High-quality DNA extraction is a crucial step in metagenomic studies.Bias by different isolation kits impairs the comparison across datasets.A trending topic is,however,the analysis of multiple metagenomes from the same patients to draw a holistic picture of microbiota associated with diseases.We thus collected bile,stool,saliva,plaque,sputum,and conjunctival swab samples and performed DNA extraction with three commercial kits.For each combination of the specimen type and DNA extraction kit,20-gigabase(Gb)metagenomic data were generated using short-read sequencing.While profiles of the specimen types showed close proximity to each other,we observed notable differences in the alpha diversity and composition of the microbiota depending on the DNA extraction kits.No kit outperformed all selected kits on every specimen.We reached consistently good results using the Qiagen QiAamp DNA Microbiome Kit.Depending on the specimen,our data indicate that over 10 Gb of sequencing data are required to achieve sufficient resolution,but DNA-based identification is superior to identification by mass spectrometry.Finally,long-read nanopore sequencing confirmed the results(correlation coefficient＞0.98).Our results thus suggest using a strategy with only one kit for studies aiming for a direct comparison of multiple microbiotas from the same patients.

Background/Aims: Patients with diverticular disease (DD) frequently have abnormal bowel movements. However, it is unknown whether the entity of these alterations is associated with the severity of DD. We aimed to assess bowel habits and their relationship with the severity of DD according to Diverticular Inflammation and Complication Assessment (DICA) classification, Combined Overview on Diverticular Assessment (CODA) score, and fecal calprotectin (FC). Methods: An international, multicenter, prospective cohort study was conducted in 43 centers. A 10-point visual analog scale (VAS) was used to assess the severity of constipation and diarrhea. The association of constipation and diarrhea with DICA classification, CODA score, and basal FC was tested using non-parametric tests. Survival methods for censored observations were applied to test the association of constipation and diarrhea with the incidence of acute diverticulitis over a 3-year follow-up. Results: Of 871 patients with DD were included in the study. Of these, 208 (23.9%) and 199 (22.9%) reported a VAS score for constipation and diarrhea at least 3 at baseline, respectively. Higher constipation and diarrhea scores were associated with increasing DICA classification, CODA score and basal FC (P< 0.001). Constipation and diarrhea scores were independently associated with an increased hazard of developing acute diverticulitis (hazard ratio [HR]constipation = 1.15 per 1-VAS point increase, 95% confidence interval [CI], 1.04–1.27; P=0.004; and HRdiarrhea =1.14; 95% CI, 1.03–1.26; P=0.014, respectively). Conclusions In newly diagnosed patients with DD, higher endoscopic and combined scores of DD severity were associated with higher scores of constipation and diarrhea at baseline. Both constipation and diarrhea were independent prognostic factors of acute diverticulitis.

Background/Aims: Patients with diverticular disease (DD) frequently have abnormal bowel movements. However, it is unknown whether the entity of these alterations is associated with the severity of DD. We aimed to assess bowel habits and their relationship with the severity of DD according to Diverticular Inflammation and Complication Assessment (DICA) classification, Combined Overview on Diverticular Assessment (CODA) score, and fecal calprotectin (FC). Methods: An international, multicenter, prospective cohort study was conducted in 43 centers. A 10-point visual analog scale (VAS) was used to assess the severity of constipation and diarrhea. The association of constipation and diarrhea with DICA classification, CODA score, and basal FC was tested using non-parametric tests. Survival methods for censored observations were applied to test the association of constipation and diarrhea with the incidence of acute diverticulitis over a 3-year follow-up. Results: Of 871 patients with DD were included in the study. Of these, 208 (23.9%) and 199 (22.9%) reported a VAS score for constipation and diarrhea at least 3 at baseline, respectively. Higher constipation and diarrhea scores were associated with increasing DICA classification, CODA score and basal FC (P< 0.001). Constipation and diarrhea scores were independently associated with an increased hazard of developing acute diverticulitis (hazard ratio [HR]constipation = 1.15 per 1-VAS point increase, 95% confidence interval [CI], 1.04–1.27; P=0.004; and HRdiarrhea =1.14; 95% CI, 1.03–1.26; P=0.014, respectively). Conclusions In newly diagnosed patients with DD, higher endoscopic and combined scores of DD severity were associated with higher scores of constipation and diarrhea at baseline. Both constipation and diarrhea were independent prognostic factors of acute diverticulitis.

Background/Aims: Patients with diverticular disease (DD) frequently have abnormal bowel movements. However, it is unknown whether the entity of these alterations is associated with the severity of DD. We aimed to assess bowel habits and their relationship with the severity of DD according to Diverticular Inflammation and Complication Assessment (DICA) classification, Combined Overview on Diverticular Assessment (CODA) score, and fecal calprotectin (FC). Methods: An international, multicenter, prospective cohort study was conducted in 43 centers. A 10-point visual analog scale (VAS) was used to assess the severity of constipation and diarrhea. The association of constipation and diarrhea with DICA classification, CODA score, and basal FC was tested using non-parametric tests. Survival methods for censored observations were applied to test the association of constipation and diarrhea with the incidence of acute diverticulitis over a 3-year follow-up. Results: Of 871 patients with DD were included in the study. Of these, 208 (23.9%) and 199 (22.9%) reported a VAS score for constipation and diarrhea at least 3 at baseline, respectively. Higher constipation and diarrhea scores were associated with increasing DICA classification, CODA score and basal FC (P< 0.001). Constipation and diarrhea scores were independently associated with an increased hazard of developing acute diverticulitis (hazard ratio [HR]constipation = 1.15 per 1-VAS point increase, 95% confidence interval [CI], 1.04–1.27; P=0.004; and HRdiarrhea =1.14; 95% CI, 1.03–1.26; P=0.014, respectively). Conclusions In newly diagnosed patients with DD, higher endoscopic and combined scores of DD severity were associated with higher scores of constipation and diarrhea at baseline. Both constipation and diarrhea were independent prognostic factors of acute diverticulitis.