation episodes and their diagnoses, complications, symptoms of SUDD, and its treatment were evaluated. The efficacy of rifaximin-α therapy was assessed on a 4-point scale (0 – no symptoms, 3 – severe symptoms) every 3 months, and analyzed: pain, tenderness, bloating, bowel movements, and recurrence of inflammation during the 12-month treatment.</br> <b><br>Results:</b> 178 patients (67% women, median age 65 years [34–92]) were included in the study. The average duration of diverticulosis was 6.4 years (3–20), and 59% of patients had more than one episode of diverticulitis during this period. In total, 87% of patients had symptoms of SUDD after or between episodes of diverticulitis. Abdominal pain was the most common symptom (92%). An inflammation episode was diagnosed using imaging in 50.5% of cases, and the rest – based on typical clinical symptoms. As many as 46.2% of patients required hospitalization, and complications were diagnosed in 44% of cases. One hundred and seventy (95%) patients completed the 12-month rifaximin-α therapy. Changes in the severity of pain, abdominal tenderness, diarrhea, constipation, and bloating were assessed every 3 months. After 12 months of treatment with rifaximin-α, there was a statistically significant reduction in the severity of symptoms overall (median from 1.5 [0–3 points] to 0.2; P<0.001) and each symptom evaluated individually. Regardless of the previous diagnostic method of diverticulitis (imaging or typical clinical presentation) or its complications (e.g. perforation, abscess), treatment with rifaximin-α was equally effective.</br> <b><br>Conclusions:</b> Cyclic therapy with rifaximin-α is effective in treating SUDD symptoms and in preventing the recurrence of symptoms, also in patients with a history of diverticulitis – regardless of how the diagnosis was made and disease complications. The extended treatment regimen leads to a gradual resolution of symptoms during 12 months of observation. Cyclic use of rifaximin-α is necessary to maintain symptom remission.</br>

Does the microbiome play a role in the pathogenesis of colonic diverticular disease? A systematic review

BACKGROUND AND AIMS

The role of the microbiota in diverticulosis and diverticular disease is underexplored. This systematic review aimed to assess all literature pertaining to the microbiota and metabolome associations in asymptomatic diverticulosis, symptomatic uncomplicated diverticular disease (SUDD), and diverticulitis pathophysiology.

METHODS

Seven databases were searched for relevant studies published up to September 28, 2022. Data were screened in Covidence and extracted to Excel. Critical appraisal was undertaken using the Newcastle Ottawa Scale for case/control studies.

RESULTS

Of the 413 papers screened by title and abstract, 48 full-text papers were reviewed in detail with 12 studies meeting the inclusion criteria. Overall, alpha and beta diversity were unchanged in diverticulosis; however, significant changes in alpha diversity were evident in diverticulitis. A similar Bacteroidetes to Firmicutes ratio compared with controls was reported across studies. The genus-level comparisons showed no relationship with diverticular disease. Butyrate-producing microbial species were decreased in abundance, suggesting a possible contribution to the pathogenesis of diverticular disease. Comamonas species was significantly increased in asymptomatic diverticulosis patients who later developed diverticulitis. Metabolome analysis reported significant differences in diverticulosis and SUDD, with upregulated uracil being the most consistent outcome in both. No significant differences were reported in the mycobiome.

CONCLUSION

Overall, there is no convincing evidence of microbial dysbiosis in colonic diverticula to suggest that the microbiota contributes to the pathogenesis of asymptomatic diverticulosis, SUDD, or diverticular disease. Future research investigating microbiota involvement in colonic diverticula should consider an investigation of mucosa-associated microbial changes within the colonic diverticulum itself.

Symptomatic Uncomplicated Diverticular Disease (SUDD): Practical Guidance and Challenges for Clinical Management

Symptomatic Uncomplicated Diverticular Disease (SUDD) is a syndrome within the diverticular disease spectrum, characterized by local abdominal pain with bowel movement changes but without systemic inflammation. This narrative review reports current knowledge, delivers practical guidance, and reveals challenges for the clinical management of SUDD. A broad and common consensus on the definition of SUDD is still needed. However, it is mainly considered a chronic condition that impairs quality of life (QoL) and is characterized by persistent left lower quadrant abdominal pain with bowel movement changes (eg, diarrhea) and low-grade inflammation (eg, elevated calprotectin) but without systemic inflammation. Age, genetic predisposition, obesity, physical inactivity, low-fiber diet, and smoking are considered risk factors. The pathogenesis of SUDD is not entirely clarified. It seems to result from an interaction between fecal microbiota alterations, neuro-immune enteric interactions, and muscular system dysfunction associated with a low-grade and local inflammatory state. At diagnosis, it is essential to assess baseline clinical and Quality of Life (QoL) scores to evaluate treatment efficacy and, ideally, to enroll patients in cohort studies, clinical trials, or registries. SUDD treatments aim to improve symptoms and QoL, prevent recurrence, and avoid disease progression and complications. An overall healthy lifestyle - physical activity and a high-fiber diet, with a focus on whole grains, fruits, and vegetables - is encouraged. Probiotics could effectively reduce symptoms in patients with SUDD, but their utility is missing adequate evidence. Using Rifaximin plus fiber and Mesalazine offers potential in controlling symptoms in patients with SUDD and might prevent acute diverticulitis. Surgery could be considered in patients with medical treatment failure and persistently impaired QoL. Still, studies with well-defined diagnostic criteria for SUDD that evaluate the safety, QoL, effectiveness, and cost-effectiveness of these interventions using standard scores and comparable outcomes are needed.

German guideline diverticular disease/diverticulitis: Part II: Conservative, interventional and surgical management

Diverticulosis and diverticular disease are ranked among the most common gastroenterological diseases and conditions. While for many years diverticulitis was found to be mainly an event occurring in the elder population, more recent work in epidemiology demonstrates increasing frequency in younger subjects. In addition, there is a noticeable trend towards more complicated disease. This may explain the significant increase in hospitalisations observed in recent years. It is not a surprise that the number of scientific studies addressing the clinical and socioeconomic consequences in the field is increasing. As a result, diagnosis and conservative as well as surgical management have changed in recent years. Diverticulosis, diverticular disease and diverticulitis are a complex entity and apparently an interdisciplinary challenge. To meet theses considerations the German Societies for Gastroenterology and Visceral Surgery decided to create joint guidelines addressing all aspects in a truely interdisciplinary fashion. The aim of the guideline is to summarise and to evaluate the current state of knowledge on diverticulosis and diverticular disease and to develop statements as well as recommendations to all physicians involved in the management of patients with diverticular disease.

Diverticular disease: a clinical review

Diverticular disease is an umbrella term encompassing symptomatic diverticulosis, uncomplicated and complicated diverticulitis. The presence of diverticula increases with age, affecting up to 70% of the population by 80 years of age. It is associated with a significant economic burden in terms of healthcare costs, hospitalisation, and resource use. Although mortality from non-complicated diverticulosis is extremely rare, morbidity and mortality risk increase ten-fold with complications such as perforation or fistula. This article will examine diverticular disease, its pathogenesis, symptoms and complications. Additionally, the surgical and non-surgical treatment options will be discussed, including the role of antibiotics.

Diverticulosis, Diverticulitis, and Diverticular Bleeding

Diverticulosis is an anatomic change in the colon that is characterized by outpouching of the mucosa and submucosa through the muscularis. Its prevalence increases with age so most of the elderly patients have this condition. Although diverticulosis is common, diverticular disease, in which there are clinical sequelae, is rare. This collective term includes diverticulitis, diverticular hemorrhage and less well-defined entities such as segmental colitis associated with diverticulosis, and symptomatic uncomplicated diverticular disease. Diverticulitis presents as acute lower abdominal pain, and initial management traditionally includes antibiotics, with surgery reserved for complicated disease, although newer evidence questions the optimal role and timing of both interventions.

Symptomatic uncomplicated diverticular disease management: an innovative food-grade formulation of Curcuma longa and Boswellia serrata extracts

Background

The treatment of symptomatic uncomplicated colonic diverticular disease (SUDD) is still under debate, and new data show a pathogenic role of dysbiosis and low-grade inflammation in intestinal mucosa. Recent research has highlighted the anti-inflammatory effects of botanical extracts such as Curcuma longa L. and Boswellia serrata Roxb. ex Colebr. The aim of this work is to investigate the potential role of a new delivery formulation of the association of curcumin and boswellia phytosome extracts (CBP) in SUDD.

Methods

In a 30-day one-group longitudinal explanatory study, patients (men and women) were treated with an innovative association of CBP standardized extracts, 500 mg bid.

Results

Treatment of SUDD with the association of CBP was followed by a significant decrease in abdominal pain (p<0.0001). The study group showed that CBP supplementation was efficacious within 10 days and that efficacy was maintained almost constant until the 30th day of intervention.

Conclusion

A phytosome of curcumin and boswellia extracts may be useful for the relief of SUDD pain. However, controlled studies should be performed for final conclusions to be drawn.

Computational analysis of mechanical stress in colonic diverticulosis

Diverticulosis results from the development of pouch-like structures, called diverticula, over the colon. The etiology of the disease is poorly understood resulting in a lack of effective treatment approaches. It is well known that mechanical stress plays a major role in tissue remodeling, yet its role in diverticulosis has not been studied. Here, we used computational mechanics to investigate changes in stress distribution engendered over the colon tissue by the presence of a pouch-like structure. The objectives of the study were twofold: (1) observe how stress distribution changes around a single pouch and (2) evaluate how stress elevation correlates with the size of the pouch. Results showed that high stresses are concentrated around the neck of a pouch, and their values and propagation increase with the size of the pouch neck rather than the pouch surface area. These findings suggest that stress distribution may change in diverticulosis and a vicious cycle may occur where pouch size increases due to stress elevation, which in turn elevates stress further and so on. Significant luminal pressure reduction would be necessary to maintain stress at normal level according to our results and therapeutic approaches aimed directly at reducing stress should rather be sought after.

Role of dietary fibre in older adults with asymptomatic (AS) or symptomatic uncomplicated diverticular disease (SUDD): Systematic review and meta-analysis

Dietary fibre and probiotics may play a role in the management of diverticular disease. This systematic review synthesises the evidence on the effects of dietary fibre modifications, with or without the use of probiotics, on the incidence in older adults of asymptomatic (AS) or symptomatic uncomplicated diverticular disease (SUDD), as well as on gastrointestinal function and symptoms. Five electronic databases were searched for studies through to December 2018. The body of evidence was appraised using the Cochrane Risk of Bias tool and GRADE. Nine studies were included, with mean sample ages ranging from 57 to 70 years, and three meta-analyses were performed. Only one study, with high risk of bias, measured the effect of dietary fibre on the incidence of diverticulitis. Dietary fibre supplementation improved stool weight (MD: 42 g/day, P < 0.00001; GRADE level of evidence: low), but had no significant effect on gastrointestinal symptoms (SMD: -0.13, P = 0.16; GRADE level of evidence: low) or stool transit time (MD: -3.70, P = 0.32 GRADE level of evidence: low). There was "very low" confidence for the body of evidence supporting symbiotics for AS or SUDD. A high dietary fibre intake, in line with dietary guidelines, may improve gastrointestinal function and is recommended in patients with AS or SUDD. Dietary fibre supplementation should be considered on an individualised basis to improve bowel function, while any recommendation on symbiotic supplements requires further well-designed research. Future studies should also measure the impact on the incidence of diverticulitis.

The management of diverticulitis: a review of the guidelines

Radiological evidence of inflammation, using computed tomography (CT), is needed to diagnose the first occurrence of diverticulitis. CT is also warranted when the severity of symptoms suggests that perforation or abscesses have occurred. Diverticulitis is classified as complicated or uncomplicated based on CT scan, severity of symptoms and patient history; this classification is used to direct management. Outpatient treatment is recommended in afebrile, clinically stable patients with uncomplicated diverticulitis. For patients with uncomplicated diverticulitis, antibiotics have no proven benefit in reducing the duration of the disease or preventing recurrence, and should only be used selectively. For complicated diverticulitis, non-operative management, including bowel rest and intravenous antibiotics, is indicated for small abscesses; larger abscesses of 3-5 cm should be drained percutaneously. Patients with peritonitis and sepsis should receive fluid resuscitation, rapid antibiotic administration and urgent surgery. Surgical intervention with either Hartmann procedure or primary anastomosis, with or without diverting loop ileostomy, is indicated for peritonitis or in failure of non-operative management. Colonoscopy is recommended for all patients with complicated diverticulitis 6 weeks after CT diagnosis of inflammation, and for patients with uncomplicated diverticulitis who have suspicious features on CT scan or who otherwise meet national bowel cancer screening criteria.

Italian nationwide survey of pharmacologic treatments in diverticular disease: Results from the REMAD registry

BACKGROUND

Although diverticular disease is a common condition, its effective treatment is challenging in clinical practice.

OBJECTIVE

The objective of this article is to assess pharmacological management in different clinical settings of diverticular disease and factors associated with treatment using the Italian registry Registro Malattia Diverticolare (REMAD).

METHODS

At study enrolment, patients were categorised into subgroups: diverticulosis, symptomatic uncomplicated diverticular disease and previous diverticulitis. We registered demographic, clinical and lifestyle factors, quality of life and the use of treatments for diverticular disease in the last year. Logistic regression analysis assessed the association between clinical factors and treatment consumption.

RESULTS

A total of 500 of the 1206 individuals included had had at least one treatment for diverticular disease in the last year: 23.6% (166/702) of patients with diverticulosis, 55.9% (165/295) of patients with symptomatic diverticular disease, and 80.9% (169/209) of patients with previous diverticulitis (p < 0.001). In multivariate analysis, the following factors were significantly associated with treatment use: female gender, family history of colonic diverticula, organic digestive comorbidity and impaired physical quality of life components.

CONCLUSION

Individuals with diverticular disease take medications based on the different clinical settings of disease. We identified different features associated with treatment use in the distinct clinical entities of diverticular disease.ClinicalTrial.gov Identifier: NCT03325829.

IBS-like manifestations in large intestine diverticular disease

The article is devoted to the diverticular colon disease, its uncomplicated form, the connection with age. Symptoms allowing to define presence at this form of disease of IBS-like symptoms – pains and infringements of the psycho-emotional status are highlighted. The results of psychometric research and psychiatrist’s consultation of 102 patients are presented. The role of obesity in the genesis of diverticular disease is highlighted. The significance of spasmolytic therapy, in particular mebeverine, is presented.

Cyclic rifaximin therapy effectively prevents the recurrence of symptoms after exacerbation of symptomatic uncomplicated diverticular disease: a retrospective study

INTRODUCTION

Symptomatic uncomplicated diverticular disease (SUDD) is the most common manifestation of diverticulosis. Data concerning the optimal treatment after SUDD exacerbation are inconsistent.

AIM

To assess the effectiveness and necessity of cyclic rifaximin treatment for recurrent SUDD symptoms and for preventing exacerbations in patients who responded to the initial treatment.

MATERIAL AND METHODS

A retrospective observational study was performed in 2017. Physicians responded to a survey on patients with recurrent SUDD during the observation period, who were cyclically treated with rifaximin 400 mg b.i.d. for 7 days per month. The patients' SUDD history, diagnostic methods, treatment, and results were evaluated.

RESULTS

In total 294 patients were included in this study (67% women, median age: 65 years (26-87)). The mean duration of diverticular disease (DD) was 4.5 years (1-20), and 88% had at least one repeated episode of SUDD exacerbation before rifaximin. A total of 267 patients were treated with rifaximin. Changes in the severity of pain, abdominal tenderness, diarrhoea, constipation, and bloating were assessed every 2 months. After 6 months of rifaximin treatment there was a statistically significant reduction in the total severity score (median from 1.8 (max. 3 points) to 0.2; p < 0.0001; sum from 9.37 (max. 18 points) to 1.35; p < 0.0001) and an improvement in individual symptom score.

CONCLUSIONS

Cyclical rifaximin is effective in treating exacerbation of SUDD. This regimen leads to a gradual cessation of symptoms over a 6-month period. In patients who responded to the initial treatment, cyclic rifaximin therapy is needed to maintain remission.

Treatment of diverticular disease, targeting symptoms or underlying mechanisms

Diverticular disease (DD) is a highly prevalent disease in western industrialized countries that encompasses a complex set of disorders. Because of its complexity and heterogeneity, both from a pathogenic and a clinical point of view, the management of this disease represent a challenge in clinical practice. This review aims to analyze and summarize the most recent evidence on the medical strategies for DD, considering separately the different stages of the disease, from prevention of diverticula formation to treatment of acute diverticulitis and prevention of recurrences. Based on some evidence, dietary fiber is useful to prevent diverticula formation and in diverticulosis, with no pharmacological treatment in these settings. Treatment of symptomatic uncomplicated diverticular disease as well as primary prevention of acute diverticulitis is based on probiotics, fibres, mesalazine and rifaximin, individually or as combination therapy, although a standard approach has not yet been defined. On the contrary, in acute diverticulitis (AD) recent acquisitions have clarified and standardized the role of systemic antibiotics, reserving its use only to complicated forms and in selected cases of uncomplicated disease. Secondary prevention of AD is essentially based on mesalazine and rifaximin but, despite promising results, no strong evidence have been produced. To date, grey areas remain in the medical management of DD.

Whole Fruits and Fruit Fiber Emerging Health Effects

Less than 10% of most Western populations consume adequate levels of whole fruits and dietary fiber with typical intake being about half of the recommended levels. Evidence of the beneficial health effects of consuming adequate levels of whole fruits has been steadily growing, especially regarding their bioactive fiber prebiotic effects and role in improved weight control, wellness and healthy aging. The primary aim of this narrative review article is to examine the increasing number of health benefits which are associated with the adequate intake of whole fruits, especially fruit fiber, throughout the human lifecycle. These potential health benefits include: protecting colonic gastrointestinal health (e.g., constipation, irritable bowel syndrome, inflammatory bowel diseases, and diverticular disease); promoting long-term weight management; reducing risk of cardiovascular disease, type 2 diabetes and metabolic syndrome; defending against colorectal and lung cancers; improving odds of successful aging; reducing the severity of asthma and chronic obstructive pulmonary disease; enhancing psychological well-being and lowering the risk of depression; contributing to higher bone mineral density in children and adults; reducing risk of seborrheic dermatitis; and helping to attenuate autism spectrum disorder severity. Low whole fruit intake represents a potentially more serious global population health threat than previously recognized, especially in light of the emerging research on whole fruit and fruit fiber health benefits.

Pathophysiology of diverticular disease

Inflammation of diverticula, or outpouchings of the colonic mucosa and submucosa through the muscularis layer, leads to diverticulitis. The development of diverticular disease, encompassing both diverticulosis and diverticulitis, is a result of genetic predisposition, lifestyle, and environmental factors, including the microbiome. Areas covered: Previous reports implicated genetic predisposition, environmental factors, and colonic dysmotility in diverticular disease. Recent studies have associated specific host immune responses and the microbiome as contributors to diverticulitis. To review pertinent literature describing pathophysiological factors associated with diverticulosis or diverticulitis, we searched the PubMed database (March 2018) for articles considering the role of colonic architecture, genetic predisposition, environment, colonic motility, immune response, and the microbiome. Expert commentary: In the recent years, research into the molecular underpinnings of diverticular disease has enhanced our understanding of diverticular disease pathogenesis. Although acute uncomplicated diverticulitis is treated with broad spectrum antibiotics, evaluation of the microbiome has been limited and requires further comprehensive studies. Evidence suggests that a deregulation of the host immune response is associated with both diverticulosis and diverticulitis. Further examining these pathways may reveal proteins that can be therapeutic targets or aid in identifying biological determinants of clinical or surgical decision making.

Recent advances in understanding and managing diverticulitis

In the past few decades, the increasing socioeconomic burden of acute diverticulitis (AD) has become evident, and with the growth of the population age, this significant economic impact will likely continue to rise. Furthermore, recent evidence showed an increased rate of hospital admissions especially evident among women and younger individuals. The natural history and pathophysiology of this clinical condition is still to be fully defined, and efforts continue to be made in the identification of risk factors and the establishment of relative preventive strategies. The actual therapeutic strategies aimed to modulate gut microbiota, such as rifaximin or probiotics, or to reduce mucosal inflammation, such as mesalazine, present a relatively poor efficacy for both the prevention of the first AD episode (primary prevention) and its recurrence (secondary prevention). In the last few years, the main goal achieved has been in the management of AD in that uncomplicated AD can, to a larger extent, be managed in an outpatient setting with no or little supportive therapy, a strategy that will certainly impact on the health costs of this disease. The problem of AD recurrence remains a topic of debate. The aim of this review is to present updated evidence on AD epidemiology and relative open clinical questions and to analyze in detail predisposing and protective factors with an attempt to integrate their possible modes of action into the several pathogenic mechanisms that have been suggested to contribute to this multifactorial disease. A unifying hypothesis dealing with the colonic luminal and extra-luminal microenvironments separately is provided. Finally, evidence-based changes in therapeutic management will be summarized. Because of an ascertained multifactorial pathogenesis of uncomplicated and complicated AD, it is probable that a single 'causa prima' will not be identifiable, and a better stratification of patients could allow one to pursue tailored therapeutic algorithm strategies.