The gut microbiota is involved in various physiological functions, and disturbances in the host-microbiome have been proven to contribute to the dysfunction of gut; however, whether microbiota participates in the pathogenesis of constipation remains unclear. In this study, we extracted and analyzed microbiota in feces from constipated donors who had undergone effective therapy with fecal microbiota transplantation, transplanted microbiota into pseudo-germ-free mice, and measured gut motility. These mice presented with lower pellet frequency and water percentage, smaller pellet size, delayed gastrointestinal transit time, and weaker spontaneous contractions of colonic smooth muscle. To determine the mechanism underlying delayed gut motility, microbial metabolites were measured. Short chain fatty acids and secondary bile acids were decreased in mice receiving microbiota from constipated donors. Moreover, the compositional changes of gut microbiota in constipated patients were identified, including the operational taxonomic unit, and the species richness and α diversity were much greater than those in healthy volunteers. These findings suggest that alterations of the microbiome might affect gut motility via altered microbial-derived metabolites in the development of constipation, and the restoration of disturbed microbiota might improve the clinical phenotype. This study indicates that regulating the intestinal environment may be a novel therapy strategy for constipation.

Both bile acids and short-chain fatty acids can modulate serotonin metabolism in hosts by affecting key intermediates of the serotonin pathway. Thus, gut motility may be regulated through microbial modifications of host serotonin biosynthesis, which continues to be evaluated as a target for functional gastrointestinal disorders.

BackgroundThe ratio of C-reactive protein to albumin, as a novel inflammation-based prognostic score, is associated with outcomes in cancer and septic patients. The diagnostic accuracy of the CRP/albumin ratio has not been assessed in colorectal surgery for postoperative complications.MethodsA total of 359 patients undergoing major colorectal surgery between 2012 and 2015 were eligible for this study. Uni- and multivariate analyses were performed to identify risk factors for postoperative complications. Receiver operating characteristic curves were developed to examine the cutoff values and diagnostic accuracy of the CRP/albumin ratio and postoperative CRP levels.ResultsAmong all the patients, 139 (38.7%) were reported to have postoperative complications. The CRP/albumin ratio was an independent risk factor for complications (OR 4.413; 95% CI 2.463–7.906; P < 0.001), and the cutoff value was 2.2, which had a higher area under the curve compared to CRP on postoperative day 3 (AUC 0.779 vs 0.756). The CRP/albumin ratio also had a higher positive predictive value than CRP levels on postoperative day 3. Patients with CRP/albumin ≥2.2 suffered more postoperative complications (60.8% vs 18.6%, P < 0.001), longer postoperative stays (10 (4–71) vs 7 (3–78) days, P < 0.001), and increased surgical site infections (SSIs) (21.1% vs 4.8%, P < 0.001) than those with CRP/albumin <2.2.ConclusionsThe ratio of C-reactive protein to albumin could help to identify patients who have a high probability of postoperative complications, and the ratio has higher diagnostic accuracy than C-reactive protein alone for postoperative complications in colorectal surgery.

Synbiotic intake may efficiently restore the balance of gut microbiota and improve gastrointestinal functions. The aim of the study was to evaluate the efficacy of a synbiotic in patients with slow transit constipation. A total of 100 patients with slow transit constipation were randomized to receive either a synbiotic or placebo twice daily for 12 weeks. The primary efficacy endpoints were the clinical remission and improvement rates at weeks 4 and 12. Stool frequency and consistency, colonic transit time (CTT), evacuation and abdominal symptoms, patient assessment of constipation symptoms, gastrointestinal quality-of-life index scores, satisfaction scores, and adverse events were also monitored. The clinical remission rates reached 37.5% at week 4 and 45.8% at week 12 in the treatment group, compared to 13.3% at week 4 and 16.7% at week 12 in the placebo group (p < 0.01 for both comparisons). Over 12 weeks, 64.6% of the patients who received the synbiotic experienced clinical improvement, compared to 29.2% of the patients in the placebo group (p < 0.01). During the intervention period, patients who were treated with the synbiotic exhibited increased stool frequency, improved stool consistency, decreased CTT, and improved constipation-related symptoms. This randomized, placebo-controlled trial suggested that dietary supplementation with a synbiotic improved evacuation-parameters-associated symptoms and colonic motility in patients with slow transit constipation (STC).