Although the effect of probiotic supplementation in Alzheimer's disease on renin angiotensin system is not fully evaluated, Angiotensin (1–7)-expressing probiotic bacteria Lactobacillus paracasei (LP) raised serum serotonin and the neuroprotective biomarker 2-picolinic acid, kynurenine aminotransferase II mRNA expression, angiotensin (1–7) and reduced neuro-inflammatory gene expression in the pre-frontal cortex and serum angiotensin II levels [125, 126]. Here, AGT is linked to Alzheimer disease.