Increased Variance in Oral and Gastric Microbiome Correlates With Esophagectomy Anastomotic Leak

Microbiota profiling in esophageal diseases: Novel insights into molecular staining and clinical outcomes

Gut microbiota is recognized nowadays as one of the key players in the development of several gastro-intestinal diseases. The first studies focused mainly on healthy subjects with staining of main bacterial species via culture-based techniques. Subsequently, lots of studies tried to focus on principal esophageal disease enlarged the knowledge on esophageal microbial environment and its role in pathogenesis. Gastro Esophageal Reflux Disease (GERD), the most widespread esophageal condition, seems related to a certain degree of mucosal inflammation, via interleukin (IL) 8 potentially enhanced by bacterial components, lipopolysaccharide (LPS) above all. Gram- bacteria, producing LPS), such as Campylobacter genus, have been found associated with GERD. Barrett esophagus (BE) seems characterized by a Gram- and microaerophils-shaped microbiota. Esophageal cancer (EC) development leads to an overturn in the esophageal environment with the shift from an oral-like microbiome to a prevalently low-abundant and low-diverse Gram--shaped microbiome. Although underinvestigated, also changes in the esophageal microbiome are associated with rare chronic inflammatory or neuropathic disease pathogenesis. The paucity of knowledge about the microbiota-driven mechanisms in esophageal disease pathogenesis is mainly due to the scarce sensitivity of sequencing technology and culture methods applied so far to study commensals in the esophagus. However, the recent advances in molecular techniques, especially with the advent of non-culture-based genomic sequencing tools and the implementation of multi-omics approaches, have revolutionized the microbiome field, with promises of implementing the current knowledge, discovering more mechanisms underneath, and giving insights into the development of novel therapies aimed to re-establish the microbial equilibrium for ameliorating esophageal diseases..

Oral microbiota-host interaction: the chief culprit of alveolar bone resorption

There exists a bidirectional relationship between oral health and general well-being, with an imbalance in oral symbiotic flora posing a threat to overall human health. Disruptions in the commensal flora can lead to oral diseases, while systemic illnesses can also impact the oral cavity, resulting in the development of oral diseases and disorders. Porphyromonas gingivalis and Fusobacterium nucleatum, known as pathogenic bacteria associated with periodontitis, play a crucial role in linking periodontitis to accompanying systemic diseases. In periodontal tissues, these bacteria, along with their virulence factors, can excessively activate the host immune system through local diffusion, lymphatic circulation, and blood transmission. This immune response disruption contributes to an imbalance in osteoimmune mechanisms, alveolar bone resorption, and potential systemic inflammation. To restore local homeostasis, a deeper understanding of microbiota-host interactions and the immune network phenotype in local tissues is imperative. Defining the immune network phenotype in periodontal tissues offers a promising avenue for investigating the complex characteristics of oral plaque biofilms and exploring the potential relationship between periodontitis and associated systemic diseases. This review aims to provide an overview of the mechanisms underlying Porphyromonas gingivalis- and Fusobacterium nucleatum-induced alveolar bone resorption, as well as the immunophenotypes observed in host periodontal tissues during pathological conditions.

Role of Microbiome in the Outcomes Following Surgical Repair of Perianal Fistula: Prospective Cohort Study Design and Preliminary Results

BACKGROUND

Anal fistulae are common, predominantly cryptoglandular, and almost invariably require surgical treatment. Recurrences are common for procedures other than fistulotomy regardless of technique and adequacy of repair. Growing evidence supports the pivotal role of specific intestinal bacteria in anastomotic failures after bowel resection. Anal crypts harbor colonic microbiota suggesting that similar mechanisms to anastomotic healing might prevail after anal fistula repair and hence influence healing. This study aims at assessing the potential role of the intestinal microbiome in the clinical outcomes after surgical repair of cryptoglandular anal fistula.

METHODS

This is a pilot prospective cohort study enrolling patients with anal fistula undergoing endoanal advancement flap. For microbiome analysis, stool samples are taken via rectal swab before the procedure; additionally, a portion of the fistula is collected intraoperatively after fistulectomy. Samples from groups with treatment failure are compared to samples from patients who healed after surgical repair. Alpha and beta diversities and differential abundance of microbial taxa are determined and compared between groups with DADA2 analytical pipeline.

RESULTS

Five patients have been enrolled to date (one female, four male). At median follow-up of 6 months (2-11), one patient experienced disease recurrence at 3 months. DNA from the 5 rectal swab and tissue samples was extracted, showing increased relative abundance of Enterococcus faecalis in samples from the patient who developed a recurrent fistula but not in those without recurrence.

CONCLUSION

These very preliminary data suggest that intestinal microbiome may represent a crucial determinant of the surgical outcomes after anal fistula surgery.

Evaluation of the Oesophagogastric Cancer-Associated Microbiome: A Systematic Review and Quality Assessment

OBJECTIVE

Oesophagogastric cancer is the fifth most common cancer worldwide, with poor survival outcomes. The role of bacteria in the pathogenesis of oesophagogastric cancer remains poorly understood.

DESIGN

A systematic search identified studies assessing the oesophagogastric cancer microbiome. The primary outcome was to identify bacterial enrichment specific to oesophagogastric cancer. Secondary outcomes included appraisal of the methodology, diagnostic performance of cancer bacteria and the relationship between oral and tissue microbiome.

RESULTS

A total of 9295 articles were identified, and 87 studies were selected for analysis. Five genera were enriched in gastric cancer: Lactobacillus, Streptococcus, Prevotella, Fusobacterium and Veillonella. No clear trends were observed in oesophageal adenocarcinoma. Streptococcus, Prevotella and Fusobacterium were abundant in oesophageal squamous cell carcinoma. Functional analysis supports the role of immune cells, localised inflammation and cancer-specific pathways mediating carcinogenesis. STORMS reporting assessment identified experimental deficiencies, considering batch effects and sources of contamination prevalent in low-biomass samples.

CONCLUSIONS

Functional analysis of cancer pathways can infer tumorigenesis within the cancer-microbe-immune axis. There is evidence that study design, experimental protocols and analytical techniques could be improved to achieve more accurate and representative results. Whole-genome sequencing is recommended to identify key metabolic and functional capabilities of candidate bacteria biomarkers.

Predictive Factors for Anastomotic Leakage after Laparoscopic and Open Total Gastrectomy: A Systematic Review

The aim of this systematic review is to identify patient-related, perioperative and technical risk factors for esophago-jejunal anastomotic leakage (EJAL) in patients undergoing total gastrectomy for gastric cancer (GC). A comprehensive literature search of PubMed/MEDLINE, Embase and Scopus databases was performed. Studies providing factors predictive of EJAL by uni- and multivariate analysis or an estimate of association between EJAL and related risk factors were included. All studies were assessed for methodological quality, and a narrative synthesis of the results was performed. A total of 16 studies were included in the systematic review, with a total of 42,489 patients who underwent gastrectomy with esophago-jejunal anastomosis. Age, BMI, impaired respiratory function, prognostic nutritional index (PNI), alcohol consumption, chronic renal failure, diabetes and mixed-type histology were identified as patient-related risk factors for EJAL at multivariate analysis. Likewise, among operative factors, laparoscopic approach, anastomosis type, additional organ resection, blood loss, intraoperative time and surgeon experience were found to be predictive factors for the development of EJAL. In clinical setting, we are able to identify several risk factors for EJAL. This can improve the recognition of higher-risk patients and their outcomes.

Prior Antibiotic Exposure Is Associated With Reoperation After Elective Non-colorectal Surgery

BACKGROUND

Recent antibiotic exposure has previously been associated with poor outcomes following elective surgery. The purpose of this study is to evaluate the impact of prior recent antibiotic exposure in a multicenter cohort of Veterans Affairs patients undergoing elective non-colorectal surgery.

METHODS

This is a retrospective cohort study of the Veterans Affairs Surgical Quality Improvement Program, including elective, non-cardiovascular, non-colorectal surgery from 2013 to 2017. Outpatient antibiotic exposure within 90 days prior to surgery was identified from the Veterans Affairs outpatient pharmacy database and matched with each case. Primary outcomes included serious complication, any complication, any infection, or surgical site infection. Secondary outcomes included 30-day mortality, length of stay, and Clostridioides difficile infection.

RESULTS

Of 21,112 eligible patients, 2885 (13.7%) were exposed to antibiotics within 90 days prior to surgery with a duration of 7 (IQR: 5-10) days and prescribed 42 (IQR: 21-64) days prior to surgical intervention. Compared to non-exposed patients, exposed patients had higher unadjusted complication rates, increased length of stay, and rates of return to the operating. Exposure was independently associated with return to the operating room (OR: 1.39; 99% CI: 1.05-1.84).

CONCLUSIONS

Among Veterans, recent antibiotic exposure within 90 days of elective surgery was associated with a 39% increase in the odds of return to the operating room. Further work is needed to evaluate the effects of antibiotic exposure and dysbiosis on surgical outcomes.

Diversity and Biogeography of Human Oral Saliva Microbial Communities Revealed by the Earth Microbiome Project

The oral cavity is an important window for microbial communication between the environment and the human body. The oral microbiome plays an important role in human health. However, compared to the gut microbiome, the oral microbiome has been poorly explored. Here, we analyzed 404 datasets from human oral saliva samples published by the Earth Microbiome Project (EMP) and compared them with 815 samples from the human gut, nose/pharynx, and skin. The diversity of the human saliva microbiome varied significantly among individuals, and the community compositions were complex and diverse. The saliva microbiome showed the lowest species diversity among the four environment types. Human oral habitats shared a small core bacterial community containing only 14 operational taxonomic units (OTUs) under 5 phyla, which occupied over 75% of the sequence abundance. For the four habitats, the core taxa of the saliva microbiome had the greatest impact on saliva habitats than other habitats and were mostly unique. In addition, the saliva microbiome showed significant differences in the populations of different regions, which may be determined by the living environment and lifestyle/dietary habits. Finally, the correlation analysis showed high similarity between the saliva microbiome and the microbiomes of Aerosol (non-saline) and Surface (non-saline), i.e., two environment types closely related to human, suggesting that contact and shared environment being the driving factors of microbial transmission. Together, these findings expand our understanding of human oral diversity and biogeography.

Quantitative perfusion assessment of gastric conduit with indocyanine green dye to predict anastomotic leak after esophagectomy

Impaired gastric conduit perfusion is a risk factor for anastomotic leak after esophagectomy. The aim of this study is to evaluate the feasibility of intraoperative quantitative assessment of gastric conduit perfusion with indocyanine green fluorescence angiography as a predictor for cervical esophagogastric anastomotic leak after esophagectomy. Indocyanine green fluorescence angiography using the SPY Elite system was performed in patients undergoing a transhiatal or McKeown esophagectomy from July 2015 through December 2020. Ingress (dye uptake) and Egress (dye exit) at two anatomic landmarks (the tip of a conduit and 5 cm from the tip) were assessed. The collected data in the leak group and no leak group were compared by univariate and multivariable analyses. Of 304 patients who were evaluated, 70 patients developed anastomotic leak (23.0%). There was no significant difference in patients' demographic between the groups. Ingress Index, which represents a proportion of blood inflow, at both the tip and 5 cm of the conduit was significantly lower in the leak group (17.9 vs. 25.4% [P = 0.011] and 35.9 vs. 44.6% [P = 0.019], respectively). Ingress Time, which represents an estimated time of blood inflow, at 5 cm of the conduit was significantly higher in the leak group (69.9 vs. 57.1 seconds, P = 0.006). Multivariable analysis suggested that these three variables can be used to predict future leak. Variables of gastric conduit perfusion correlated with the incidence of cervical esophagogastric anastomotic leak. Intraoperative measurement of gastric conduit perfusion can be predictive for anastomotic leak following esophagectomy.

Associations of Changes in Intestinal Flora and Inflammatory Factors with Prognosis of Patients with Esophageal Cancer

This study aims to explore the associations of changes in intestinal flora and inflammatory factors with the prognosis of patients with esophageal cancer (EC). A total of 40 EC patients treated and 40 normal people who underwent gastroscopy and CT examination for gastrointestinal discomfort during the same period were selected as the participants of the study. The endotoxin level, colonization ability of intestinal flora, and distribution of intestinal flora (Bifidobacterium, Lactobacillus, Escherichia coli, and Enterococcus) were compared between the two groups. The levels of inflammatory factors interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), and tumor necrosis factor-α (TNF-α) were also compared between the two groups. All participants were followed up for 3 years, and the associations of survival time with colonization ability of intestinal flora and changes in hs-CRP were analyzed. Finally, the univariate and multivariate logistic regression analyses were performed for related factors affecting the survival time of EC patients. In the observation group, the endotoxin level was significantly higher (P < 0.05), the colonization ability of intestinal flora was significantly weaker (P < 0.05), the levels of Bifidobacterium and Lactobacillus were obviously lower (P < 0.05), and the levels of Escherichia coli and Enterococcus were obviously higher than those in the normal group (P < 0.05). Besides, the observation group had abnormal and evidently higher levels of IL-6, hs-CRP, and TNF-α than the normal group (P < 0.05). The survival time was positively correlated with the colonization ability of intestinal flora (P < 0.05), but negatively correlated with the changes in hs-CRP (P < 0.05). Moreover, the increased level of endotoxin, weakened colonization ability of intestinal flora, abnormal distribution of intestinal flora, and elevated levels of inflammatory factors were all related and independent risk factors affecting the survival time of EC patients. In EC patients, the endotoxin level markedly rises, the colonization ability of intestinal flora declines, and there are intestinal flora disorders and enhanced inflammatory response. With the decline in colonization ability of intestinal flora and the increase of inflammatory response, the survival time of EC patients will be shortened.

Exclusively Breastfed Infant Microbiota Develops over Time and Is Associated with Human Milk Oligosaccharide Intakes

Temporal development of maternal and infant microbiomes during early life impacts short- and long-term infant health. This study aimed to characterize bacterial dynamics within maternal faecal, human milk (HM), infant oral, and infant faecal samples during the exclusive breastfeeding period and to document associations between human milk oligosaccharide (HMO) intakes and infant oral and faecal bacterial profiles. Maternal and infant samples (n = 10) were collected at 2−5, 30, 60, 90 and 120 days postpartum and the full-length 16S ribosomal RNA (rRNA) gene was sequenced. Nineteen HMOs were quantitated using high-performance liquid chromatography. Bacterial profiles were unique to each sample type and changed significantly over time, with a large degree of intra- and inter-individual variation in all sample types. Beta diversity was stable over time within infant faecal, maternal faecal and HM samples, however, the infant oral microbiota at day 2−5 significantly differed from all other time points (all p < 0.02). HMO concentrations and intakes significantly differed over time, and HMO intakes showed differential associations with taxa observed in infant oral and faecal samples. The direct clinical relevance of this, however, is unknown. Regardless, future studies should account for intakes of HMOs when modelling the impact of HM on infant growth, as it may have implications for infant microbiota development.

Post-translational Modifications in Oral Bacteria and Their Functional Impact

Oral bacteria colonize the oral cavity, surrounding complex and variable environments. Post-translational modifications (PTMs) are an efficient biochemical mechanism across all domains of life. Oral bacteria could depend on PTMs to quickly regulate their metabolic processes in the face of external stimuli. In recent years, thanks to advances in enrichment strategies, the number and variety of PTMs that have been identified and characterized in oral bacteria have increased. PTMs, covalently modified by diverse enzymes, occur in amino acid residues of the target substrate, altering the functions of proteins involved in different biological processes. For example, Ptk1 reciprocally phosphorylates Php1 on tyrosine residues 159 and 161, required for Porphyromonas gingivalis EPS production and community development with the antecedent oral biofilm constituent Streptococcus gordonii, and in turn Php1 dephosphorylates Ptk1 and rapidly causes the conversion of Ptk1 to a state of low tyrosine phosphorylation. Protein acetylation is also widespread in oral bacteria. In the acetylome of Streptococcus mutans, 973 acetylation sites were identified in 445 proteins, accounting for 22.7% of overall proteins involving virulence factors and pathogenic processes. Other PTMs in oral bacteria include serine or threonine glycosylation in Cnm involving intracerebral hemorrhage, arginine citrullination in peptidylarginine deiminases (PADs), leading to inflammation, lysine succinylation in P. gingivalis virulence factors (gingipains, fimbriae, RagB, and PorR), and cysteine glutathionylation in thioredoxin-like protein (Tlp) in response to oxidative stress in S. mutans. Here we review oral bacterial PTMs, focusing on acetylation, phosphorylation, glycosylation, citrullination, succinylation, and glutathionylation, and corresponding modifying enzymes. We describe different PTMs in association with some examples, discussing their potential role and function in oral bacteria physiological processes and regulatory networks. Identification and characterization of PTMs not only contribute to understanding their role in oral bacterial virulence, adaption, and resistance but will open new avenues to treat oral infectious diseases.

Impact of gastrointestinal surgery upon the gut microbiome: A systematic review

BACKGROUND

There is evidence from preclinical models that the gut microbiome may impact outcomes from gastrointestinal surgery, and that surgery may alter the gut microbiome. However, the extent to which gastrointestinal surgery modulates the gut microbiome in clinical practice is currently poorly defined. This systematic review aims to evaluate the changes observed in the gut microbiome after gastrointestinal surgery.

METHODS

A systematic review and meta-analysis were conducted according to the PRISMA guidelines by screening EMBASE, MEDLINE/PubMed, Web of Science, and CENTRAL for comparative studies meeting the predetermined inclusion criteria. The primary outcome was the difference between pre and postoperative bacterial taxonomic composition and diversity metrics among patients receiving gastrointestinal surgery.

RESULTS

In total, 33 studies were identified including 6 randomized controlled trials and 27 prospective cohort studies reporting a total of 968 patients. Gastrointestinal surgery was associated with an increase in α diversity and a shift in β diversity postoperatively. Multiple bacterial taxa were identified to consistently trend toward an increase or decrease postoperatively. A difference in microbiota across geographic provenance was also observed. There was a distinct lack of studies showing correlation with clinical outcomes or performing microbiome functional analysis. Furthermore, there was a lack of standardization in sampling, analytical methodology, and reporting.

CONCLUSION

This review highlights changes in bacterial taxa associated with gastrointestinal surgery. There is a need for standardization of microbial analysis methods and reporting of results to allow interstudy comparison. Further adequately powered multicenter studies are required to better assess variation in microbial changes and its potential associations with clinical outcomes.

Esophageal microbiota composition and outcome of esophageal cancer treatment: a systematic review

BACKGROUND

The role of esophageal microbiota in esophageal cancer treatment is gaining renewed interest, largely driven by novel DNA-based microbiota analysis techniques. The aim of this systematic review is to provide an overview of current literature on the possible association between esophageal microbiota and outcome of esophageal cancer treatment, including tumor response to (neo)adjuvant chemo(radio)therapy, short-term surgery-related complications, and long-term oncological outcome.

METHODS

A systematic review of literature was performed, bibliographic databases were searched and relevant articles were selected by two independent researchers. The Newcastle-Ottawa scale was used to estimate the quality of included studies.

RESULTS

The search yielded 1303 articles, after selection and cross-referencing, five articles were included for qualitative synthesis and four studies were considered of good quality. Two articles addressed tumor response to neoadjuvant chemotherapy and described a correlation between high intratumoral Fusobacterium nucleatum levels and a poor response. One study assessed surgery-related complications, in which no direct association between esophageal microbiota and occurrence of complications was observed. Three studies described a correlation between shortened survival and high levels of intratumoral F. nucleatum, a low abundance of Proteobacteria and high abundances of Prevotella and Streptococcus species.

CONCLUSIONS

Current evidence points towards an association between esophageal microbiota and outcome of esophageal cancer treatment and justifies further research. Whether screening of the individual esophageal microbiota can be used to identify and select patients with a predisposition for adverse outcome needs to be further investigated. This could lead to the development of microbiota-based interventions to optimize esophageal microbiota composition, thereby improving outcome of patients with esophageal cancer.

The Association of Gut Microbiota and Complications in Gastrointestinal-Cancer Therapies

The therapy of gastrointestinal carcinomas includes surgery, chemo- or immunotherapy, and radiation with diverse complications such as surgical-site infection and enteritis. In recent years, the microbiome’s influence on different diseases and complications has been studied in more detail using methods such as next-generation sequencing. Due to the relatively simple collectivisation, the gut microbiome is the best-studied so far. While certain bacteria are sometimes associated with one particular complication, it is often just the loss of alpha diversity linked together. Among others, a strong influence of Fusobacterium nucleatum on the effectiveness of chemotherapies is demonstrated. External factors such as diet or specific medications can also predispose to dysbiosis and lead to complications. In addition, there are attempts to treat developed dysbiosis, such as faecal microbiota transplant or probiotics. In the future, the underlying microbiome should be investigated in more detail for a better understanding of the precipitating factors of a complication with specific therapeutic options.

Progress in the esophagogastric anastomosis and the challenges of minimally invasive thoracoscopic surgery

The esophagogastric anastomosis is most commonly performed to restore digestive tract continuity after esophagectomy for cancer. Despite a long history of clinical research and development of high-tech staplers, this procedure is still feared by most surgeons and associated with a 10% leakage rate. Among specific factors that may contribute to failure of the esophageal anastomosis are the absence of serosa layer, longitudinal orientation of muscle fibers, and ischemia of the gastric conduit. It has recently been suggested that the gut microbiome may influence the healing process of the anastomosis through the presence of collagenolytic bacterial strains, indicating that suture breakdown is not only a matter of collagen biosynthesis. The esophagogastric anastomosis can be performed either in the chest or neck, and can be completely hand-sewn, completely stapled (circular or linear stapler), or semi-mechanical (linear stapler posterior wall and hand-sewn anterior wall). Because of the lack of randomized clinical trials, no conclusive evidence is available, and the debate between the hand-sewn and the stapling technique is still ongoing even in the present era of robotic surgery. Centralization of care has improved the overall postoperative outcomes of esophagectomy, but the esophagogastric anastomosis remains the Achille’s heel of the procedure. More research and network collaboration of experts is needed to improve safety and clinical outcomes.

Effects of Sevoflurane Inhalation Anesthesia on the Intestinal Microbiome in Mice

In recent years, more and more attention has been paid to intestinal microbiome. Almost all operations will go through the anesthesia process, but it is not clear whether the intervention of anesthesia alone will affect the change in the intestinal microbiome. The purpose of this study was to verify the effect of sevoflurane inhalation anesthesia on the intestinal microbiome. The animal in the experimental group was used to provide sevoflurane inhalation anesthesia for 4 hours. The control group was not intervened. The feces of the experimental group and the control group were collected on the 1st, 3rd, 7th and 14th days after anesthesia. Sevoflurane inhalation anesthesia will cause changes in the intestinal microbiome of mice. It appears on the 1st day after anesthesia and is most obvious on the 7th day. The specific manifestation is that the abundance of microbiome and the diversity of the microbiome is reduced. At the same time, Untargeted metabonomics showed that compared with the control group, the experimental group had more increased metabolites related to the different microbiome, among which 5-methylthioadenosine was related to the central nervous system. Subsequently, the intestinal microbiome diversity of mice showed a trend of recovery on the 14th day. At the genus level, the fecal samples obtained on the 14th day after anesthesia exhibited significantly increased abundances of Bacteroides, Alloprevotella, and Akkermansia and significantly decreased abundances of Lactobacillus compared with the samples obtained on the 1st day after anesthesia. However, the abundance of differential bacteria did not recover with the changing trend of diversity. Therefore, we believe that sevoflurane inhalation anesthesia is associated with changes in the internal microbiome and metabolites, and this change may be completed through the brain-gut axis, while sevoflurane inhalation anesthesia may change the intestinal microbiome for as long as 14 days or longer.

Gastrointestinal cancers: the role of microbiota in carcinogenesis and the role of probiotics and microbiota in anti-cancer therapy efficacy

The gut epithelium is a habitat of a variety of microorganisms, including bacteria, fungi, viruses and Archaea. With the advent of sophisticated molecular techniques and bioinformatics tools, more information on the composition and thus function of gut microbiota was revealed. The gut microbiota as an integral part of the intestinal barrier has been shown to be involved in shaping the mucosal innate and adaptive immune response and to provide protection against pathogens. Consequently, a set of biochemical signals exchanged within microbes and communication between the microbiota and the host have opened a new way of thinking about cancer biology. Probiotics are living organisms which administered in adequate amounts may bring health benefits and have the potential to be an integral part of the prevention/treatment strategies in clinical approaches. Here we provide a comprehensive review of data linking gut microbiota to cancer pathogenesis and its clinical course. We focus on gastrointestinal cancers, such as gastric, colorectal, pancreatic and liver cancer.

Evaluation of effect of gestational diabetes mellitus on composition of the initial oral microbiota of neonates

Background:

Gestational diabetes mellitus (GDM) is one of the commonly occurring high-risk obstetric complications that accounts for 4%–9% of total pregnancies. The present study was an attempt to assess the effect of GDM on composition of the neonatal oral microbiota.

Materials and Methods:

In this study, oral samples from 155 full-term vaginally delivered newborns were collected with sterile swabs. Seventy-five mothers diagnosed with GDM group and 80 were nondiabetic mothers (control). The oral microbiota was evaluated and analyzed by SPSS software.

Results:

The mean gestational age in Group I was 38.1 weeks and in Group II was 39.6 weeks. Firmicutes was present in 38.1% in Group I versus 77.6% in Group II patients, Actinobacteria was seen in 15.2% in Group I and 7.4% in Group II, Bacteroidetes in 27.6% in Group I and 7.9% in Group II, Proteobacteria in 9.5% in Group I and 3.8% in Group II, and Tenericutes in 9.6% in Group I and 3.3% in Group II. There was a significant difference in major genera Prevotella, Bacteroidetes, Bifidobacterium, Corynebacterium, Ureaplasma, and Weissella in both groups (P < 0.05).

Conclusion:

There was increased bacterial microbiota in neonates born to mothers with GDM as compared to neonates born to nondiabetic mothers. Assessment of initial oral microbiota of neonates could help in assessing the early effect of GDM on neonatal oral microbial flora.

The Importance of the Microbiome in Bariatric Surgery: a Systematic Review

Bariatric surgery results in sustained weight loss, improvement of metabolic and hormonal changes, and reduction of comorbidities in obese patients. However, beneficial effects of bariatric surgery are not solely explained by restriction and malabsorption induced by surgery itself. Changes in the microbiome might play a role in this mechanism. A systematic review was performed in which 21 studies were included. The microbiome was affected by surgery and profound changes occurred in the first year of follow-up. An increase in Bacteroides and Proteobacteria and a decrease in Firmicutes were observed postoperatively in most studies. These changes were associated with weight loss. Bariatric surgery induces profound changes in the microbiome. This may be related to the beneficial effect of bariatric surgery on comorbidities associated with obesity.

Meta-Analysis of Vaginal Microbiome Data Provides New Insights Into Preterm Birth

Preterm birth (PTB) is defined as the birth of an infant before 37 weeks of gestational age. It is the leading cause of perinatal morbidity and mortality worldwide. In this study, we present a comprehensive meta-analysis of vaginal microbiome in PTB. We integrated raw longitudinal 16S rRNA vaginal microbiome data from five independent studies across 3,201 samples and were able to gain new insights into the vaginal microbiome state in women who deliver preterm in comparison to those who deliver at term. We found that women who deliver prematurely show higher within-sample variance in vaginal microbiome abundance, with the most significant difference observed during the first trimester. Modeling the data longitudinally revealed a number of microbial genera as associated with PTB, including several that were previously known and two newly identified by this meta-analysis: Olsenella and Clostridium sensu stricto. New hypotheses emerging from this integrative analysis can lead to novel diagnostics to identify women who are at higher risk for PTB and potentially inform new therapeutic interventions.

Can the microbiota predict response to systemic cancer therapy, surgical outcomes, and survival? The answer is in the gut

INTRODUCTION

The gut microbiota seems to play a key role in tumorigenesis, across various hallmarks of cancer. Recent evidence suggests its potential use as a biomarker predicting drug response and adding prognostic information, generally in the context of immuno-oncology.

AREAS COVERED

In this review, we focus on the modulating effects of gut microbiota dysbiosis on various anticancer molecules used in practice, including cytotoxic and immune-modulating agents, primarily immune-checkpoint inhibitors (ICI). Pubmed/Medline-based literature search was conducted to find potential original studies that discuss gut microbiota as a prognostic and predictive biomarker for cancer therapy. We also looked at the US ClinicalTrials.gov website to find additional studies particularly ongoing human clinical trials.

EXPERT COMMENTARY

Sequencing of stool-derived materials and tissue samples from cancer patients and animal models has shown a significant enrichment of various bacteria such as Fusobacterium nucleatum and Bacteroides fragilis were associated with resistant disease and poorer outcomes. Gut microbiota was also found to be associated with surgical outcomes and seems to play a significant role in anastomotic leak (ATL) after surgery mainly by collagen breakdown. However, this research field is just at the beginning and the current findings are not yet ready to change clinical practice.

Impact of maternal intrapartum antibiotics on the initial oral microbiome of neonates

OBJECTIVES

Prior studies have proposed that maternal intrapartum antibiotic exposure shapes the gut microbiota and, subsequently the child's health. However, the effect of maternal intrapartum antibiotic exposure and its influence on the development of the neonatal oral microbiota in early infancy has not yet been reported. The aim of this study was to compare the initial oral microbiota immediately after birth of healthy infants with and without intrapartum antibiotic exposure.

METHODS

Twenty-two newborns of the BaoAn Maternal and Child Care Hospital (Shenzhen, China) were recruited for this study, 11 born to mothers without intrapartum antibiotic exposure (NT group) and 11 to mothers with intrapartum antibiotic prophylaxis with cefamezin (AT group). Oral microbiome profiles were determined by 16S rRNA sequencing based on the V3V4 hyper-variable regions.

RESULTS

Phylum Firmicutes was most frequently detected in subjects both groups and a higher frequency was observed in the NT group than the AT group. Phyla Actinobacteria, Bacteroidetes and Proteobacteria were more abundant after intrapartum antibiotics exposure. Genus Lactobacillus belonging to Firmicutes was predominant in the neonates not exposed to antibiotics, while significantly higher percentages of genera Klebsiella, Roseburia, Propionibacterium, Faecalibacterium, Escherichia/Shigella, Corynebacterium, Bifidobacterium, and Bacteroides were noted in AT infants than NT infants. Further function analysis demonstrated that lipopolysaccharide biosynthesis and amino acid-related metabolic function was enriched in the AT group, and carbohydrate metabolism pathways were more abundant in the NT group.

CONCLUSIONS

These findings revealed distinctions in both taxa and metabolic function of oral microbiota between antibiotics-treated and unexposed groups, which indicated that maternal intrapartum antibiotic treatment is a key regulator of the initial neonatal oral microbiome.

Current evidence on the relation between gut microbiota and intestinal anastomotic leak in colorectal surgery

BACKGROUND

Anastomotic leak (AL) is a major complication in colorectal surgery. It worsens morbidity, mortality and oncological outcomes in colorectal cancer. Some evidence suggests a potential effect of the intestinal microbiome on wound healing. This review aims to provide a comprehensive review on historical and current evidence regarding the relation between the gastrointestinal microbiota and AL in colorectal surgery, and the potential microbiota-modifying effect of some perioperative commonly used measures.

DATA SOURCES

A comprehensive search was conducted in Pubmed, Medline and Embase for historical and current clinical and animal studies addressing perioperative intestinal microbiota evaluation, intestinal healing and AL.

CONCLUSIONS

Evidence on microbes' role in AL is mainly derived from animal experiments. The microbiota's composition and implications are poorly understood in surgical patients. Elaborate microbiota sequencing is required in colorectal surgery to identify potentially beneficial microbial profiles that could lead to specific perioperative microbiome-altering measures and improve surgical and oncological outcomes.

The effects of perineal disinfection on infant's oral microflora after transvaginal examination during delivery

BACKGROUND

Early life microflora is an important determinant of immune and metabolic development and may have lasting consequences. However, the mode of delivery and the effect of povidone iodine disinfection on neonatal oral microflora colonization are still unclear. The objective of the study was to understand the effects of the use of polyvidone iodine on infant's oral microflora after transvaginal examination during delivery, provided data support for the establishment of neonatal oral microflora health.

METHODS

A total of 20 cases of full-term neonatal delivered in October 2017 in Shenzhen Bao'an Maternity and Child Health Hospital through vaginal delivery. These neonates were randomly divided into two groups, the conventional disinfection group and the non-disinfection group. Simultaneously, 10 infants with elective cesarean section were taken as comparison. With Illumina MiSeq platform, 16S rRNA V3-V4 sequencing method was used to analyze bacterial DNA of oral secretions.

RESULTS

At the phylum level, compared to the non-disinfection group, higher relative abundance of Bacteroidetes and Proteobacteria, and lower proportion of Firmicutes were observed in the cesarean section group and the disinfection group. As main composition of phylum Firmicutes, genus Lactobacillus presented extremely low in the cesarean section group and the disinfection group, whereas it was the absolute dominant bacteria in the non-disinfection group. Compared with the caesarean section group, only Lactobacillus increased in majority of the non-disinfection group. There was no increase in Lactobacillus in the disinfection group, but Prevotella, Escherichia-Shigella, Staphyloccus, and Klebsiella increased significantly. Through KEGG pathway analysis, we found that there were more harmful pathways such as staphylococcus aureus infection, viral myocarditis and sporulation in the disinfection group.

CONCLUSIONS

The mode of delivery affects the infant's Lactobacillus obtained from the mother. Moreover, vulvar disinfection played an important part in the colonization of neonatal oral microbiota. And the impact of the first oral colonizers on infant health needs further follow-up investigations.

Early detection of complications: anastomotic leakage

Anastomotic leakage (AL) is one of the most critical and detrimental complications in esophageal surgery. Early diagnosis and timely therapeutic action are necessary if patients are to avoid AL-related problems. However, there is no gold standard or consensus for early diagnosis. In this review, we focus on summarizing the definition and types of AL and modalities for early diagnosis of AL after esophagectomy.

The Initial Oral Microbiota of Neonates Among Subjects With Gestational Diabetes Mellitus

Objective: The objective was to investigate the potential effect of gestational diabetes mellitus on the initial neonatal oral microbiome community structure. Methods: Oral samples were collected from 20 full-term, vaginally delivered newborns with sterile swabs. Nine of them had mothers diagnosed with gestational diabetes mellitus (GDM group), while 11 had non-diabetic mothers (NDM group). The oral microbiota was analyzed using multi-barcode 16S rRNA sequencing on Illumina MiSeq system. Results: The results showed that the birth weight, gestational age and gestational weight gain were significantly higher in NDM group. There was a significant correlation between gestational age and birth weight. Neonatal oral microbiome was composed of five dominant phyla from Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria, and Tenericutes. Compared to NDM group, a higher alpha diversity and reduction of phylum Firmicutes were observed in GDM group. Genus Lactobacillus dominated in NDM group, while Alistipes, Streptococcus, and Faecalibacterium were overabundant in GDM group. Additionally, carbohydrate metabolism increased in NDM group, whereas amino acid metabolism, vitamin metabolism and lipopolysaccharide biosynthesis were more abundant in GDM group. Conclusions: This study showed a distinct oral microbiota profile in neonates born to mothers with GDM, which indicated that maternal diabetes status played an important role in neonatal initial oral microbiota.

Oral microbiomes: more and more importance in oral cavity and whole body

Microbes appear in every corner of human life, and microbes affect every aspect of human life. The human oral cavity contains a number of different habitats. Synergy and interaction of variable oral microorganisms help human body against invasion of undesirable stimulation outside. However, imbalance of microbial flora contributes to oral diseases and systemic diseases. Oral microbiomes play an important role in the human microbial community and human health. The use of recently developed molecular methods has greatly expanded our knowledge of the composition and function of the oral microbiome in health and disease. Studies in oral microbiomes and their interactions with microbiomes in variable body sites and variable health condition are critical in our cognition of our body and how to make effect on human health improvement.