Use of one strain of Lactobacillus plantarum for the manufacture of a composition for increasing the diversity of the gastrointestinal tract by administration of said strain to an individual with a view to producing an increased diversity index compared to placebo is disclosed, as well as use of one strain of Lactobacillus plantarum for the manufacture of a composition for prophylactic treatment of a healthy individual against developing a low bacterial diversity (LBD)； of an individual having LBD against developing one or more physiologically disturbed conditions, large intestine bacterial overgrowth (LIBO) or small intestine bacterial overgrowth (SIBO)； and of an individual having LIBO or SIBO against developing one or more physiologically disturbed conditions, and a method for increasing said diversity.
