TGFB1 and infection: However, synbiotics showed a smaller effect on TGF-β and MIR21 expression, and SMAD3/4 transcriptional activity compared to the cells treated with L. acidophilus alone during infection with S. typhimurium. Previous report indicates that prebiotic oligosaccharides reduce proinflammatory cytokines in intestinal Caco-2 cells via activation of PPARγ and peptidoglycan recognition protein 3 [34].