The propionic acid and butyric acid in serum but not in feces are increased in patients with diarrhea-predominant irritable bowel syndrome

Abstract

Background & Aims ： Short-chain fatty acids (SCFAs) play a pivotal role in maintaining homeostasis in humans. It might be involved in the pathogenesis of irritable bowel syndrome (IBS). Our study aims to explore the alteration of SCFAs in patients with diarrhea-predominant IBS (IBS-D). Methods： We recruited patients with IBS-D defined by Rome Ⅳ criteria and age-and-gender matched healthy controls (HCs). A headspace solid-phase microextraction gas chromatography–mass spectrometric (HS-SPME-GC-MS) method was developed for the analysis of acetic, propionic and butyric acid in feces and serum. Results: Compared with HCs, the levels of the serum propionate (2.957 ± 0.157 vs 2.843 ± 0.098 mmol/L, P = 0.012) and butyrate (2.798 ± 0.126 vs 2.697 ± 0.077 mmol/L, P = 0.012) were significantly higher in IBS-D group. No significant differences were found among two groups with regard to the concentration of fecal acetate (4.953 ± 1.065 vs 4.774 ± 1.465 mg/g, P = 0.679), propionate (6.342 ± 1.005 vs 6.282 ± 1.077 mg/g, P = 0.868) and butyrate (2.984 ± 0.512 vs 3.071 ± 0.447 mg/g, P = 0.607). Conclusions ： Metabolites of gut microbiota, the propionic and butyric acid, are increased in patients with IBS-D in serum but not in feces. It suggests that propionic and butyric acid might be involved in the pathogenesis of IBS.

Short chain fatty acids and colon motility in a mouse model of irritable bowel syndrome

“…Therefore, as products of gut microbiota, SCFA level reflects the status of the microbiota. Moreover, in a recent study increased levels of propionate and butyrate in IBS-D in blood serum were discovered which corresponds to our data [ 42 ]. Hence, although it has been reported that fecal and mucosal microbiota are structurally diverse they are highly correlated [ 43 ], and can be used to discriminate between IBS-D subjects and healthy controls [ 44 ].…”