Composition and stability of the vervet monkey milk microbiome

Abstract

The human milk microbiome is vertically transmitted to offspring during the postnatal period and has emerged as a critical driver of infant immune and metabolic development. Despite this importance in humans, the milk microbiome of nonhuman primates remains largely unexplored. This dearth of comparative work precludes our ability to understand how species-specific differences in the milk microbiome may differentially drive maternal effects and limits how translational models can be used to understand the role of vertically transmitted milk microbes in human development.Here, we present the first culture-independent data on the milk microbiome of a nonhuman primate. We collected milk and matched fecal microbiome samples at early and late lactation from a cohort of captive lactating vervet monkeys (N = 15).We found that, similar to humans, the vervet monkey milk microbiome comprises a shared community of taxa that are universally present across individuals. However, unlike in humans, this shared community is dominated by the genera Lactobacillus, Bacteroides, and Prevotella. We also found that, in contrast to previous culturedependent studies in humans, the vervet milk microbiome exhibits greater alphadiversity than the gut microbiome across lactation. Finally, we did not find support for the translocation of microbes from the gut to the mammary gland within females (i.e.,

Early life gut microbiome dynamics mediate maternal effects on infant growth in vervet monkeys

“…The copyright holder for this preprint (which this version posted May 13, 2021. ; https://doi.org/10.1101/2021.05.11.443657 doi: bioRxiv preprint contributed fecal samples and somatometric data at T1 only, and the T1 milk sample from the female with unilateral milk production was excluded from this study. Milk collection followed previously published protocols for the collection of milk from cercopithecine monkeys [17,41]. Both mammary glands were fully evacuated via manual expression into a single sample tube.…”

“…Similar to the lactational transfer of maternal hormones and immune factors, the transfer of bacteria from milk to the infant gut reflects a direct postnatal connection between maternal and infant physiologies. Milk harbors an ephemeral yet diverse community of microbiota [38][39][40][41][42] that contributes substantially to the colonization of the infant gut microbiome across postnatal life [43]. In humans, some microbial taxa are exclusively shared between milk and infant gut communities [44,45], evidence of a unique milk-infant gut transmission pathway independent of other maternal reservoirs.…”

“…Vervet monkeys (Chlorocebus aethiops sabaeus) are a valuable model system for investigating the relationship between parity, the infant gut microbiome, and early growth, particularly with respect to the role of the milk microbiome. Similar to humans, vervets possess a milk microbiome that is highly diverse and abundant in growthassociated taxa such as Bacteroides fragilis [41]. Variation in Bacteroides colonization in human infants is not explained by exposure to the vaginal microbiome [47], suggesting that the transfer of B. fragilis to infants may occur primarily via milk or the maternal gut.…”

Developmental responses to early‐life adversity: Evolutionary and mechanistic perspectives

“…Further, the trajectory of the developing gut microbiome is heavily influenced by maternal vertical transmission. Maternal skin, fecal, and vaginal microbes are some of the first to colonize the infant's gut at birth, followed by milk‐origin microbes and bacteria‐modifying factors (e.g., probiotic oligosaccharides) that further shape the infant's gut microbiome during lactation …”

“…Maternal skin, fecal, and vaginal microbes are some of the first to colonize the infant's gut at birth, followed by milk-origin microbes and bacteriamodifying factors (e.g., probiotic oligosaccharides) that further shape the infant's gut microbiome during lactation. 128,[130][131][132] These earliest periods of bacterial colonization are highly sensitive to disturbance. Clinical evidence from human infants demonstrates that antibiotics, Caesarean section (C-section) delivery, 133 and formula feeding all disrupt the infant gut microbiome, 128,134 with reductions in microbial diversity and changes in composition that may persist into adulthood.…”