Furthermore, mono-colonisation with Lactobacillus bifidus was shown to be sufficient for inducing joint inflammation in a mouse model of spontaneous arthritis via TLR2- and TLR4-dependent signalling affecting the balance between Treg, Th17 and Th1 in the gut (Abdollahi-Roodsaz et al., 2008). This evidence concerns the gene TLR4 and arthritic joint disease.