Table 4.

Subtypes of T-cells, role played, health impact due to overexpression of the T cells and gut microbial taxa influencing T cell differentiation

Subtype of T cell	Role played	Overexpression of T cells	Gut microbial taxa influencing T cell differentiation
Th1	Host defence against intracellular microbial infection	Autoimmune disease	Bacillus fragilis
Th2	Elimination of infection by parasites	Allergen specific IgE response	Roseburia intestinalis
Th 17	Produces IL-17; a crucial cytokine involved in limiting invasion and dissemination of pathogens, such as Salmonella typhimurium	Autoimmune disease	Segmented filamentous bacteria (SFB)
T reg	Immune tolerance; promotes class switching to IgA in presence of specific antigen	Autoimmune disorder	Clostridial clusters IV. XIVa