NEFL and Alzheimer disease: Taken together these results suggest: (i) that microbiome-derived LPS may contribute to a progressive disruption in the read-out of the brain’s neuron-specific genetic-information; (ii) that NF-L mRNA and the expression of NF-L proteins are one important neuron-specific transcript targeted by microbiome-derived LPS; and (iii) that this may have a bearing on neuronal atrophy, disruption of the neuronal architecture and loss of synaptic organization, all of which are characteristic neuropathological features of AD-affected brain.