Lactobacillus is most commonly taken by mouth to treat and prevent diarrhoea, including infectious diarrhoea and diarrhoea linked with using antibiotics. Some people also take lactobacillus by mouth for general digestion problems, irritable bowel syndrome (IBS), colic in babies, inflammatory bowel disease (IBD). Lactobacillus can help us break down food, absorb nutrients, and fight off “unfriendly” organisms that might cause diseases such as diarrhoea.Lactobacillus is a valuable weapon in our gut armoury. They are also called L. acidophilus. They make lactic acid by breaking down carbohydrates.