Alterations in fecal short chain fatty acids (SCFAs) and branched short-chain fatty acids (BCFAs) in men with benign prostatic hyperplasia (BPH) and metabolic syndrome (MetS)

Abstract

Gut microbiome-derived short-chain fatty acids (SCFAs) emerge in the process of fermentation of polysaccharides that resist digestion (dietary fiber, resistant starch). SCFAs have a very high immunomodulatory potential and ensure local homeostasis of the intestinal epithelium, which helps maintain the intestinal barrier. We analyzed the association between stool SCFAs levels acetic acid (C 2:0), propionic acid (C 3:0), isobutyric acid (C 4:0i), butyric acid (C 4:0n), isovaleric acid (C 5:0i) valeric acid (C 5:0n), isocaproic acid (C 6:0i), and caproic acid (C 6:0n)) in aging man with benign prostatic hyperplasia (BPH) and healthy controls. The study involved 183 men (with BPH, n = 103; healthy controls, n = 80). We assessed the content of SCFAs in the stool samples of the study participants using gas chromatography. The levels of branched SCFAs (branched-chain fatty acids, BCFAs): isobutyric acid (C4:0i) (p = 0.008) and isovaleric acid (C5:0i) (p < 0.001) were significantly higher in patients with BPH than in the control group. In healthy participants isocaproic acid (C6:0i) predominated (p = 0.038). We also analyzed the relationship between stool SCFA levels and serum diagnostic parameters for MetS. We noticed a relationship between C3:0 and serum lipid parameters (mainly triglycerides) in both healthy individuals and patients with BPH with regard to MetS. Moreover we noticed relationship between C4:0i, C5:0i and C6:0i and MetS in both groups. Our research results suggest that metabolites of the intestinal microflora (SCFAs) may indicate the proper function of the intestines in aging men, and increased BCFAs levels are associated with the presence of BPH.

Structural Characterization and In Vitro Fermentation Characteristics of Enzymatically Extracted Black Mulberry Polysaccharides

“…In addition, we also found the presence of low levels of isobutyric, valeric, and isovaleric acids (Figure 6D−F). Isobutyric acid and isovaleric acid are the end products of the catabolism of branched-chain amino acids (valine, leucine, and isoleucine) 51 from proteins present in the samples by the gut microbiota. The total branched short-chain fatty acids (BCFAs, sum of isobutyric acid and isovaleric acid, Figure 6H) produced by the mulberry polysaccharide fermentation did not differ between the groups but were significantly higher than in the Con and FOS groups.…”

Gut microbiome and prostate cancer

“…Interestingly, patients with BPH have higher fecal isobutyric acid and isovaleric levels than healthy controls, and isobutyric acid, isovaleric acid, and isochronic acid were associated with the occurrence of metabolic syndrome in patients with BPH. 41 Furthermore, the Firmicutes/Bacteroidetes ratio was significantly higher in Japanese men with enlarged prostates than in men with normal-size prostates. 42 Similar mechanisms may be involved in the development of prostate cancer and BPH.…”

“…SCFAs, a major metabolite of the gut microbiota, regulate prostate cancer growth via systemic and local prostate IGF‐1. Interestingly, patients with BPH have higher fecal isobutyric acid and isovaleric levels than healthy controls, and isobutyric acid, isovaleric acid, and isochronic acid were associated with the occurrence of metabolic syndrome in patients with BPH 41 . Furthermore, the Firmicutes/Bacteroidetes ratio was significantly higher in Japanese men with enlarged prostates than in men with normal‐size prostates 42 .…”

Specialty Grand Challenge in Male Urology

“…This interestingly interplay between microbiome and gut can influence the development of MetS in patients with BPH due to the production of fatty acids. Authors also showed that the production of short chain fatty acids is accompanied by the production of harmful metabolites that contribute to the damage of the intestinal barrier and consequently to the penetration of bacterial and inflammatory factors into the blood with increasing of prostate gland inflammation and proliferation of prostate cells (7).…”