Analysis of difference in oral bacteria flora in saliva among elderly people in longevity zone of Guangxi

Objective To investigate the bacterial species, characteristics and differences of oral bacteria flora of saliva in the longevous elderly between in Bama county and in Debao county in Guangxi, in order to explore the relationship between longevity and oral salivary bacteria flora in the elderly. Methods The saliva was taken from the longevous elderly in Bama county(BM group)and people aged over 60 years in Debao county(BS group)separately, and the total DNA was extracted.The 16S rDNA-V4 region was amplified by PCR and analyzed by sequencing.The main species and diversity of bacterial colonies were recorded for difference analysis. Results A total of 14 saliva samples were collected from 7 cases in BM group and 7 cases in BS group.A total of 369 OTUs were generated by cluster analysis of 14 samples.At the genus level, the dominant salivary bacteria flora were Ctinomyces, Capnocytophaga, Chryseobacterium, Fusobacterium, Haemophilus, Lactobacillus, Leptotrichia, Neisseria, Porphyromonas, Prevotella, Rothia, Streptococcus, Veillonella in both BM group and BS group.The OTU PCA analysis showed that some evidence for indeterminate differences was found, but statistically significant differences did not exist in the dominant components of oral flora between the two groups(P>0.05). Also, the same tendency toward the diversity(P>0.05)was presented.Similarly, the species annotation analysis and the heat map showed that there were no significant differences(P>0.05)in oral salivary flora composition between the two groups.Lactobacillu was always the prevailing flora in the Phylume, Class, Order, Family and Genus, but the abundance ratio was different between the two groups as following: Lactobacillus abundance in salivary bacteria flora was higher in BM Group than in the BS group, while Mycoplasma abundance was lower in BM Group than in the BS group(P<0.05). Conclusions The dominant salivary bacteria flora is Lactobacillus in both BM and BS group, while, the abundance of Lactobacillus is higher in the BM group than in the BS group, which indicates that the longevity of population in Bama county may be related to Lactobacillus. Key words: Longevity; Saliva; DNA, bacterial