Algal oil alleviates antibiotic-induced intestinal inflammation by regulating gut microbiota and repairing intestinal barrier.

Introduction: Taking antibiotics would interfere with gut microbiota and increase the risk of opportunistic pathogen infection and inflammation.

Methods: In this study, 36 male C57BL/6 mice were divided into 4 groups ( = 9) to investigate whether two kinds of algal oil could alleviate the intestinal damage induced by CS (Ceftriaxone sodium). These algal oils were obtained from sp. cultures using Yeast extract (YE) and Rapeseed meal (RSM) as substrate, respectively. All tested mice were administrated with CS for 8 days and then the colon pathological morphology, the expression levels of inflammatory factors and the gut microbial profile were analyzed in mice supplemented with or without algal oil.

Results: The results showed that both YE and RSM algal oils markedly reduced mucosal damage and intestinal inflammatory response in CS-treated mice by inhibiting the pro-inflammatory cytokine tumor necrosis factor (TNF)-α, interleukin (IL)-6 and myeloperoxidase (MPO) activity. In addition, fluorescence immunohistochemistry showed that the tight junction protein ZO-1 was increased in mice supplemented with YE and RSM algal oil. Furthermore, YE algal oil promoted the beneficial intestinal bacteria such as and S24_7 compared with the CS group, while supplementation with RSM algal oil enriched the Robinsoniella. Spearman's correlation analysis exhibited that and were positively correlated with IL-6 but negatively correlated with IL-10.

Discussion: This study suggested that supplementation with algal oil could alleviate intestinal inflammation by regulating gut microbiota and had a protective effect on maintaining intestinal barrier against antibiotic-induced damage in mice.