Short-Chain Fatty Acids and the Irritable Bowel Syndrome: The Effect of Wheat Bran

Abstract

Short-chain fatty acids (SCFA) in faeces were examined in 18 patients with the irritable bowel syndrome (IBS) during treatment with wheat bran or placebo. In the placebo period, the patients could be classified in accordance with the faecal concentrations of SCFA into one group with low concentrations (mean, 40 mmol/l; range, 19-77 mmol/l; 10 patients) and another with high concentrations (mean, 168 mmol/l; range, 145-187 mmol/l; 8 patients). The concentrations of SCFA differed (P less than 0.001) in both groups from concentrations found in faeces from a reference group of nine normal individuals (mean, 114 mmol/l; range, 93-155 mmol/l). Patients with low levels of SCFA had lower (P less than 0.001) mean stool mass and longer (P less than 0.05) transit times than those with high concentrations of SCFA in faeces. Ingestion of bran, although a precursor of SCFA, did not change faecal concentrations of SCFA. Abdominal pain, distension, and rumbling were not correlated to low or high concentrations of SCFA in faeces, nor did bran improve these symptoms when compared to placebo. The level of SCFA was rather constant intraindividually and independent of the variability of the daily faecal mass. It is concluded that patients with IBS apparently have continuously abnormal concentrations of SCFA in faeces, either high or low, which are unaffected by the treatment with bran and which hypothetically may be of pathophysiologic importance.

Carbohydrate intolerance in patients with self-reported food hypersensitivity: Comparison of lactulose and glucose

“…This prompted us to measure fermentation products in the rectum. Alterations in fecal SCFA concentrations have indeed been described previously in patients with IBS [28][29][30]. However, we did not find any significant differences in rectal SCFA levels in our study, which notably were measured after complete rectal emptying.…”

“…Dialysis bags were stored overnight at +4 C and bathed in 08. 30 Rheomacrodex solution; there was no need for additional lubrication upon insertion. The dialysis bags were left for 4 h to obtain equilibrium with rectal luminal fluid [11], and dialysate was thereafter aspirated from the bags using a syringe and needle, transferred into plastic vials and stored at -80 C until analysis.…”

Daily Intake of High Dietary Fiber Slows Accelerated Colonic Transit Induced by Restrain Stress in Rats

“…Patients with IBS apparently have continuously abnormal concentrations of SCFAs in feces, either high or low. IBS patients with low levels of SCFAs have lower mean stool mass and longer transit times than those with high concentrations of SCFAs in feces [23]. The relative contribution of luminal SCFAs to the pathogenesis of IBS still remains unclear.…”

The microbiota link to irritable bowel syndrome

“…A number of studies have shown an increase in short chain fatty acids (SCFA) concentration in at least a subset of IBS stool samples. [16][17][18] Butyrate and acetate are common SCFAs produced by commensal bacteria in the human gut and are necessary for normal functioning of host-microbiota interactions. 19 The described IBS-related microbiota, (Ruminococccaceae and Clostridium cluster XIVa) are known to be enriched in producers of SCFAs.…”