Effects of moderate beer consumption on immunity and the gut microbiome in immunosuppressed mice

Beer contains a variety of bioactive ingredients and trace elements that can regulate bodily functions, and moderate consumption of beer can enhance immune responses. This study aimed to investigate the potential benefits of moderate consumption of alcoholic or non-alcoholic beer on the gut microbiome, immunity, and intestinal barrier function in immunosuppressed BALB/c mice induced by cyclophosphamide (CTX). Model mice with CTX-induced immunosuppression were administered alcoholic or non-alcoholic beer or galacto-oligosaccharides (GOS) for 28 consecutive days. The GOS and beer intervention groups all showed alleviation of spleen tissue damage, an increased immune organ index, decreased gut inflammation, and reduced serum concentrations of D-lactic acid, lipopolysaccharide, and tumor necrosis factor α. High-throughput 16S rRNA gene sequencing revealed higher relative abundances of Firmicutes and Actinobacteriota, and lower relative abundances of Bacteroidota, Lactobacillus, and Bifidobacterium, in CTX mice than in normal control mice. In addition, Firmicutes showed lower abundance, while Desulfobacterota showed higher abundance in CTX mice with non-alcoholic beer intake than without it. Spearman correlation analysis indicated that Bacteroidota was negatively correlated with propionic acid and butyric acid, while Desulfobacterota was positively correlated with butyric acid. Proteobacteria was negatively correlated with acetic acid, propionic acid, isobutyric acid, and valeric acid. Helicobacter was positively correlated with valeric acid. In conclusion, this is one of the first studies to examine the modulatory effects of moderate alcohol consumption in immunocompromised mice. Our findings indicate that beer consumption can alter the gut microbiome and metabolites, enhancing immunity in mice.