Prevention of infectious complications in surgical patients: potential role of probiotics

Efficacy of Using Probiotics with Antagonistic Activity against Pathogens of Wound Infections: An Integrative Review of Literature

The skin and its microbiota serve as physical barriers to prevent invasion of pathogens. Skin damage can be a consequence of illness, surgery, and burns. The most effective wound management strategy is to prevent infections, promote healing, and prevent excess scarring. It is well established that probiotics can aid in skin healing by stimulating the production of immune cells, and they also exhibit antagonistic effects against pathogens via competitive exclusion of pathogens. Our aim was to conduct a review of recent literature on the efficacy of using probiotics against pathogens that cause wound infections. In this integrative review, we searched through the literature published in the international following databases: PubMed, ScienceDirect, Web of Science, and Scopus using the search terms “probiotic” AND “wound infection.” During a comprehensive review and critique of the selected research, fourteen in vitro studies, 8 animal studies, and 19 clinical studies were found. Two of these in vitro studies also included animal studies, yielding a total of 39 articles for inclusion in the review. The most commonly used probiotics for all studies were well-known strains of the species Lactobacillus plantarum, Lactobacillus casei, Lactobacillus acidophilus, and Lactobacillus rhamnosus. All in vitro studies showed successful inhibition of chosen skin or wound pathogens by the selected probiotics. Within the animal studies on mice, rats, and rabbits, probiotics showed strong opportunities for counteracting wound infections. Most clinical studies showed slight or statistically significant lower incidence of surgical site infections, foot ulcer infection, or burn infections for patients using probiotics. Several of these studies also indicated a statistically significant wound healing effect for the probiotic groups. This review indicates that exogenous and oral application of probiotics has shown reduction in wound infections, especially when used as an adjuvant to antibiotic therapy, and therefore the potential use of probiotics in this field remains worthy of further studies, perhaps focused more on typical skin inhabitants as next-generation probiotics with high potential.

Infection dynamics of Toxoplasma gondii in gut-associated tissues after oral infection: The role of Peyer's patches

Toxoplasma gondii is a common perorally transmitted parasite; however, its immunopathogenesis in gut-associated tissues remains unclear. Here, we compared disease manifestation in C57BL/6 immunocompetent wild type (WT) mice and immunocompromised interferon (IFN)-γ-deficient (GKO) mice after peroral infection (PI) with T. gondii cysts (Fukaya strain). Strong PI-induced Th1 cytokine expression was detected in WT mice. Moreover, bradyzoite-specific T.g.HSP30/bag1 mRNA was detected in the ileum parenchyma and Peyer's patches (PP), but not in the mesenteric lymph nodes, at 7 days post-infection in WT mice, and was significantly higher than that in GKO mice. Nested PCR showed that parasites existed in ileum parenchyma at days 1 and 1.5 post-PI in GKO and WT mice, respectively. In addition, quantitative competitive-PCR indicated that T. gondii first colonized the PP (day 3 post-PI), followed by the ileum parenchyma and mesenteric lymph nodes, spleen, and portal and aortic blood (day 7 post-PI). Although parasites were consistently more abundant in GKO mice, similar invasion and dissemination patterns were observed in the two hosts. Collectively, these data suggest that some zoites differentiate from tachyzoites to bradyzoites in the ileum and that T. gondii initially invades the ileum parenchyma, and then accumulates and proliferates in the PP before disseminating through the lymphatic systems of both GKO and WT hosts.

The administration of probiotics and synbiotics in immune compromised adults: is it safe?

This study aimed to systematically evaluate safety of probiotics and synbiotics in immune compromised adults (≥18 years). Safety was analysed using the Common Terminology Clinical Adverse Events (CTCAE version 4.0) classification, thereby providing an update on previous reports using the most recent available clinical data (2008-2013). Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. Analysis of 57 clinical studies indicates that probiotic and/or synbiotic administration in immune compromised adults is safe with regard to the current evaluated probiotic strains, dosages and duration. Individuals were considered immune compromised if HIV-infected, critically ill, underwent surgery or had an organ- or an autoimmune disease. There were no major safety concerns in the study, as none of the serious adverse events (AE)s were related, or suspected to be related, to the probiotic or synbiotic product and the study products were well tolerated. Overall, AEs occurred less frequent in immune compromised subjects receiving probiotics and/or synbiotics compared to the control group. In addition, the results demonstrated a flaw in precise reporting and classification of AE in most studies. Furthermore, generalisability of conclusions are greatly limited by the inconsistent, imprecise and potentially incomplete reporting as well as the variation in probiotic strains, dosages, administration regimes, study populations and reported outcomes. We argue that standardised reporting on adverse events (CTCAE) in 'food' studies should be obligatory, thereby improving reliability of data and re-enforcing the safety profile of probiotics.

Effects of probiotic supplementation on markers of acute pancreatitis in rats

BACKGROUND

Intestinal barrier disruption followed by bacterial translocation seems to play a role in secondary pancreatic infection in acute pancreatitis. The use of probiotics as a possible adjuvant strategy in the treatment of acute pancreatitis needs to be investigated.

OBJECTIVE

The aim of this study was to determine the effects of dietary supplementation with a prophylactically administered multispecies probiotic mixture on the markers of acute pancreatitis and on the occurrence of bacterial translocation.

METHODS

Thirty adult male Wistar rats were randomly assigned to 1 of 3 groups of 10 rats each: (1) the PS group, in which the rats were given probiotic supplementation prior to induction of acute pancreatitis; (2) the WP group, in which the rats underwent surgery to induce acute pancreatitis without prior probiotic supplementation; and (3) the control group, in which the rats underwent sham surgery. For 14 days before surgery, animals in the PS group received a single daily dose containing ~1.2 × 10(9) colony-forming units of a probiotic mixture administered intragastrically as a bolus. On day 15, the animals underwent surgery to induce acute pancreatitis (PS and WP groups) or simulated surgery (control group). Blood samples were collected to determine leukocyte count, amylase and lipase activities, and glucose and calcium concentrations immediately before and 6 and 12 hours after the beginning of the procedure. Samples of pancreas, spleen, liver, and mesenteric lymph nodes were harvested for microbiologic and histopathologic analysis after the last blood sample collection. The pathologist examining the histopathology was blinded to treatment assignment.

RESULTS

The mean leukocyte count was significantly increased in the PS group compared with the WP group (P = 0.018), whereas the serum amylase and lipase activities and the serum glucose and calcium concentrations were not significantly different between the 2 groups. Comparing the risk for tissue colonization in the PS group with that of the WP group, the odds ratio (OR) for pancreas was 2.91 (95% CI, 0.13-67.10); liver, 66.55 (95% CI, 1.89-2282.66); spleen, 88.58 (95% CI, 3.04-2583.08); and mesenteric lymph nodes, 1.23 (95% CI, 0.06-25.48). When the risks for histopathologic changes were compared between the 2 groups, the OR for acinar necrosis was 1.73 (95% CI, 0.21-12.17); steatonecrosis, 12.08 (95% CI, 1.26-115.54); hemorrhage, 1.38 (95% CI, 0.21-9.53); and leukocyte infiltration, 5.91 (95% CI, 0.64-54.89).

CONCLUSION

Probiotic supplementation before the induction of acute pancreatitis was associated with a greater degree of bacterial translocation and pancreatic tissue damage in this animal model.

Gut bacterial translocation is associated with microinflammation in end-stage renal disease patients

AIM

To investigate whether gut bacteria translocation occurs in end-stage renal disease patients and contributes to microinflammation in end-stage renal disease (ESRD).

METHODS

The subjects were divided into two groups: nondialysed ESRD patients (n = 30) and healthy controls (n = 10). Blood samples from all participants were subjected to bacterial 16S ribosomal DNA amplification and DNA pyrosequencing to determine the presence of bacteria, and the alteration of gut microbiomes were examined with the same methods. High-sensitive C-reactive protein and interleukin-6 were detected. Plasma D-lactate was tested for gut permeability.

RESULTS

Bacterial DNAs were detected in the blood of 20% (6/30) of the ESRD patients. All the observed genera in blood (Klebsiella spp, Proteus spp, Escherichia spp, Enterobacter spp, and Pseudomonas spp) were overgrown in the guts of the ESRD patients. Plasma D-lactate, High-sensitive C-reactive protein, and interleukin-6 levels were significantly higher in patients with bacterial DNA than those without. The control group showed the same results as that of patients without bacterial DNA.

CONCLUSION

Bacterial translocation occurs in ESRD patients and is associated with microinflammation in end stage renal disease.

Probiotics, prebiotics, synbiotics: is there enough evidence to support their use in colorectal cancer surgery?

BACKGROUND/AIMS

Pro-/pre-/synbiotics supplementation seems to provide beneficial effects in various aspects of abdominal pathology. Skepticism exists with respect to their effects on colorectal cancer (CRC) patients. This review presents the potential clinical applications of pro-/pre-/synbiotics in CRC surgery.

METHODS

A literature search of electronic databases was conducted and all studies published on 'probiotics', 'prebiotics' and 'synbiotics' were collected. Among them, the ones referring to CRC and which had any clinical relevance offering information on perioperative parameters were used.

RESULTS

Incorporation of pre-/pro-/synbiotic formulations in the preoperative mechanical bowel preparation cannot be supported by the current evidence. Limited clinical studies may be promising in supporting their potentially protective role against postoperative infectious complications. Encouraging are the results on their protective role against adjuvant (chemo)radiation-induced diarrhea. Such supplementation may also hold promise to improve postcolectomy gastrointestinal related quality of life.

CONCLUSIONS

Despite the positive results and plethora of agents, bacterial combinations and concentrations, the inconsistency in administration, the inhomogeneity of comparison groups and lack of stringent clinical endpoints remain obstacles in the effort to establish a definitive clinical strategy at this time. Further work is warranted to gain a keen understanding of their clinical value in CRC patients.

Structural shifts of fecal microbial communities in rats with acute rejection after liver transplantation

Bacterial translocation and the development of sepsis after orthotopic liver transplantation (OLT) may be promoted by immunological damage to the intestinal mucosa or by quantitative and qualitative changes in intestinal microbiota. This study monitored structural shifts of gut microbiota in rats with OLT using PCR-denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR (RT-qPCR). RT-qPCR targets six major microorganisms (Domain Bacteria, Bacteroides, Bifidobacteria, Enterobacteriaceae, Lactobacillus and Clostridium leptum subgroup). Isograft, Allograft and Sham model were studied. Bacterial translocation to host organs and plasma endotoxin were determined. Alteration in gut microbiota was associated with the elevation of plasma endotoxin and a higher rate of bacterial translocation (BT) to liver in rats with acute rejection. Dynamic analysis of DGGE fingerprints showed that the gut microbiota structure of animals in the three groups was similar before the operation. But significant alterations in the composition of fecal microbiota in Allograft group were observed at 1 and 2 weeks after the OLT. The acute rejection was accompanied by the shifts of gut microbiota towards members of Bacteroides and Ruminococcus. Results from RT-qPCR indicated that Bacteroides significantly increased at 2 weeks after the OLT, whereas numbers of Bifidobacterium spp. decreased at 1 week and recovered at 2 weeks after the OLT. In summary, our data showed that rats with acute rejection after OLT exhibited significant structure shifts in the gut microbiota which dominant by overgrowth of Bacteroides and Ruminococcus, and these were associated with elevation of plasma endotoxin and higher rate of BT.

Preoperative probiotics decrease postoperative infectious complications of colorectal cancer

BACKGROUND

The objective is to elucidate the effects of oral bifid triple viable probiotics among patients with colorectal cancer.

METHODS

Sixty patients undergoing radical colorectal resection were randomly assigned to 3-day (days -5 to -3) preoperative probiotics (group A, n = 30) or placebo (group B, n = 30) treatment. The alteration of intestinal flora was evaluated by fecal cultures of Escherichia coli, Bifidobacterium longum and intestinal fungi; the gut barrier function by serum endotoxins and D-lactic acids and the immune and stress responses by peripheral blood immunoglobins, interleukin-6 and C-reactive protein. Postoperative infections were documented physically, radiologically and microbiologically.

RESULTS

Inverted Bifidobacterium/Escherichia ratios were preoperatively and postoperatively present in group B (both P < 0.05). Bifidobacterium counts increased significantly, whereas Escherichia counts decreased significantly on postoperative days 3 to 5 (P < 0.05), along with reversing the Bifidobacterium/Escherichia ratio inversion until postoperative days 3 to 5 in group A. Group A also had lower levels of endotoxins, D-lactic acids, serum interleukin-6 and C-reactive protein but higher levels of serum IgG and sIgA (all P < 0.05) than group B. The incidences of postoperative infectious complications were 3.3% to 6.7% and 3.3% to 30% in groups A and B (overall, 10.0% versus 33.3%, P < 0.05), respectively.

CONCLUSION

The preoperative oral bifid triple viable probiotics minimize the postoperative occurrence of infectious complications, with possible mechanisms attributed to the maintenance of the intestinal flora and restriction of bacterial translocation from the intestine. It was representative of the enhancement of systemic/localized immunity and concurrent attenuation of systemic stress response.

Probiotic acidified formula in an animal model reduces pulmonary and gastric bacterial load

BACKGROUND/PURPOSE

We previously reported that a diet acidified with citric acid effectively reinforces gastric acid protection against bacterial colonization and translocation. In this study, our objective was to examine a biologically acidified formula hypothesized to be more physiologic than formula acidified with free acid. This study was Institutional Animal Care and Use Committee (IACUC) approved and designed to determine whether this diet is better tolerated and equally effective to acidification with citric acid against gut colonization and subsequent bacterial translocation in a premature infant rabbit model.

METHODS

A total of 89 rabbit pups born via cesarean delivery 1 day preterm were randomly assigned to 3 feeding groups: Pelargon Nestle at pH 4.55; NAN Nestle, a control diet at pH 7.0 with similar composition; and NAN Nestle acidified in the laboratory with citric acid at pH 4.55. Pups were gavage fed every 12 hours with Enterobacter cloacae challenges of 10 colony-forming units per milliliter of diet per feed and killed on day 3 of life. Lungs, liver, spleen, mesenteric lymph nodes, stomach, and cecum were cultured and quantitatively analyzed for target organism growth and statistically analyzed using chi(2) and Kruskal-Wallis tests.

RESULTS

Pelargon, compared to acidified NAN and NAN, significantly reduced the incidence of gastric colonization (15/33 [45%], 21/27 [78%], and 25/29 [86%], respectively; P < .01) and pulmonary colonization (10/33 [30%], 19/27 [70%], 21/29 [72%]; P < .01). Comparing the bacterial logs of colonized groups, the same benefit is observed in the lungs (0.77 +/- 1.22, 1.89 +/- 1.41, 2.12 +/- 1.47; P < .01). Gut colonization and bacterial translocation were equivalent between treatment groups (mesenteric lymph nodes: 10/33 [30%], 11/27 [40%], 8/29 [27%]; spleen: 10/33 [30%], 7/27 [26%], 8/29 [27%]; liver: 10/33 [30%], 6/27 [22%], 9/29 [31%]; cecum: 33/33 [100%], 27/27 [100%], 29/29 [100%]).

CONCLUSION

Biologically acidified formula demonstrated superior protection against pulmonary and gastric colonization compared to normal pH and diets acidified with free acid. Its effects may potentially reduce clinical pulmonary infection.

Probiotics and severe acute pancreatitis

Acute pancreatitis (AP) is an acute inflammatory process ranging from mild forms to severe disease with high rates of mortality. In this disease, enteral nutrition helps in maintaining the integrity of the gut barrier, with consequent decreased bacterial translocation, a key factor in limiting the complications in severe AP. Modulation of the intestinal flora through the administration of probiotics (PBs) has thus an intriguing rationale as possible treatment option. Their role in this setting has been investigated both in animal models and clinical trials in the last few years; however, their use has never been recommended or even cited by existing guidelines. We analyzed the literature in search of the existing data from human and animal models studies evaluating the effect of PB administration in AP to highlight existing evidence. An interesting scenario emerges from the the papers that have been evaluated. The adjunct of PBs in the treatment of AP may show some advantage in terms of the reduction of infectious complications. Nevertheless, more data on efficacy and safety from a larger and stringently designed study are eagerly waited.

Role of the intestinal barrier in inflammatory bowel disease

A critical function of the intestinal mucosa is to form a barrier that separates luminal contents from the interstitium. The single layer of intestinal epithelial cells (IECs) serves as a dynamic interface between the host and its environment. Cell polarity and structural properties of the epithelium is complex and is important in the development of epithelial barrier function. Epithelial cells associate with each other via a series of intercellular junctions. The apical most intercellular junctional complex referred to as the Apical Junction Complex (AJC) is important in not only cell-cell recognition, but also in the regulation of paracellular movement of fluid and solutes. Defects in the intestinal epithelial barrier function have been observed in a number of intestinal disorders such as inflammatory bowel disease (IBD). It is now becoming evident that an aberrant epithelial barrier function plays a central role in the pathophysiology of IBD. Thus, a better understanding of the intestinal epithelial barrier structure and function in healthy and disease states such as IBD will foster new ideas for the development of therapies for such chronic disorders.

Antimicrobial activity of a multispecies probiotic (Ecologic 641) against pathogens isolated from infected pancreatic necrosis

AIMS

Although probiotic prophylaxis has been suggested to prevent small bowel bacterial overgrowth, bacterial translocation and infection of pancreatic necrosis in severe acute pancreatitis, limited data are available on their antimicrobial activity.

METHODS AND RESULTS

Using the well-diffusion method, we studied the antimicrobial properties of a multispecies probiotic product (Ecologic 641) against a collection of pathogens cultured from infected pancreatic necrosis. All individual probiotic strains included in the multispecies preparation were able to inhibit the growth of the pathogens to some extent. However, the combination of the individual strains (i.e. the multispecies preparation) was able to inhibit all pathogenic isolates. Probiotic-free supernatants adjusted to pH 7 were not able to inhibit pathogen growth.

CONCLUSION

Ecologic 641 is capable of inhibiting growth of a wide variety of pathogens isolated from infected pancreatic necrosis. The antimicrobial properties are to a large extent explained by the production of organic acids.

SIGNIFICANCE AND IMPACT OF THE STUDY

Ecologic 641 is currently being used in a Dutch nationwide double-blind, placebo-controlled, randomized multicentre trial in patients with predicted severe acute pancreatitis.

Long-term functional assessment of antegrade colonic enema for combined incontinence and constipation using a modified Marsh and Kiff technique

PURPOSE

Constipation and fecal incontinence can severely affect quality of life for patients, particularly when simultaneously present. Malone antegrade colonic enema enables periodic colonic emptying, thus preventing uncontrolled passage of feces and constipation.

METHODS

Eleven patients with fecal incontinence and severe constipation or perineal colostomy after Miles' operation underwent a modified Marsh and Kiff ileostomy for antegrade colonic enema. Before and after surgery, the patients were fully evaluated for gastrointestinal functions, including gallbladder and stomach emptying time, H(2)-breath test, colonic transit time, dynamic defecography, and anorectal manometry. The severity of incontinence and constipation was scored preoperatively and postoperatively by using the American Medical System score and Cleveland Clinic Constipation scale, respectively, whereas the quality of life was measured by the Gastrointestinal Quality of Life Index. The surgical technique involved division of the terminal ileum 10 to 15 cm from the ileocecal valve, anastomosis and intussusception of the ileum with the cecum, narrowing of the ileal conduit with a linear stapler, and a small, introflexed ileostomy with an advanced skin flap.

RESULTS

During the postoperative period, the mean American Medical System score decreased significantly from 77 to 11 (P<0.01) and the mean Cleveland Clinic Constipation score from 23 to 8.5 (P<0.01) with a significant improvement of quality of life. Antegrade colonic enema did not affect gallbladder, gastric, or orocecal transit time, which remained comparable with baseline. Colonic scintigraphy showed that antegrade colonic enema was efficient to clean the whole colon and rectum, leaving only 24 (range, 6-40) percent of the initial radioactivity after 30 minutes. Ileal manometry confirmed the presence of a high-pressure zone, preventing accidental reflux.

CONCLUSIONS

Modified Marsh and Kiff technique is a safe and effective surgical option to treat patients with combined fecal incontinence and severe constipation and those with perineal colostomy after Miles. It should be recommended as a last option before colostomy.

Management of severe acute pancreatitis: it's all about timing

PURPOSE OF REVIEW

This study provides an update on the treatment of severe acute pancreatitis (SAP) with emphasis on nutrition, infection-prophylaxis, biliary pancreatitis, surgical intervention and new randomized controlled trials.

RECENT FINDINGS

The most relevant new insights are: (i) early enteral nutrition in SAP is not only capable of reducing infectious complications but may also reduce mortality; (ii) there is increasing evidence that antibiotic-prophylaxis is not capable of preventing infectious complications in SAP; (iii) probiotic-prophylaxis is being considered as an alternative with promising experimental results; (iv) in biliary pancreatitis, early endoscopic retrograde cholangiography with sphincterotomy (within 48 h) is beneficial in case of ampullary obstruction, although it may be withheld in the event of negative endoscopic ultrasound; (v) surgical intervention for infected (peri-)pancreatic necrosis is increasingly being postponed; (vi) minimally invasive strategies are being considered as a full alternative for necrosectomy by laparotomy in infected (peri-)pancreatic necrosis; (vii) the Atlanta classification should no longer be used to describe computed tomography findings in acute pancreatitis; and (viii) only five randomized controlled trials of patients with acute pancreatitis are currently registered in the international trial registries.

SUMMARY

Timing of intervention is becoming increasingly important in SAP management.

Modification of intestinal flora with multispecies probiotics reduces bacterial translocation and improves clinical course in a rat model of acute pancreatitis

BACKGROUND

Infection of pancreatic necrosis by gut bacteria is a major cause of morbidity and mortality in patients with severe acute pancreatitis. Use of prophylactic antibiotics remains controversial. The aim of this experiment was assess if modification of intestinal flora with specifically designed multispecies probiotics reduces bacterial translocation or improves outcome in a rat model of acute pancreatitis.

METHODS

Male Sprague-Dawley rats were allocated into 3 groups: (1) controls (sham-operated, no treatment), (2) pancreatitis and placebo, and (3) pancreatitis and probiotics. Acute pancreatitis was induced by intraductal glycodeoxycholate and intravenous cerulein infusion. Daily probiotics or placebo was administered intragastrically from 5 days prior until 7 days after induction of pancreatitis. Tissue and fluid samples were collected for microbiologic and quantitative real-time PCR analysis of bacterial translocation.

RESULTS

Probiotics reduced duodenal bacterial overgrowth of potential pathogens (Log(10) colony-forming units [CFU]/g 5.0 +/- 0.7 [placebo] vs 3.5 +/- 0.3 CFU/g [probiotics], P < .05), resulting in reduced bacterial translocation to extraintestinal sites, including the pancreas (5.38 +/- 1.0 CFU/g [placebo] vs 3.1 +/- 0.5 CFU/g [probiotics], P < .05). Accordingly, health scores were better and late phase mortality was reduced: 27% (4/15, placebo) versus 0% (0/13, probiotics), respectively, P < .05.

CONCLUSIONS

This experiment supports the hypothesis that modification of intestinal flora with multispecies probiotics results in reduced bacterial translocation, morbidity, and mortality in the course of experimental acute pancreatitis.