The Maternal Milk Microbiome in Mammals of Different Types and Its Potential Role in the Neonatal Gut Microbiota Composition.

Yile Ge,Lu Chen,Wei Zhu,Hang Jie,Diyan Li,Qingqing Li

doi:10.3390/ani11123349

Abstract

Simple SummaryIn order to find the effects of host diet and phylogeny on maternal milk microbes and the contribution of the maternal milk microbiota to the neonatal gut microbiota, nine species of mammals of three type groups (herbivore, omnivore, and carnivore) were selected in this study. Our results showed that different types of animals and phylogeny factors may have driven the microbiota of mammalian maternal milk. Source-tracking analysis showed that the contributions of bacteria from maternal milk to the microbiota of neonates of different animals were different at day 3 after neonatal birth.Maternal milk, a main source of nutrition for neonates in early life, has attracted attention. An increasing number of studies have found that maternal milk has a high microbial diversity, as well as factors that might influence this diversity. However, there is a lack of knowledge regarding the effects of host diet and phylogeny on maternal milk microbes and the contribution of the maternal milk microbiota to the neonatal gut microbiota. Here, we analyzed the maternal milk and fecal microbiota of nine species (lion, dog, panda, human, mouse, rhesus macaque, cow, goat, and rabbit) of mammals of three type groups (herbivore, omnivore, and carnivore) using 16S rRNA amplicon sequencing. Our study provided evidence of host diet and phylogeny on the maternal milk microbiota. Moreover, functional prediction revealed that the carnivores had a significantly higher percentage of base excision repair, glycerolipid metabolism, taurine and hypotaurine metabolism, inorganic ion transport and metabolism, and nucleotide metabolism; while arginine and proline metabolism showed enrichment in the herbivore group. Source-tracking analysis showed that the contributions of bacteria from maternal milk to the microbiota of neonates of different mammals were different at day 3 after neonatal birth. Overall, our findings provided a theoretical basis for the maternal milk microbiota to affect neonatal fecal microbiota at day 3 after neonatal birth.

Highlights

The mammalian gut microbiota is believed to promote key biological activities through interactions with the digestive [1], immune [2], and nervous systems of its host [3]
After quality filtering and assembly, 5,202,990 16S rRNA gene sequences were obtained from 36 maternal milk and 35 neonatal feces bacterial DNA samples from mammals during the lactation period
When we analyzed the microbial compositions of the maternal milk and neonatal fecal samples, we found that microbial compositions of the maternal milk and neonatal fecal samples, we found that they shared many dominant bacterial genera (Figure 2B and Figure S2B)

Summary

Introduction

The mammalian gut microbiota is believed to promote key biological activities through interactions with the digestive [1], immune [2], and nervous systems of its host [3]. Bacteroidales, Clostridiales, Fibrobacteriales, and Spirochaetales, which are highly diverse cellulolytic obligate anaerobes, colonize most herbivore guts, promoting microbial fermentation to increase nutrient absorption. Maternal milk is a primary source of nutrition for neonates in early life and contains many abundant nutrients, including protein, fat, sugar, etc. An increasing number of studies have found that maternal milk microbes are crucial in guiding the spatiotemporal development of the microbiota in the neonatal gut, and aid in defense against pathogens before the immune system has matured [2,11,12,13]. Understanding the source of microbes in maternal milk and the factors that affect them provides an exciting opportunity to improve the health of neonates [21]

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