Long-term efficacy of rifaximin to manage the symptomatic uncomplicated diverticular disease of the colon

Rifaximin and alternative agents in the management of irritable bowel syndrome: A comprehensive review

Rifaximin, a broad-spectrum antibiotic, boasts a unique chemical composition and pharmacokinetic profile, rendering it highly effective in treating irritable bowel syndrome (IBS). Its minimal systemic absorption confines its impact to the gastrointestinal (GI) tract, where it yields significant therapeutic benefits. This review examines rifaximin's physico-chemical attributes and its role in managing IBS symptoms. Its molecular structure facilitates intestinal lumen retention postoral administration, minimizing systemic exposure and adverse effects. This targeted action is crucial in addressing the gut microbiota's role in IBS pathophysiology. By modifying microbial populations and their metabolite production, rifaximin mitigates symptoms like bloating, irregular bowel habits, and abdominal pain associated with IBS. It achieves this by reducing pathogenic bacteria and altering bacterial metabolism, enhancing mucosal and immune function. Clinical trials affirm rifaximin's superiority over placebo and conventional therapies in alleviating overall IBS symptoms and addressing small intestine bacterial overgrowth (SIBO). Despite its promising efficacy and sustained symptom relief, further research is essential to optimize long-term effectiveness and dosing regimens. Rifaximin stands as a vital treatment option for IBS due to its distinctive properties and clinical utility; yet, ongoing investigation is imperative for maximizing its therapeutic benefits.

Unmet needs in treatment of symptomatic uncomplicated diverticular disease and prevention of recurrent acute diverticulitis: a scoping review

Background

Diverticular disease (DD) represents a common gastrointestinal condition that poses a heavy burden on healthcare systems worldwide. A high degree of uncertainty surrounds the therapeutic approaches for the control of symptoms in patients with symptomatic uncomplicated diverticular disease (SUDD) and primary and secondary prevention of diverticulitis and its consequences.

Objectives

To review the current knowledge and discuss the unmet needs regarding the management of SUDD and the prevention of acute diverticulitis.

Eligibility criteria

Randomized trials, observational studies, and systematic reviews on lifestyle/dietary interventions and medical treatment (rifaximin, mesalazine, and probiotics) of SUDD or prevention of acute diverticulitis.

Sources of evidence

The literature search was performed from inception to April 2023, without language restriction, following the modified Preferred Reporting Items for Systematic review and Meta-Analyses (PRISMA) reporting guidelines. References of the papers selected were checked to identify additional papers of potential interest. The final list of references was evaluated by a panel of experts, who were asked to check for any lack of relevant studies.

Charting methods

Information on patient population, study design, intervention, control group, duration of the observation, and outcomes assessed was collected by two authors independently.

Results

The review shows a high degree of uncertainty about therapeutic interventions, both dietary/lifestyle and pharmacological, in patients with SUDD, because of the scarcity and weakness of existing evidence. Available studies are generally of low quality, heterogeneous, and outdated, precluding the possibility to draw robust conclusions. Similarly, acute diverticulitis prevention has been seldom investigated, and there is a substantial lack of evidence supporting the role of dietary/lifestyle or pharmacological approaches to reduce the risk of diverticulitis.

Conclusion

The lack of robust evidence regarding therapeutic options for gastrointestinal symptoms in SUDD patients and for primary and secondary prevention of acute diverticulitis remains an important unmet need in the management of DD.

The potential for development of clinically relevant microbial resistance to rifaximin-α: a narrative review

Rifaximin-α is a gut-targeted antibiotic indicated for numerous gastrointestinal and liver diseases. Its multifaceted mechanism of action goes beyond direct antimicrobial effects, including alterations in bacterial virulence, cytoprotective effects on host epithelial cells, improvement of impaired intestinal permeability, and reduction of proinflammatory cytokine expression via activation of the pregnane X receptor. Rifaximin-α is virtually non-absorbed, with low systemic drug levels contributing to its excellent safety profile. While there are high concentrations of drug in the colon, low water solubility leads to low colonic drug bioavailability, protecting the gut microbiome. Rifaximin-α appears to be more active in the bile-rich small bowel. Its important biologic effects are largely at sub-inhibitory concentration. Although in vitro testing of clinical isolates from rifaximin recipients has revealed rifaximin-resistant strains in some studies, the risk of emergent rifaximin-α resistance appears to be lower than for many other antibiotics. Rifaximin-α has been used for many years for traveler's diarrhea with no apparent increase in resistance levels in causative pathogens. Further, rifaximin-α retains its efficacy after long-term and recurrent usage in chronic gastrointestinal disorders. There are numerous reasons why the risk of microbial resistance to rifaximin-α may be lower than that for other agents, including low intestinal bioavailability in the aqueous colon, the mechanisms of action of rifaximin-α not requiring inhibitory concentrations of drug, and the low risk of cross transmission of rifaximin-α resistance between bacterial species. Reported emergence of vancomycin-resistant Enterococcus in liver-disease patients maintained on rifaximin needs to be actively studied. Further studies are required to assess the possible correlation between in vitro resistance and rifaximin-α efficacy.

The role of microbiota and its modulation in colonic diverticular disease

BACKGROUND

Diverticular disease (DD) is a common condition in Western countries. The role of microbiota in the pathogenesis of DD and its related symptoms has been frequently postulated since most complications of this disease are bacteria-driven and most therapies rely on microbiota modulation. Preliminary data showed fecal microbial imbalance in patients with DD, particularly when symptomatic, with an increase of pro-inflammatory and potentially pathogenetic bacteria. In addition, bacterial metabolic markers can mirror specific pathways of the disease and may be even used for monitoring treatment effects. All treatments currently suggested for DD can affect microbiota structure and metabolome compositions.

PURPOSE

Sparse evidence is available linking gut microbiota perturbations, diverticular disease pathophysiology, and symptom development. We aimed to summarize the available knowledge on gut microbiota evaluation in diverticular disease, with a focus on symptomatic uncomplicated DD, and the relative treatment strategies.

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.

Eubiotic effect of rifaximin is associated with decreasing abdominal pain in symptomatic uncomplicated diverticular disease: results from an observational cohort study

BACKGROUND

Rifaximin effectively treats symptomatic uncomplicated diverticular disease (SUDD) and has shown eubiotic potential (i.e., an increase in resident microbial elements with potential beneficial effects) in other diseases. This study investigated changes in the fecal microbiome of patients with SUDD after repeated monthly treatment with rifaximin and the association of these changes with the severity of abdominal pain.

METHODS

This was a single-center, prospective, observational, uncontrolled cohort study. Patients received rifaximin 400 mg twice a day for 7 days per month for 6 months. Abdominal pain (assessed on a 4-point scale from 0 [no pain] to 3 [severe pain]) and fecal microbiome (assessed using 16 S rRNA gene sequencing) were assessed at inclusion (baseline) and 3 and 6 months. The Spearman's rank test analyzed the relationship between changes in the gut microbiome and the severity of abdominal pain. A p-value ≤ 0.05 was considered statistically significant.

RESULTS

Of the 23 patients enrolled, 12 patients completed the study and were included in the analysis. Baseline abdominal pain levels decreased significantly after 3 (p = 0.036) and 6 (p = 0.008) months of treatment with rifaximin. The abundance of Akkermansia in the fecal microbiome was significantly higher at 3 (p = 0.017) and 6 (p = 0.015) months versus baseline. The abundance of Ruminococcaceae (p = 0.034), Veillonellaceae (p = 0.028), and Dialister (p = 0.036) were significantly increased at 6 months versus baseline, whereas Anaerostipes (p = 0.049) was significantly decreased. The severity of abdominal pain was negatively correlated with the abundance of Akkermansia (r=-0.482; p = 0.003) and Ruminococcaceae (r=-0.371; p = 0.026) but not with Veillonellaceae, Dialister, or Anaerostipes. After 3 months of rifaximin, abdominal pain was significantly less in patients with Akkermansia in their fecal microbiome than in patients without Akkermansia (p = 0.022).

CONCLUSION

The eubiotic effect of rifaximin was associated with decreased abdominal pain in patients with SUDD.

Diverticular Disease and Rifaximin: An Evidence-Based Review

There have been considerable advances in the treatment of diverticular disease in recent years. Antibiotics are frequently used to treat symptoms and prevent complications. Rifaximin, a non-absorbable antibiotic, is a common therapeutic choice for symptomatic diverticular disease in various countries, including Italy. Because of its low systemic absorption and high concentration in stools, it is an excellent medicine for targeting the gastrointestinal tract, where it has a beneficial effect in addition to its antibacterial properties. Current evidence shows that cyclical rifaximin usage in conjunction with a high-fiber diet is safe and effective for treating symptomatic uncomplicated diverticular disease, while the cost-effectiveness of long-term treatment is unknown. The use of rifaximin to prevent recurrent diverticulitis is promising, but further studies are needed to confirm its therapeutic benefit. Unfortunately, there is no available evidence on the efficacy of rifaximin treatment for acute uncomplicated diverticulitis.

Lactobacillus paracasei CNCM I 1572: A Promising Candidate for Management of Colonic Diverticular Disease

Diverticular disease (DD) is a common gastrointestinal condition. Patients with DD experience a huge variety of chronic nonspecific symptoms, including abdominal pain, bloating, and altered bowel habits. They are also at risk of complications such as acute diverticulitis, abscess formation, hemorrhage, and perforation. Intestinal dysbiosis and chronic inflammation have recently been recognized as potential key factors contributing to disease progression. Probiotics, due to their ability to modify colonic microbiota balance and to their immunomodulatory effects, could present a promising treatment option for patients with DD. Lactobacillus paracasei CNCM I 1572 (LCDG) is a probiotic strain with the capacity to rebalance gut microbiota and to decrease intestinal inflammation. This review summarizes the available clinical data on the use of LCDG in subjects with colonic DD.

Updates in the understanding and management of diverticular disease

PURPOSE OF REVIEW

Diverticulosis leads to significant morbidity and mortality and is increasing in prevalence worldwide. In this paper, we review the clinical features, diagnosis, and management of diverticular disorders, followed by a discussion of recent updates and changes in the clinical approach to diverticular disease.

RECENT FINDINGS

Recent literature suggests that antibiotics are likely not necessary for low-risk patients with acute uncomplicated diverticulitis, and not all patients with recurrent diverticulitis require colectomy. Dietary restrictions do not prevent recurrent diverticulitis. Visceral hypersensitivity is increasingly being recognized as a cause of persistent abdominal pain after acute diverticulitis and should be considered along with chronic smoldering diverticulitis, segmental colitis associated with diverticula, and symptomatic uncomplicated diverticular disease.

SUMMARY

Clinicians should be aware that traditionally held assumptions regarding the prevention and management of diverticular disorders have recently been called into question and should adjust their clinical practice accordingly.

The prevalence of symptomatic uncomplicated diverticular disease could be lower than expected: a single-center colonoscopy-based cohort study

AIM

The real prevalence of symptomatic uncomplicated diverticular disease (SUDD) is still unknown. The aim of this study was to assess the prevalence of SUDD, post-diverticulitis SUDD (PD-SUDD) and irritable bowel syndrome (IBS)-like symptoms in a real-life population.

METHODS

A cohort of patients, submitted to colonoscopy from 1st January 2012 to 30th April 2018 was revised.

RESULTS

A cohort of 5451 patients with diverticulosis was identified during the study period. Abdominal pain was recorded in 1141 patients (20.93%), diarrhea in 288 (5.28%) and constipation in 536 (9.83%) patients. SUDD was recorded in 371 patients (6.81% of the patients having diverticulosis and 32.51% of the patients experiencing abdominal pain), PD-SUDD was recorded in 103 patients (1.89% of the patients having diverticulosis and 9.03% of the patients experiencing abdominal pain) and IBS-like was recorded in 348 patients (6.38% of the patients having diverticulosis and 30.5% of the patients experiencing abdominal pain). Three hundred and nineteen patients were not part of any of the previous categories (5.85% of the patients having diverticulosis and 27.96% of the patients experiencing abdominal pain). SUDD and PD-SUDD were more frequent in older ages (>60 years), while IBS-like symptoms were more frequent in younger. Nonspecific abdominal pain was equally distributed in through the ages.

CONCLUSION

The prevalence of SUDD seems to be lower than expected, and most of patients with diverticulosis and abdominal symptoms may suffer from IBS-like or other causes.

Natural History of Ulcerative Colitis with Coexistent Colonic Diverticulosis

Ulcerative colitis (UC) and colonic diverticulosis can co-exist in some patients. However, the natural history of UC associated with colonic diverticulosis is not well known. We here compared the disease characteristics and outcome of UC patients with and without concomitant colonic diverticulosis. Medical records of 347 UC patients were included in an observational, retrospective, nested-matched case-control study. Cases were 92 patients with UC and concomitant colonic diverticulosis, while controls were 255 UC patients without concomitant colonic diverticulosis. A propensity score matching (PSM) was used to homogenate cases (n = 92) and controls (n = 153) for age. UC patients with concomitant colonic diverticulosis were less likely to have an extensive disease (25/92, 27.1%) and to experience steroid dependence (8/92, 8.6%) compared to patients without concomitant colonic diverticulosis (70/153, 45.7% and 48/153, 31.3%, respectively; p < 0.001). The use of immunosuppressants (9/92, 9.7% vs. 37/153, 24.1%; p = 0.007) or biologics (3/92, 3.2% vs. 26/153, 16.9%, p < 0.001) was significantly lower in UC patients with concomitant diverticulosis compared to the control group. On multivariate analysis, steroid dependence and extensive colitis were significantly less frequent in UC patients with concomitant colonic diverticulosis compared to UC patients without diverticula. UC patients with coexisting colonic diverticulosis are less likely to have an extensive disease and to be steroid-dependent.

The natural history of symptomatic uncomplicated diverticular disease: a long-term follow-up study

Background

Symptomatic uncomplicated diverticular disease (SUDD) affects about 20% of patients who have diverticulosis. However, the natural history of SUDD is not yet completely understood. Our aim was to assess the outcomes of a cohort of SUDD patients during a long-term follow up.

Methods

One hundred eighty-five patients suffering from SUDD were identified from a large electronic database. Symptoms assessed were abdominal pain, bloating, bowel movement/day, each of which was scored using a visual analogic scale (VAS); the symptom score was calculated by considering the value of the worst symptom present during assessment. Another VAS was used to assess patients' quality of life (QoL). Patients were treated at the physician's discretion (with rifaximin, mesalazine, probiotics, spasmolytics) only when symptoms occurred during the follow up. Follow-up visit was performed every year or whenever patients consider it necessary.

Results

During the follow up (156 months, interquartile range 9-171), 47 patients were lost to follow up. Among these, 9 died from causes not related to SUDD. Acute diverticulitis occurred in 14 patients (7.6% of the overall population): 6 patients (3.2% of the overall population) underwent surgery, and 2 patients (1.1% of the overall population) died because of peritonitis. Both the symptom score and the QoL score were substantially unmodified during the study period.

Conclusions

SUDD is an important disease able to affect patients significantly in the long term. Acute diverticulitis may sometimes occur in these patients, often leading to surgery with possible severe complications.

Risk factors for endoscopic severity of diverticular disease of the colon and its outcome: a real-life case-control study

BACKGROUND

Diverticular disease is an increasing global problem.

AIMS

To assess the factors associated with the severity of diverticular disease and its outcome, analyzing a real-life population.

METHODS

A cohort of patients, submitted to colonoscopy from 1 January 2012 to 30 April 2018 was revised. The endoscopic severity of diverticular disease was scored according to the Diverticular Inflammation and Complications Assessment (DICA) classification.

RESULTS

A cohort of 11 086 patients was identified during the study period, 5635 with diverticulitis and 5451 without diverticulosis. Blood hypertension, diabetes and angiotensin receptor blocker users occurred more frequently in the study group, while the prevalence of colorectal cancer (CRC) was significantly lower. Age >70 years, BMI >30 and blood hypertension were factors independently related to the presence of diverticulosis, while diabetes and CRC were significantly associated with the absence of diverticulosis. Female sex, age, smoke, appendectomy, proton-pump inhibitors and acetyl-salicylic acid use were directly related to the severity of diverticular disease, while CRC and colonic polyp occurrence were inversely related to the severity of diverticular disease, significantly. Female sex, age >70 years and smoke were significantly related to the severity of diverticular disease. CRC and colonic polyps were significantly less in DICA 3 patients. DICA 3 patients were more often symptomatic, at higher risk of hospital admission, longer hospital stay and higher mean costs.

CONCLUSIONS

Several factors are associated with the severity of diverticular disease according to the DICA classification. The DICA classification is also predictive of the outcome of the disease in terms of hospital admission, stay and costs.

Colonic diverticular disease

Diverticula are outpouchings of the intestinal wall and are common anatomical alterations detected in the human colon. Colonic diverticulosis (the presence of diverticula in the colon; referred to as diverticulosis) remains asymptomatic in most individuals but ~25% of individuals will develop symptomatic diverticulosis, termed colonic diverticular disease (also known as diverticular disease). Diverticular disease can range in severity from symptomatic uncomplicated diverticular disease (SUDD) to symptomatic disease with complications such as acute diverticulitis or diverticular haemorrhage. Since the early 2000s, a greater understanding of the pathophysiology of diverticulosis and diverticular disease, which encompasses genetic alterations, chronic low-grade inflammation and gut dysbiosis, has led to improvements in diagnosis and management. Diagnosis of diverticular disease relies on imaging approaches, such as ultrasonography, CT and MRI, as biomarkers alone are insufficient to establish a diagnosis despite their role in determining disease severity and progression as well as in differential diagnosis. Treatments for diverticular disease include dietary fibre, pharmacological treatments such as antibiotics (rifaximin), anti-inflammatory drugs (mesalazine) and probiotics, alone or in combination, and eventually surgery. Despite being effective in treating primary disease, their effectiveness in primary and secondary prevention of complications is still uncertain.