Protective Effect of a Heat‐Stabilized Bacteria Probiotic Preparation (VSL#3‐HS) in a Mouse Model of Ulcerative Colitis Induced by Dextran Sulfate Sodium

Postbiotics, composed of inanimate microorganisms or their components, are gaining attention for managing intestinal discomfort, being safer than probiotics for vulnerable patients. This study investigates the effects of short-term consumption of a heat-stabilized VSL#3 formulation (VSL#3−HS) in a mouse model of dextran sulphate sodium (DSS)-induced colitis. Male C57BL/6 mice were divided into four groups: (1) Placebo (PLA); (2) VSL#3-HS (1 × 109 cells/mouse/day for 7 days); (3) DSS + PLA (2% DSS in drinking water from days 1–7, PLA from days 4–10); (4) DSS + VSL#3-HS (2% DSS from days 1–7, VSL#3-HS from days 4–10). All mice were euthanized on day 11 for tissue collection. VSL#3−HS rapidly alleviated clinical signs of the disease, including improvements in disease activity index and colon length. This effect was accompanied by a reduction in colonic pro-inflammatory mediators (IL-6, TNF-α, IL-1β) and a partial restoration of occludin gene expression in the intestine. However, no improvement was observed in MPO activity or microscopic tissue damage. The experimental findings demonstrate the efficacy of postbiotics in a murine model of UC and support further investigation into the efficacy of the heat-stabilized VSL#3-HS formulation to assess its potential applicability in human studies.