The present invention relates to novel isolated strains of Bifidobacterium adolescentis which are capable of i) increasing the trans-epithelial electrical resistance (TER) of a Caco-2 cell monolayer after 10 h treatment to more than 120% of TER at treatment start, ii) inducing secretion of >200 pg / ml of IL-10, and / or iii) inducing an IL-10:IL-12 ratio >1 when co-incubated with human PBMC derived dendritic cells. The strains may have one, two or all three of these capabilities. The present invention relates to the use of these novel strains for the in prevention, alleviation of symptoms, and treatment of diseases or conditions with an underlying impaired intestinal barrier function and pro-inflammatory activation of the mucosa. More specifically, the present invention relates to se of an isolated strain according to the invention for the prevention, alleviation of symptoms, or treatment of intestinal inflammatory conditions such as IBD and IBS, liver diseases such as NAFLD, NASH, cirrhosis, and alcohol-related liver disease, metabolic disorders such as metabolic syndrome, insulin resistance, type 2 diabetes, obesity, cardiovascular atherosclerosis, autoimmune diseases, such as celiac disease, type 1 diabetes, multiple sclerosis and rheumatoid arthritis, and mental conditions such as major depressive disorders, a mood disorder, a cognitive chronic fatigue syndrome, and anxiety.