Lactobacillus fermentum (MTCC-5898) based fermented whey renders prophylactic action against colitis by strengthening the gut barrier function and maintaining immune homeostasis

Nutritional intervention using probiotic fermented dairy product has emerged as a promising therapeutic strategy to curb inflammatory bowel diseases. The present study was aimed to investigate the prophylactic capability of probiotic Lactobacillus fermentum (LF:MTCC-5898) fermented whey on impaired barrier function in DSS induced mice. Probiotic fermented whey (PFW) consumption improved the symptoms of colitis-associated with intestinal inflammation by significantly (p < 0.01) diminishing the percent loss in body weight, disease activity index and spleen index with improvement in colon length and weight besides hematological and histopathological score. Likewise, pre-treatment with PFW improved the barrier integrity (p < 0.01) in contrast to leaky condition induced by DSS administration characterized with increased permeability of FITC-dextran (451 ± 225.1) across epithelium. PFW consumption also provided the gut immune protection that occurred via significant increase (p < 0.05) in TLR-2 expression and stimulated T-regulatory response by producing TGF-β (p < 0.01), to potently suppress (p < 0.01) induced inflammatory response markers (TNF-α, IL-4 and C-reactive protein). Consistently, in preventive way, PFW intake significantly enhanced (p < 0.05) immunoglobulin (sIgA) secretion and concomitantly restored the Occludin, ZO-1 (p < 0.01), Claudin -1(p < 0.05) transcriptional expression as compared to colitis mice. Additionally, immune-fluorescence further established the presence of intact actin cytoskeleton and tight junction proteins (claudin-1, occludin and ZO-1) after PFW consumption. Thus, PFW rectified the impaired and leaky barrier junctions not only through modulation of transcriptional expression of tight junction genes but also with reduced secretion of inflammatory mediators and helped in ameliorating the colitis. Hence, probiotic fermented whey could be used as potential prophylactic functional food in the prevention of gut ailments.