A randomized double-blind placebo-controlled trial of a multi-strain probiotic in treatment of symptomatic uncomplicated diverticular disease

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.

Effects of a probiotic suspension Symprove™ on a rat early-stage Parkinson's disease model

An increasing number of studies in recent years have focused on the role that the gut may play in Parkinson's Disease (PD) pathogenesis, suggesting that the maintenance of a healthy gut may lead to potential treatments of the disease. The health of microbiota has been shown to be directly associated with parameters that play a potential role in PD including gut barrier integrity, immunity, function, metabolism and the correct functioning of the gut-brain axis. The gut microbiota (GM) may therefore be employed as valuable indicators for early diagnosis of PD and potential targets for preventing or treating PD symptoms. Preserving the gut homeostasis using probiotics may therefore lead to a promising treatment strategy due to their known benefits in improving constipation, motor impairments, inflammation, and neurodegeneration. However, the mechanisms underlying the effects of probiotics in PD are yet to be clarified. In this project, we have tested the efficacy of an oral probiotic suspension, Symprove™, on an established animal model of PD. Symprove™, unlike many commercially available probiotics, has been shown to be resistant to gastric acidity, improve symptoms in gastrointestinal diseases and improve gut integrity in an in vitro PD model. In this study, we used an early-stage PD rat model to determine the effect of Symprove™ on neurodegeneration and neuroinflammation in the brain and on plasma cytokine levels, GM composition and short chain fatty acid (SCFA) release. Symprove™ was shown to significantly influence both the gut and brain of the PD model. It preserved the gut integrity in the PD model, reduced plasma inflammatory markers and changed microbiota composition. The treatment also prevented the reduction in SCFAs and striatal inflammation and prevented tyrosine hydroxylase (TH)-positive cell loss by 17% compared to that observed in animals treated with placebo. We conclude that Symprove™ treatment may have a positive influence on the symptomology of early-stage PD with obvious implications for the improvement of gut integrity and possibly delaying/preventing the onset of neuroinflammation and neurodegeneration in human PD patients.

Microbiota Composition in Diverticular Disease: Implications for Therapy

Gut microbiota (GM) composition and its imbalance are crucial in the pathogenesis of several diseases, mainly those affecting the gastrointestinal tract. Colon diverticulosis and its clinical manifestations (diverticular disease, DD) are among the most common digestive disorders in developed countries. In recent literature, the role of GM imbalance in the onset of the different manifestations within the clinical spectrum of DD has been highlighted. This narrative review aims to summarize and critically analyze the current knowledge on GM dysbiosis in diverticulosis and DD by comparing the available data with those found in inflammatory bowel disease (IBD). The rationale for using probiotics to rebalance dysbiosis in DD is also discussed.

Evaluation and Management After Acute Left-Sided Colonic Diverticulitis : A Systematic Review

BACKGROUND

The value of interventions used after acute colonic diverticulitis is unclear.

PURPOSE

To evaluate postdiverticulitis colonoscopy and interventions to prevent recurrent diverticulitis.

DATA SOURCES

MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase, CINAHL, and ClinicalTrials.gov from 1 January 1990 through 16 November 2020.

STUDY SELECTION

Comparative studies of interventions of interest reporting critical or important outcomes, and larger single-group studies to evaluate prevalence of colonoscopy findings and harms.

DATA EXTRACTION

6 researchers extracted study data and risk of bias. The team assessed strength of evidence.

DATA SYNTHESIS

19 studies evaluated colonoscopy. Risk for prevalent colorectal cancer (CRC) compared with the general population is unclear. Based on low-strength evidence, long-term CRC diagnosis is similar with or without colonoscopy. High-strength evidence indicates that risk for prevalent CRC is higher among patients with complicated diverticulitis and colonoscopy complications are rare. Based on high-strength evidence, mesalamine does not reduce recurrence risk (6 randomized controlled trials [RCTs]). Evidence on other nonsurgical interventions is insufficient. For patients with prior complicated or smoldering or frequently recurrent diverticulitis, elective surgery is associated with reduced recurrence (3 studies; high strength). In 19 studies, serious surgical complications were uncommon.

LIMITATIONS

Few RCTs provided evidence. Heterogeneity of treatment effect was not adequately assessed.

CONCLUSION

It is unclear whether patients with recent acute diverticulitis are at increased risk for prevalent CRC, but those with complicated diverticulitis are at increased risk. Mesalamine is ineffective in preventing recurrence; other nonsurgical treatments have inadequate evidence. Elective surgery reduces recurrence in patients with prior complicated or smoldering or frequently recurrent diverticulitis, but it is unclear which of these patients may benefit most.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality and American College of Physicians. (PROSPERO: CRD42020151246).

Colonoscopy for Diagnostic Evaluation and Interventions to Prevent Recurrence After Acute Left-Sided Colonic Diverticulitis: A Clinical Guideline From the American College of Physicians

DESCRIPTION

The American College of Physicians (ACP) developed this guideline to provide clinical recommendations on the role of colonoscopy for diagnostic evaluation of colorectal cancer (CRC) after a presumed diagnosis of acute left-sided colonic diverticulitis and on the role of pharmacologic, nonpharmacologic, and elective surgical interventions to prevent recurrence after initial treatment of acute complicated and uncomplicated left-sided colonic diverticulitis. This guideline is based on the current best available evidence about benefits and harms, taken in the context of costs and patient values and preferences.

METHODS

The ACP Clinical Guidelines Committee (CGC) based these recommendations on a systematic review on the role of colonoscopy after acute left-sided colonic diverticulitis and pharmacologic, nonpharmacologic, and elective surgical interventions after initial treatment. The systematic review evaluated outcomes rated by the CGC as critical or important. This guideline was developed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) method.

TARGET AUDIENCE AND PATIENT POPULATION

The target audience is all clinicians, and the target patient population is adults with recent episodes of acute left-sided colonic diverticulitis.

RECOMMENDATION 1

ACP suggests that clinicians refer patients for a colonoscopy after an initial episode of complicated left-sided colonic diverticulitis in patients who have not had recent colonoscopy (conditional recommendation; low-certainty evidence).

RECOMMENDATION 2

ACP recommends against clinicians using mesalamine to prevent recurrent diverticulitis (strong recommendation; high-certainty evidence).

RECOMMENDATION 3

ACP suggests that clinicians discuss elective surgery to prevent recurrent diverticulitis after initial treatment in patients who have either uncomplicated diverticulitis that is persistent or recurs frequently or complicated diverticulitis (conditional recommendation; low-certainty evidence). The informed decision whether or not to undergo surgery should be personalized based on a discussion of potential benefits, harms, costs, and patient's preferences.

Influence of probiotic bacteria on gut microbiota composition and gut wall function in an in-vitro model in patients with Parkinson's disease

We report here the potential role of a 4-strain probiotic suspension for use with patients with Parkinson's disease (PD). Stool samples from a group of three patients with diagnosed PD were used to create microbiotas in an in-vitro gut model. The effects of dosing with an oral probiotic suspension (Symprove) on bacterial composition and metabolic activity in the microbiotas was evaluated over 48 h and compared with healthy controls. Additionally, the effect of probiotic dosing on epithelial tight-junction integrity, production of inflammatory markers and wound healing were evaluated in cell culture models. In general, the relative proportions of the main bacterial phyla in the microbiotas of PD patients differed from those of healthy subjects, with levels of Firmicutes raised and levels of Bacteroidetes reduced. Dosing with probiotic resulted in a change in bacterial composition in the microbiotas over a 48 h period. Several other indicators of gut health changed upon dosing with the probiotic; production of short chain fatty acids (SCFAs) and lactate was stimulated, levels of anti-inflammatory cytokines (IL-6, IL-10) increased and levels of pro-inflammatory cytokines and chemokines (MCP-1 and IL-8) decreased. Tight junction integrity was seen to improve with probiotic dosing and wound healing was seen to occur faster than a control. The data suggest that if development and/or progression of PD is influenced by gut microbiota dysbiosis then supplementation of the diet with a properly formulated probiotic may be a useful adjunct to standard treatment in clinic.

Kinetic analysis of microcalorimetric data derived from microbial growth: Basic theoretical, practical and industrial considerations

We report here a mathematical framework for the quantitative interpretation of exponential bacterial growth measured with isothermal microcalorimetry. The method allows determination of many parameters that define the exponential growth phase. To automate the analysis, we also wrote a coding program, so that the approach could be embedded in a commercial setting. As an exemplar, we apply the method to a commercial probiotic product. The outcome was that we could identify characteristic parameters of growth (including rate constant and doubling time), and hence authenticate product quality, within 15 h. This compares favourably with the current 7-10 days required for conventional microbiological assessment (to allow release of product for bottling and marketing) via plating methods. The method would lend itself to growth analysis of single and mixed bacterial cultures.

Gastrointestinal dysfunction in Parkinson's disease: molecular pathology and implications of gut microbiome, probiotics, and fecal microbiota transplantation

Gastrointestinal symptoms and gut dysbiosis may occur before the onset of motor symptoms in Parkinson's disease (PD). Prediagnostic and prodromal features, such as constipation and α-synuclein pathology, can be detected several years before the clinical diagnosis of PD and have the potential to develop as early PD biomarkers. Environmental toxins and gut dysbiosis may trigger oxidative stress and mucosal inflammation, and initiate α-synuclein accumulation in the enteric nervous system, early in PD. Chronic gut inflammation can lead to a leaky gut and systemic inflammation, neuro inflammation, and neuro degeneration via gut-vagus-brain signaling or through blood-brain barrier permeability. Concepts regarding the gut-brain signaling in PD pathogenesis are changing rapidly and more investigation is required. The gut microbiota interacts with the human body by modulating the enteric and central nervous systems, and immune activity. Understanding the immune responses between gut microbiota and human body might help in elucidating the PD pathogenesis. As changes in gut microbiota composition might be associated with different clinical phenotypes of PD, gut microbiota-modulating interventions, such as probiotics and fecal microbiota transplantation (FMT), have the potential to restore the gut dysbiosis, reduce inflammation, and possibly modulate the clinical PD phenotype.

Management of symptomatic uncomplicated diverticular colon disease: A systematic review of diagnosis and treatment

Symptomatic uncomplicated diverticular colon disease (SUDCD) is a highly prevalent disease in our setting, which significantly affects the quality of life of patients. Recent changes in understanding the natural history of this disease and technological and pharmacological advances have increased the available options for both diagnosis and treatment. However, consensus regarding the use of these options is scarce and sometimes lacks scientific evidence. The objective of this systematic review is to clarify the existing scientific evidence and analyse the use of the different diagnostic and therapeutic options for SUDCD, comparing their advantages and disadvantages, to finally suggest a diagnostic-therapeutic algorithm for this pathology and, at the same time, propose new research questions.

A 4-strain probiotic supplement influences gut microbiota composition and gut wall function in patients with ulcerative colitis

Symprove, a multi-strain probiotic, has been shown to exert a mild anti-inflammatory effect in patients with ulcerative colitis (UC). We examined stool samples from 3 patients with UC in order to create microbiotas in an in-vitro gut model. The effects of Symprove on bacterial diversity and metabolic activity in the microbiotas was evaluated over 48 h. In addition, the influence of probiotic dosing on epithelial tight-junction integrity, production of inflammatory markers and wound healing were evaluated in cell culture models. The relative proportions of the main bacterial phyla in UC patients differed from those of healthy subjects studied previously; levels of Firmicutes were lowered and levels of Bacteroidetes were raised. Addition of Symprove changed the bacterial composition in the microbiotas over a 48 h period. Several other factors generally implicated in good gut health changed after dosing with probiotic; production of short chain fatty acids (SCFAs) and lactate was stimulated, levels of anti-inflammatory cytokines (IL-6, IL-10) increased, levels of pro-inflammatory cytokines and chemokines (MCP-1 and IL-8) decreased, epithelial tight junction integrity improved and wound healing occurred faster than a control. The results imply it is not the simple addition of probiotic bacteria that improves gut health. Rather, the probiotic bacteria generate lactate, which then stimulates growth of commensal gut bacteria, raising SCFA levels (particularly butyrate). The increased butyrate concentration positively influences inflammation response and time of wound healing.

Microbiota modulation-based therapy for luminal GI disorders: current applications of probiotics and fecal microbiota transplantation

Introduction: Alteration in the intestinal microbiota also termed as intestinal dysbiosis has been demonstrated in numerous gastrointestinal disorders linked to aberrant immune processes, acquisition of pathogenic organisms and often administration of antibiotics. Restoration of microbiota through probiotics and fecal microbiota transplantation (FMT) has gained tremendous popularity among researchers in the prevention and treatment of gastrointestinal diseases.Areas covered: In this review, studies testing the safety and efficacy of probiotics and FMT for the treatment of various infectious and inflammatory luminal gastrointestinal diseases are reviewed. Randomized control studies are given priority while important uncontrolled studies are also highlighted.Expert opinion: Probiotics have demonstrated efficacy in the prevention of antibiotic-associated diarrhea and in the eradication of Helicobacter pylori infection. Their utility in the primary and secondary prevention of Clostridioides difficile infection is debatable. The future of medicine should bring forth a personalized approach to probiotic use. FMT has revolutionized the treatment of recurrent CDI as well as severe and fulminant CDI. At the same time, it has galvanized gut microbiota research in the last decade. While FMT in ulcerative colitis appears promising, further studies on the durability and long-term safety are needed before it can be recommended in clinical practice.

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.

Supplementation with Lactobacillus reuteri ATCC PTA 4659 in patients affected by acute uncomplicated diverticulitis: a randomized double-blind placebo controlled trial

INTRODUCTION

Acute uncomplicated diverticulitis (AUD) is an inflammation of the colon diverticulum. We tested the efficacy of Lactobacillus reuteri 4659 (L. reuteri) in treating AUD. Primary outcome was reduced abdominal pain and inflammatory markers (C-RP). Secondary outcome was reduced hours of hospitalization.

PATIENTS AND METHODS

A double-blind, placebo RCT was conducted with 88 (34M/54F mean age 61.9 ± 13.9) patients with a diagnosis of AUD. Group A (44 patients, 26F): ciprofloxacin 400 mg/bid and metronidazole 500 mg/tid for 1 week, plus L. reuteri/bid for 10 days. Group B (44 patients, 28F): same antibiotic therapy for 1 week, plus placebo/bid for 10 days. All patients completed a daily visual analog scale (VAS) for abdominal pain.

RESULTS

Between days 1 and 3, the group A pain decreased by 4.5 points; group B decreased by 2.36 points (p < 0.0001). Between days 1 and 5, the group A decreased by 6.6 points; group B by 4.4 points (p < 0.0001). Between days 1 and 7, the group A decreased by 7.6 points; group B decreased by 5.6 points (p < 0.0001). Between days 1 and 10, the group A decreased by 8.1 points; group B decreased by 6.7 points (p < 0.0001). For C-RP value, the mean decrease between admission and after 72 h was 45.3 mg/L for group A and 27.49 mg/L for group B (p < 0.0001).

CONCLUSIONS

Our RCT showed that supplementation of the standard AUD therapy with L. reuteri strain 4659 significantly reduced abdominal pain and inflammatory markers compared with the placebo group. It also resulted in a shorter period of hospitalization, and thus has economic benefits.

TRIAL REGISTRATION

TRIALGOV: NCT03656328.

A randomised, double-blind, placebo-controlled trial of a multi-strain probiotic in patients with asymptomatic ulcerative colitis and Crohn's disease

Background

There is considerable interest in the possible importance of the gut microflora in the pathophysiology of the inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn’s disease (CD). Probiotics offer a potential adjuvant treatment in these patients by modifying the intestinal milieu, but reports of their efficacy are conflicting.

Aims

To assess the efficacy of a multi-strain probiotic (Symprove™, Symprove Ltd, Farnham, United Kingdom) in quality of life issues and intestinal inflammation in patients with asymptomatic UC and CD.

Methods

A single-centre, randomised, double-blind, placebo-controlled trial of adult patients with asymptomatic IBD. Patients received 4 weeks of treatment with the probiotic or placebo (1 ml/kg/day). The primary efficacy measure was the difference in change in the IBD Quality of Life Questionnaire results (QOL) between probiotic vs. placebo at week 4. Secondary outcome measures included analyses of the change in laboratory findings, including faecal calprotectin (FCAL).

Results

Over 500 patients were recruited to the study and 81 and 61 patients with UC and CD, respectively were randomised and completed the study. There were no significant differences in IBD-QOL scores between placebo and the probiotic groups. Similarly, there were no significant changes observed in the laboratory data. However, the differences in FCAL between patients with UC before and after probiotics versus placebo approached statistical significance with a p value of 0.076. Post-hoc analyses showed that the FCAL levels were significantly (p < 0.015) reduced in the UC patients receiving the probiotic as opposed to placebo. No significant changes were seen in CD. No serious adverse events were observed.

Conclusion

This multi-strain probiotic is associated with decreased intestinal inflammation in patients with UC, but not in CD and is well tolerated. Further research is required to see if the probiotic reduces the incidence of clinical relapses in asymptomatic IBD patients.

Use of a water-based probiotic to treat common gut pathogens

This work reports the anti-pathogenic effect of a commercially available water-based probiotic suspension, Symprove™, against three commonly encountered infectious organisms; Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA) and Shigella sonnei. An isothermal calorimetric assay was used to the monitor growth of the species individually and in binary combinations, while colony plate counting was used to enumerate viable cell numbers. It was observed that all pathogenic species were faster growing than the probiotic bacteria in Symprove™ after inoculation into growth medium yet in all instances bacterial enumeration at the end of the experiments revealed a significant reduction in the pathogen population compared with the controls. A control population between 10⁸ and 10⁹ CFU/ml was obtained for E. coli and S. sonnei whilst approximately 10⁶ CFU/ml was obtained for MRSA. Upon co-incubation for 48 h, no viable counts were obtained for E. coli; a 4-log reduction was obtained for S. sonnei whilst MRSA numbers were down to less than 10 cells/ml. The results show that Symprove™ has antipathogenic activity against E. coli, S. sonnei and MRSA.

A four-strain probiotic exerts positive immunomodulatory effects by enhancing colonic butyrate production in vitro

Poorly formulated probiotic supplements intended for oral administration often fail to protect bacteria from the challenges of human digestion, meaning bacteria do not reach the small intestine in a viable state. As a result, the ability of probiotics to influence the human gut microbiota has not been proven. Here we show how (i) considered formulation of an aqueous probiotic suspension can facilitate delivery of viable probiotic bacteria to the gut and (ii) quantitate the effect of colonisation and proliferation of specific probiotic species on the human gut microbiota, using an in-vitro gut model. Our data revealed immediate colonisation and growth of three probiotic species in the luminal and mucosal compartments of the proximal and distal colon, and growth of a fourth species in the luminal proximal colon, leading to higher proximal and distal colonic lactate concentrations. The lactate stimulated growth of lactate-consuming bacteria, altering the bacterial diversity of the microbiota and resulting in increased short-chain fatty acid production, especially butyrate. Additionally, an immunomodulatory effect of the probiotics was seen; production of anti-inflammatory cytokines (IL-6 and IL-10) was increased and production of inflammatory chemokines (MCP-1, CXCL 10 and IL-8.) was reduced. The results indicate that the probiotic species alone do not result in a clinical effect; rather, they facilitate modulation of the gut microbiota composition and metabolic activity thereby influencing the immune response.

Diverticulosis today

The incidence of diverticulosis and diverticular disease of the colon is increasing worldwide. Although the majority of patients remains asymptomatic long-life, the prevalence of diverticular disease of the colon, including acute diverticulitis, is substantial and is becoming a significant burden on National Health Systems in terms of direct and indirect costs. Fiber, non-absorbable antibiotics and probiotics seem to be effective in treating symptomatic and uncomplicated patients, and 5-aminosalicylic acid might help prevent acute diverticulitis. Unfortunately, robust evidence on the effectiveness of a medical strategy to prevent acute diverticulitis recurrence is still lacking. Focus is now being drawn on identifying a new endoscopic classification of the disease to evaluate the correct therapeutic approach by testing various treatments.

The New Frontier: the Intestinal Microbiome and Surgery

The microbiome exerts a remarkable effect on human physiology. The study of the human-microbiome relationship is a burgeoning field with great potential to improve our understanding of health and disease. In this review, we address common surgical problems influenced by the human microbiome and explore what is thus far known about this relationship. These include inflammatory bowel disease, colorectal neoplasms, and diverticular disease. We will also discuss the effect of the microbiome on surgical complications, specifically anastomotic leak. We hope that further research in this field will enlighten our management of these and other surgical problems.