AUTHOR=Bednarska Olga , Biskou Olga , Israelsen Hans , Winberg Martin E. , Walter Susanna , Keita Åsa V. 

TITLE=A postbiotic fermented oat gruel may have a beneficial effect on the colonic mucosal barrier in patients with irritable bowel syndrome

JOURNAL=Frontiers in Nutrition

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.1004084

DOI=10.3389/fnut.2022.1004084

ISSN=2296-861X

ABSTRACT=<sec><title>Background</title><p>Impaired intestinal permeability and microbial dysbiosis are important pathophysiological mechanisms underlying irritable bowel syndrome (IBS). ReFerm<sup>®</sup>, also called Profermin<sup>®</sup>, is a postbiotic product of oat gruel fermented with <italic>Lactobacillus plantarum</italic> 299v. In this study, we investigated whether ReFerm<sup>®</sup> has a beneficial effect on the intestinal epithelial barrier function in patients with IBS.</p></sec><sec><title>Materials and methods</title><p>Thirty patients with moderate to severe IBS-diarrhoea (IBS-D) or IBS-mixed (IBS-M) were treated with enema containing ReFerm<sup>®</sup> or placebo. The patients underwent sigmoidoscopy with biopsies obtained from the distal colon at baseline and after 14 days of treatment with ReFerm<sup>®</sup> or placebo twice daily. The biopsies were mounted in Ussing chambers, and paracellular and transcellular permeabilities were measured for 120 min. In addition, the effects of ReFerm<sup>®</sup> or placebo on the epithelial barrier were investigated <italic>in vitro</italic> using Caco-2 cells.</p></sec><sec><title>Results</title><p>ReFerm<sup>®</sup> reduced paracellular permeability (<italic>p</italic> &lt; 0.05) and increased transepithelial resistance (TER) over time (<italic>p</italic> &lt; 0.01), whereas the placebo had no significant effect in patients. In ReFerm<sup>®</sup>-treated Caco-2 cells, paracellular and transcellular permeabilities were decreased compared to the control (<italic>p</italic> &lt; 0.05) and placebo (<italic>p</italic> &lt; 0.01). TER was increased in Caco-2 ReFerm<sup>®</sup>-treated cells, and normalised TER was increased in ReFerm<sup>®</sup>-treated Caco-2 cells compared to control (<italic>p</italic> &lt; 0.05) and placebo-treated (<italic>p</italic> &lt; 0.05) cells.</p></sec><sec><title>Conclusion</title><p>ReFerm<sup>®</sup> significantly reduced paracellular permeability and improved TER in colonic biopsies collected from patients with IBS and in a Caco-2 cell model. Our results offer new insights into the potential benefits of ReFerm<sup>®</sup> in IBS management. Further studies are needed to identify the molecular mechanisms underlying the barrier-protective properties of ReFerm<sup>®</sup>.</p></sec><sec><title>Clinical trial registration</title><p>[<ext-link ext-link-type="uri" xlink:href="https://clinicaltrials.gov/" xmlns:xlink="http://www.w3.org/1999/xlink">https://clinicaltrials.gov/</ext-link>], identifier [NCT05475314].</p></sec>