Irritable bowel syndrome (IBS) is characterized by recurrent abdominal pain and altered defecation, with a female predominance. Alterations in fecal short-chain fatty acids (SCFAs) is associated with IBS. However, little is known regarding sex-based differences in this regard.
We recruited 162 diarrhea-predominant IBS (IBS-D) patients and 66 age-matched healthy controls (HCs). Abdominal and psychological symptoms were evaluated using the IBS Severity Scoring System and Hospital Anxiety and Depression Scale (HADS). Colorectal visceral sensitivity was evaluated using barostat. Systemic inflammation was evaluated using plasma cytokine assessments. Fecal SCFAs were quantified using ultra-performance liquid chromatography-tandem mass spectrometry and fecal microbiota communities were analyzed using 16S r RNA sequencing.
There were more male patients among the consecutively enrolled IBS-D patients (70.4%,114/162). IBS-D patients had severer abdominal and psychological symptoms and higher rates of previous infectious enteritis than HCs. Notably, female patients had significantly higher HAD scores than male patients. Male patients had significantly higher plasma interleukin (IL)-12, fecal propionate, and colorectal visceral sensitivity, while no differences in these parameters were observed between female patients and female HCs. Fecal acetate, butyrate, and valerate correlated with the initial visceral sensory threshold, stressors, and plasma IL-10 and IL-12 levels. Propionate-producing Prevotella_9 genus was significantly increased in male Ipatients and positively correlated with fecal propionate.
Distinct sex differences on manifestations, fecal SCFAs and fecal microbiota were found in Chinese IBS-D patients. The changes in fecal SCFAs could indicate whether there was microbiota disorder in IBS-D patients, and assisted physicians make further individualized treatment strategy.

This article is protected by copyright. All rights reserved.