Immunomodulatory effects of Streptococcus thermophilus on U937 monocyte cell cultures

Probiotics are beneficial to the host through its contribution to the development and maintenance of a healthy immune system. Some probiotics are used in the food industry as secondary starter cultures to ferment dairy products including Streptococcus thermophilus (ST). ST bacteria were used to determine their modulatory effects on a promonocytic cell line which exhibited differential cytokine induction, in particular, IL-4 and IL-10 which are important in injury, infection and play a central role in anti-inflammatory responses. CXCL8 and GM-CSF are also activated - important for chemotaxis and recruitment of cells at sites of inflammation, and, increased CD11c, CD86, C206, CD209, MHC-1 expression. As ST are used in the dairy industry, are well tolerated when consumed and remain viable during cold storage, their consumption might be a practical approach in modulating immune responses in the host, and be beneficial to an array of diseases, including, autoimmunity and inflammatory bowel diseases.