Probiotic secretomes attenuate inflammation and disrupted antioxidant status induced by polychlorinated biphenyls in...

Polychlorinated biphenyls (PCBs) are persistent organic pollutants linked with intestinal inflammation and disrupted antioxidant status. Humans are exposed to PCBs primarily via PCB-contaminated foods. A comprehensive analysis of PCB modulation of intestinal inflammatory networks is lacking. Lactic acid producing bacteria (LAB) secretomes have been shown to attenuate pro-inflammatory cytokine-induced colonic cell inflammation. This study aimed to characterize markers of inflammation and antioxidant status in human intestinal T84 cells exposed to PCBs; and determine whether LAB secretomes counteract PCB-mediated inflammatory responses and disruption of antioxidant status. T84 cells were challenged with a mixture of PCB 126 (50 μΜ) and PCB 153 (50 μΜ); secretomes of Lacticaseibacillus rhamnosus R0011 (LR) or Bifidobacterium longum R0175 (BL), alone or with the PCB mixture. Cells were analyzed for superoxide dismutase (SOD) activity and expression of genes involved in xenobiotic metabolism and inflammatory responses. Cell supernatants were assessed for cytokine and chemokine profiles. PCB treatment increased the expression of genes involved in xenobiotic detoxification (CYP1A1) and free radical scavenging (MT1G). PCB treatment inhibited SOD activity, upregulated the NFκB, c-FOS, c-JUN, A20 genes involved in inflammatory responses and increased production of multiple inflammatory cytokines and chemokines involved in the IL-6 receptor complex, TNF-α receptor and interferon λ III family. The LR and BL showed antioxidant potential by restoring PCB-inhibited SOD activity, increasing ferric reducing power and cupric ion chelation ability. LR and BL attenuated the PCB-induced expression of MT1G, NFκB, c-Fos and c-Jun and decreased cytokine and chemokine production. In the presence of PCBs, the LR10 (LR 10 %), LR30 (LR 30 %) and BL30 (BL 30 %) secretomes upregulated the expression of the NFκB inhibitors, A20 and NFκBIA. This study indicates that LAB secretomes can serve as novel mediators by which probiotics protect against intestinal inflammation and disrupted antioxidant status associated with exposure to pollutants such as PCBs.