ABSTRACT
Viruses, bacteria, archaea, fungi, and protozoa comprise the human microbiome. In terms of the number of microbial cells and DNA, the bulk of the human microbiome is composed of bacterial species related to humans. Bacterial sequences account for over 99% of traced DNA sequencing in healthy people, as depicted in a recent study (Versalovic 2013). Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes are the primary phyla in human-associated bacterial ecosystems. Various smaller phyla are also present (Zhernakova et al. 2016). A recent investigation into the biogeography of the human microbiome found that newborns and adults harbour 30 phyla in 18 different bodily locales (Zhou et al. 2013). Studies of cultured and uncultured bacteria estimate that more than 50 bacterial phyla are connected with humans (Pace 2009). Changes in function may correspond to changes in physiology at every bodily part because a segment or habitat consists of a specific microbiome and microbiological makeup.
