NOS2 and Alzheimer disease: One previous study employing 3×Tg-AD mice revealed that chronic supplementation with SLAB51, a multi-strain probiotic formulation, can augment the cerebral expression of HIF-1α, possibly by reducing the level of PHD2 critical for HIF-1α degradation; SLAB51 also decreases the expression of inducible nitric oxide synthase (iNOS) in the brain, with a reduction in NO levels in the plasma of AD mice [162].