The present invention refers to micro-fragmented fat or a composition comprising micro-fragmented fat for use in the treatment of a systemic disease, preferably associated to or caused by sepsis. Moreover, the micro-fragmented fat or the composition comprising micro- fragmented fat is used for treating a systemic, inflammatory, immune, or chronic disease, said disease being intended as a consequence of septic disease. Preferably, the micro-fragmented fat is useful for treating both the acute (early) and late stages of sepsis.