299/300) 2 As the world's population is aging, there is an increasing demand for research 3 regarding aging and aging-related disorders, to achieve better understanding of aging. Ideally, 4 such research would be performed with human subjects. However, due to ethical 5 considerations, animals such as rodents and monkeys are used as alternatives. Among 6 these alternative models, non-human primates are preferred because they share common 7 traits with humans. The small South American common marmoset (Callithrix jacchus) may 8 offer a number of advantages over other non-human primates in terms of its relatively small 9 size, short life span, and identical dental anatomy, compared with humans. The purpose of 10 this study was to clarify the viability of using the marmoset as a human oral disease model.
11We collected saliva samples from eight common marmosets and eight human 12 subjects. Prokaryotic DNA was extracted from the saliva samples, and 16S bacterial rRNA 13 gene sequencing was performed on each of the samples. Our results indicated that the types 14 of oral microbiomes detected among human and marmoset samples were nearly identical.
15In contrast, the oral microbiomes of our human and marmoset subjects were distinctly 16 different from those of rat and dogs, which are popular animal models. The oral microbiomes 17 of marmosets showed greater diversity than those of humans. With respect to individual 18 variation, marmosets exhibited less variation in their oral flora, compared with humans. This 19 difference in variation might be attributed to the fact that marmoset subjects were kept in a 20 controlled environment with identical lifestyles.
21The characteristics of its oral microbiota, combined with other technical advantages,
22suggest that the marmoset may provide the best animal model thus far for the study of oral 23 health. This study characterized the oral microbes of the marmoset, thereby providing 24 information to support future application of the marmoset as a model for age-related oral 25 disease.
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