Fermented black barley ameliorates lung injury induced by cooking oil fumes via antioxidant activity and regulation of the intestinal microbiome in mice

To investigate the effect of fermented black barley on cooking oil fume (COF)-induced lung injury, male ICR mice were randomized into five groups: normal control (NC), fermented black barley treatment (NF), COF exposure (O), COF + fermented black barley treatment (OF) and COF +  Lactobacillus treatment (OL). The exposure of mice to COF was performed for 5 min per day and 4 days per week for a total of 9 weeks, and the mice in the OF, NF and OL groups were administered fermented black barley or Lactobacillus continuously for 9 weeks (1 mL/100 g). Our results showed that the gamma-aminobutyric acid (GABA), total phenolic, and flavonoid contents significantly increased after fermentation ( P  < 0.01). In addition, fermented black barley significantly increased SOD activity in the lung tissue, decreased the wet pulmonary coefficient, inhibited the reduction of microbial diversity and richness, and upregulated genes involved in cilium assembly and the cilium axoneme. These findings support the notion that fermented black barley can ameliorate COF-induced lung injury in mice.