TABLE 1.

Oral microbiota related to development of Alzheimer’s disease.

No.	Studies	Outcomes	References
1	This is a cross sectional study that assess the relationship between periodontitis and cognitive impairment in older adult	• Individuals with high levels of Porphyromonas gingivalis, a periodontitis pathogen, have significantly greater odds of experiencing impairments in verbal memory and subtraction test performance	Noble et al. (2009)
2	This study investigates oral Treponema population in human brain and the association with alzheimer’s disease	• Alzheimer’s disease patients’ ganglia had treponema, and PCR could detect six out of seven types of the disease • Monoclonal antibodies against Treponema pectinovorum and Treponema socranskii were detected within the trigeminal ganglia’s badan neuron	Riviere et al. (2002)
3	This study investigates if lipopolysaccharides induce patomechanism of tau pathology	• Lipopolysaccharides from Salmonella abortus can affect pathologies associated with Alzheimer’s disease	Lee et al. (2010)
4	This study assesses serum antibody of bacteria in oral peridontal disease of participant converted to AD and control	• There was a significant increase in antibodies to Prevotella intermedia and Fusobacterium nucleatum in participants of alzheimer’s disease and mild cognitive impairment • Then, there was a significant increase in the antibodies of Treponema denticola and Porphyromonas gingivalis in Alzheimer’s disease	Stein et al. (2012)
5	This study examines the relation between alzheimer’s disease and herpes simplex virus-1 (HSV-1) and to understand the effect of HSV-1 on alzheimer’s disease progression	• Studies of proteins that interact with HSV-1 in connection with their presence in plaque and amyloid fibrillation in Alzheimer’s disease showed a very significant increase in the known binding proteins of HSV-1, in these structures	Carter (2011)