Date of this Version
Zhu L, Clayton JB, Suhr Van Haute MJ, Yang Q, Hassenstab HR, Mustoe AC, Knights D, Benson AK, French JA. 2020. Sex bias in gut microbiome transmission in newly paired marmosets (Callithrix jacchus). mSystems 5: e00910-19. https://doi.org/10.1128/mSystems .00910-19.
Social behavior can alter the microbiome composition via transmission among social partners, but there have been few controlled experimental studies of gut microbiome transmission among social partners in primates. We collected longitudinal fecal samples from eight unrelated male-female pairs of marmoset monkeys prior to pairing and for 8 weeks following pairing. We then sequenced 16S rRNA to characterize the changes in the gut microbiome that resulted from the pairing. Marmoset pairs had a higher similarity in gut microbiome communities after pairing than before pairing. We discovered sex differences in the degrees of change in gut microbiome communities following pairing. Speciﬁcally, the gut microbiome com-munities in males exhibited greater dissimilarity from the prepairing stage (baseline) than the gut microbiome communities in females. Conversely, females showed a gradual stabilization in the rate of the gut microbiome community turnover. Importantly, we found that the male fecal samples harbored more female-source gut microbes after pairing, especially early in pairing (paired test, P 0.05), possibly linked to sex bias in the frequencies of social behavior. From this controlled study, we re-port for the ﬁrst time that pair-living primates undergo signiﬁcant changes in gut microbiome during pairing and that females transmit more microbes to their partners than males do. The potential biases inﬂuencing which microbes are transmitted on the basis of sex and whether they are due to sex biases in other behavioral or physiological features need to be widely investigated in other nonhuman primates and humans in the future.
IMPORTANCE In this controlled study, we collected longitudinal fecal samples from 16 male and female marmoset monkeys for 2 weeks prior to and for 8 weeks after pairing in male-female dyads. We report for the first time that marmoset monkeys undergo significant changes to the gut microbiome following pairing and that these changes are sex-biased; i.e., females transmit more microbes to their social partners than males do. Marmosets exhibit pair bonding behavior such as spatial proximity, physical contact, and grooming, and sex biases in these behavioral patterns may contribute to the observed sex bias in social transmission of gut microbiomes.