Alzheimer’s disease (AD) is an age-related neurodegenerative disease characterized by cerebral accumulation of extracellular plaques of aggregated amyloid-β (Aβ) peptide, neurofibrillary tangles composed of truncated and hyperphosphorylated Tau protein, both leading to synaptic loss, and neuronal death. To ensure cerebral homeostasis, several elimination mechanisms exist for these toxic proteins. Recently, a complex mechanism based on exchanges between different extracellular space has been identified in the brain: the glymphatic system. Our aim is to study how the brain-gut axis participates in the clearance process of toxic cerebral protein.For this purpose, we carried out longitudinal monitoring of tau protein elimination by dotblot, in the feces of APP/PS1-21 mice (a mouse model of AD). We showed an increase in the elimination of phosphorylated forms of tau in this AD model compared to control mice at early stages of the disease (1, 2, 3 months), before the appearance of cognitive alterations in these mice (6 months). Importantly, PCR and western blot experiments indicate that specific cerebral isoforms of tau are found in mice stools. Using immunofluorescence experiments, we found phosphorylated tau protein in superficial cervical lymph nodes and in immune cells present in the intestinal lymphatic system, which is highly developed.Taken together our data reveals a new clearance mechanism for toxic cerebral proteins and suggest that the brain-gut axis could participate in the cerebral homeostasis. Furthermore, our results support the potential role of fecal tau quantification as an early diagnosis tool for AD. A study in AD patients is currently underway.