**3. Human microbiome project**

The major goal of the human microbiome project is to define the number, diversity and functionality of genes found in all bacteria that live in various parts of the human body on a permanent basis and analyze its role in human health and disease. The gut microbiota expresses around 3.3 million bacterial genes, compared to only 20,000 genes in the human genome. Studies show that manipulating non-pathogenic bacterial strains in the host can help the immune system recover from disorders caused by pathogenic bacteria. An ever-growing number of studies have demonstrated that changes in the composition of our microbiomes correlate with numerous disease states, raising the possibility that manipulation of these communities could be used to treat disease. The microbiome of a person can affect their susceptibility to infectious diseases and contribute to gastrointestinal chronic disorders including Crohn's disease and irritable bowel syndrome. A person's response to a pharmacological therapy is determined by a group of microorganisms. The mother's microbiome may have an impact on her children's health.

Researchers researching the human microbiome are discovering previously unknown organisms and genes all around the world. Various combinations of microbial species have been related to certain human health issues in genetic studies that quantify the relative abundance of different species in the human microbiome. A thorough understanding of the diversity of microbes in the human microbiome could lead to new therapeutics, such as producing more "good" bacteria to cure a bacterial infection caused by "bad" bacteria. The HMP is a road plan for understanding and describing the role of the microbiome in health, nutrition, immunology, and disease.
