In accordance with this, the levels of the cytokines interleukin-6 (IL-6) and interferon-γ (IFN-γ), which were significantly increased in emphysema mouse bronchoalveolar lavage fluid (BALF) and serum compared with the control, were significantly decreased in FMT-treated emphysema compared with the emphysema group (Fig. 1d, e). Here, IL6 is linked to pulmonary emphysema.