Anti‐inflammatory effect of Bifidobacterium animalis subsp. lactis A6 on DSS‐induced colitis in mice

Aims This study aimed to investigate the protective effect of Bifidobacterium animalis subsp. lactis A6 on dextran sodium sulphate (DSS)‐induced colitis in C57BL/6J mice. Methods and Results Mice were randomly divided into three groups (n = 8 per group). Each group was administered with PBS (Control and DSS group) or B. lactis A6 with a dosage of ~4.0 × 109 CFU day−1 (DSS + A6 group) for 21 consecutive days. The DSS and DSS + A6 group mice were ad libitum drinking 2.5% DSS water during day 15–21, while the Control group mice were given normal water. The administration of B. lactis A6 significantly inhibited DSS‐induced bodyweight loss and colon shortening (p 0.05). The intestinal barrier integrity was improved by reducing colonic damage, recovering mucus layer loss and enhancing tight junction expression including ZO‐1, occludin and claudin‐1. In addition, B. lactis A6 attenuated the oxidative stress by decreasing MDA and increasing SOD and GSH levels in colon tissues. Moreover, B. lactis A6 suppressed DSS‐induced inflammatory responses via downregulating TNF‐α, IL‐1β and IL‐6 levels and upregulating IL‐10 level in colon tissues. Conclusion B. lactis A6 effectively alleviated DSS‐induced colitis by maintaining intestinal barrier integrity, reducing oxidative stress and inhibiting inflammatory responses. Significance and Impact of the Study This study suggests that B. lactis A6 could act as a candidate probiotic for UC treatment.