This is the name given to the community of microorganisms inhabiting the length and breadth of the mammalian gastrointestinal tract. The composition of this microbial community is host specific. Each individual’s gut microbiota can undergo endogenous and exogenous alterations. It is sometimes called human flora, microflora or gut flora. These terms, however, are less used by scientists as it leads to the incorrect idea that tiny plants colonise us, while the microorganisms making up our microbiota are actually different kinds of microbes.