Several studies have shown that oral intake of low doses of native chicken collagen have positive effects on symptoms such as joint swelling and joint paint in patients with RA, strongly indicating a dampening of the chronic inflammation present in these patients (Barnett, Combitchi and Trentham, 1996; Barnett et al., 1998). The mechanism of action is thought to be by oral tolerance. Oral tolerance is initiated, when an antigen, in this case native chicken collagen type II, passes through the gut and the gut-associated-lymphoid-tissue induces systemic tolerance towards that antigen through the activation of regulatory T-cells (Weiner and Wu, 2011). Additionally, a recent study indicates that the joint pain of OA can be relieved by oral intake of native chicken collagen type II (Bakilan et al., 2016).