Distinct differences in gut microbial composition and functional potential from lean to morbidly obese subjects

INTRODUCTION

The gut microbiome may contribute to the development of obesity. So far, the extent of microbiome variation in people with obesity has not been determined in large cohorts and for a wide range of body mass index (BMI). Here, we aimed to investigate whether the faecal microbial metagenome can explain the variance in several clinical phenotypes associated with morbid obesity.

METHODS

Caucasian subjects were recruited at our hospital. Blood pressure and anthropometric measurements were taken. Dietary intake was determined using questionnaires. Shotgun metagenomic sequencing was performed on faecal samples from 177 subjects.

RESULTS

Subjects without obesity (n = 82, BMI 24.7 ± 2.9 kg m^-2 ) and subjects with obesity (n = 95, BMI 38.6 ± 5.1 kg m^-2 ) could be clearly distinguished based on microbial composition and microbial metabolic pathways. A total number of 52 bacterial species differed significantly in people with and without obesity. Independent of dietary intake, we found that microbial pathways involved in biosynthesis of amino acids were enriched in subjects with obesity, whereas pathways involved in the degradation of amino acids were depleted. Machine learning models showed that more than half of the variance in body fat composition followed by BMI could be explained by the gut microbiome, composition and microbial metabolic pathways, compared with 6% of variation explained in triglycerides and 9% in HDL.

CONCLUSION

Based on the faecal microbiota composition, we were able to separate subjects with and without obesity. In addition, we found strong associations between gut microbial amino acid metabolism and specific microbial species in relation to clinical features of obesity.

Volume of surgery for benign colorectal polyps in the last 11 years

BACKGROUND AND AIMS

Traditionally large, complex colorectal polyps were managed by surgical resection (SR), and in recent years endoscopic resection (ER) has progressed significantly. However, to what extent ER has replaced SR remains largely unknown. We performed a multicenter retrospective cohort study to assess the volume and volume changes of SR for benign colorectal polyps over the past decade.

METHODS

Patients who underwent SR for a benign colorectal polyp in the Netherlands between 2005 and 2015 were selected from the prospective nationwide Dutch Pathology Registry (PALGA database). Clinical characteristics were obtained from the charts of patients who underwent SR in the province of Noord-Holland.

RESULTS

A total of 5937 patients were treated with SR for a colorectal polyp and the absolute (454-739 per year) and relative volumes (0.20%-0.37% per colonoscopy per year) of SR remained stable. In the province of Noord-Holland, 928 patients (15.6%) underwent SR. In these patients, submucosal lifting and ER were attempted in 19.9% (n = 175) and 15.0% (n = 134). After 2010, patients were more likely to undergo lifting (27.7% vs 11.4%, P < .001) and ER attempts (18.8% vs 10.9%, P = .001) before definitive SR. Twenty-two patients (2.4%) had been referred to another endoscopy clinic.

CONCLUSIONS

SR for large, complex colorectal polyps is still frequently performed and has remained stable. A small percentage of patients underwent ER attempts before SR, and referral for an additional ER attempt only occurred in a minority of cases. To increase ER attempts, implementation of a regional multidisciplinary referral network should be considered.

A multi-centred randomised trial of radical surgery versus adjuvant chemoradiotherapy after local excision for early rectal cancer

Background

Rectal cancer surgery is accompanied with high morbidity and poor long term functional outcome. Screening programs have shown a shift towards more early staged cancers. Patients with early rectal cancer can potentially benefit significantly from rectal preserving therapy. For the earliest stage cancers, local excision is sufficient when the risk of lymph node disease and subsequent recurrence is below 5 %. However, the majority of early cancers are associated with an intermediate risk of lymph node involvement (5–20 %) suggesting that local excision alone is not sufficient, while completion radical surgery, which is currently standard of care, could be a substantial overtreatment for this group of patients.

Methods/Study design

In this multicentre randomised trial, patients with an intermediate risk T1-2 rectal cancer, that has been locally excised using an endoluminal technique, will be randomized between adjuvant chemo-radiotherapylimited to the mesorectum and standard completion total mesorectal excision (TME). To strictly monitor the risk of locoregional recurrence in the experimental arm and enable early salvage surgery, there will be additional follow up with frequent MRI and endoscopy. The primary outcome of the study is three-year local recurrence rate. Secondary outcomes are morbidity, disease free and overall survival, stoma rate, functional outcomes, health related quality of life and costs. The design is a non inferiority study with a total sample size of 302 patients.

Discussion

The results of the TESAR trial will potentially demonstrate that adjuvant chemoradiotherapy is an oncological safe treatment option in patients who are confronted with the difficult clinical dilemma of a radically removed intermediate risk early rectal cancer by polypectomy or transanal surgery that is conventionally treated with subsequent radical surgery. Preserving the rectum using adjuvant radiotherapy is expected to significantly improve morbidity, function and quality of life if compared to completion TME surgery.

Trial registration

NCT02371304, registration date: February 2015

The use of Oxaliplatin or Mitomycin C in HIPEC treatment for peritoneal carcinomatosis from colorectal cancer: a comparative study

BACKGROUND

Oxaliplatin and Mitomycin C (MMC) are both suitable as intraperitoneal chemotherapy agents in HIPEC for peritoneal carcinomatosis (PC) of colorectal cancer (CRC).

METHODS

Patient cohorts from two different HIPEC-centers underwent cytoreductive surgery and HIPEC with Oxaliplatin (39 patients) and MMC (56 patients), respectively. They were compared for toxicity and survival data. The extent of PC was assessed using the Dutch 7-region count.

RESULTS

The median 7-region count was 4 [range 0-7] for Oxaliplatin-patients versus 2.5 [range 1-6] for MMC-patients (P = 0.004). Median intra-operative blood loss was 650 ml [0-6,000 ml] in Oxaliplatin-patients versus 1,230 ml [range 0-5,300 ml] in MMC-patients (P < 0.001). Only MMC-patients developed neutropenia/leucopenia (26.8%, P < 0.001). After statistical correction for the extent of PC, the overall postoperative complication rate was significantly higher in MMC-patients (OR = 2.68 (95% CI: 1.04-6.91), P = 0.04), with a comparable intra-abdominal complication (IAC) rate (OR = 0.78 (95% CI: 0.30-2.03), P = 0.61), but a tendency towards more extra-abdominal complications (EAC) in MMC-patients (OR = 2.23 (95% CI: 0.91-5.43), P = 0.079). Median follow-up was significantly shorter for Oxaliplatin-patients (2.8 years) than for MMC-patients (5.1 years). Median RFS was 12.2 months [IQR: 7.2-undefined] in the Oxaliplatin-group and 13.8 months [IQR: 7.0-25.8] in the MMC-group (P = 0.87). Median OS is 37.1 months [IQR: 22.4-52.8] for Oxaliplatin-patients and 26.5 months [IQR: 16.9-64.8] for MMC-patients (P = 0.45). Logistic regression analysis (corrected for extent of PC) shows RFS (HR = 1.24 (95% CI: 0.75-2.05), P = 0.39) and OS (HR = 1.37 (95% CI: 0.74-2.54), P = 0.32) are not significantly different.

CONCLUSIONS

No clear benefit in RFS and OS for HIPEC with Oxaliplatin or MMC could be demonstrated in patients with PC from CRC.

Enzyme degradation during drying

During drying of food materials a multitude of chemical reactions and/or physical changes may occur. In this article attention is focused on one of these, namely, inactivation of enzymes during drying. The prediction of enzyme retention during drying is of interest to the pharmaceutical industry for the production of dry enzyme preparations and to the food processing industry in drying operations of food materials containing enzymes. In this article calculated enzyme retentions are presented for different drying histories and shapes of drying particles. In the numerical calculations it is assumed that enzyme degradation kinetics are first-order reactions, of which reaction constants are known as a function of temperature and water concentration in the drying material. From the calculations, conclusions can be drawn about conditions favorable for high enzyme retentions, or for high enzyme degradations.

Cardiac and hemodynamic effects of hemodialysis and ultrafiltration

Imbalance between cardiac oxygen supply and demand may trigger cardiac events in already vulnerable hemodialysis (HD) patients. We studied the effect of ultrafiltration (UF) and HD in nine chronic HD patients by continuously measuring blood volume (BV; by Critline), blood pressure (BP; by Portapres), and changes in hemodynamics (Modelflow) during isolated UF (iUF) of 500 mL in 30 minutes and subsequent HD combined with UF (HD + UF). Aortic pressure was reconstructed from finger pressure. Changes in cardiac oxygen supply were assessed by calculating the area under the aortic pressure curve during diastole (diastolic pressure time index [DPTI]). Changes in cardiac oxygen demand were assessed by calculating systolic pressure time index (SPTI). BV decreased 4.0% +/- 1.8% during UF and 7.3% +/- 3.3% during HD + UF (both P < 0.01). Systolic BP did not change; diastolic and mean BP increased 11 +/- 7.4 and 11 +/- 8.4 mm Hg during iUF, respectively (both P < 0.01), and stabilized during HD + UF. Overall pulse pressure decreased 19 +/- 11.1 mm Hg (P < 0.01). Heart rate increased 13 +/- 11 beats/min (P < 0.01) and systemic vascular resistance increased 59% +/- 51% (P < 0. 01), whereas stroke volume and cardiac output (CO) decreased by 40% +/- 17% and 30% +/- 13%, respectively (both P < 0.01). Both cardiac oxygen supply (DPTI) and demand (SPTI) increased during iUF, and both decreased during HD + UF. By the end of the procedure, DPTI/SPTI ratio had increased 9% +/- 8% (P < 0.05). Changes in CO correlated closely to changes in BV. Despite large changes in hemodynamics during uncomplicated UF and HD, the balance between cardiac oxygen supply and demand (DPTI/SPTI ratio) did not decrease, but improved slightly.