Dietary bovine milk exosomes elicit changes in bacterial communities in C57BL/6 mice

Abstract

Exosomes and exosome-like vesicles participate in cell-to-cell communication in animals, plant, and bacteria. Dietary exosomes in bovine milk are bioavailable in nonbovine species, but a fraction of milk exosomes reaches the large intestine. We hypothesized that milk exosomes alter the composition of the gut microbiome in mice. C57BL/6 mice were fed AIN-93G diets, defined by their content of bovine milk exosomes and RNA cargos: exosome/RNA-depleted (ERD) versus exosome/RNA-sufficient (ERS) diets. Feeding was initiated at age 3 wk, and cecum content was collected at ages 7, 15, and 47 wk. Microbial communities were identified by 16S rRNA gene sequencing. Milk exosomes altered bacterial communities in the murine cecum. The abundance of three phyla, seven families, and 52 operational taxonomic units (OTUs) was different in the ceca from mice fed ERD and ERS ( P < 0.05). For example, at the phylum level, Tenericutes had more than threefold abundance in ERS mice at ages 15 and 47 wk compared with ERD mice ( P < 0.05). At the family level, Verrucomicrobiaceae were much less abundant in ERS mice compared with ERD mice age 47 wk ( P < 0.05). At the OTU level, four OTUs from the family of Lachnospiraceae were more than two times more abundant in ERS mice compared with ERD at age 7 and 47 wk ( P < 0.05). We conclude that exosomes in bovine milk alter microbial communities in nonbovine species, suggesting that exosomes and their cargos participate in the crosstalk between bacterial and animal kingdoms. NEW & NOTEWORTHY This is the first report that exosomes from bovine milk alter microbial communities in mice. This report suggests that the gut microbiome facilitates cell-to-cell communication by milk exosomes across species boundaries, and milk exosomes facilitate communication across animal and bacteria kingdoms.

Stochasticity constrained by deterministic effects of diet and age drive rumen microbiome assembly dynamics

“…Similar to our results, age-related change was also detected in the Verrucomicrobiaceae family in sheep, where this microbial family was persistent for over 5 months after birth 49 . Since this bacterial family was previously associated with bovine milk consumption 18,50 , it is reasonable to find it in high relative abundance early in life and to decline when there is an increase in consumption of plant-based feed (Fig. 2d).…”

Oral Administration of Bovine Milk‐Derived Extracellular Vesicles Alters the Gut Microbiota and Enhances Intestinal Immunity in Mice

“…It was reported in the recent study that the abundance of Lachnospiraceae and Ruminococaccae were significantly increased in mice rich in milk EVs diet. [ 40,41 ] It could be due to changes in the gut microbial community caused by fraction of milk EVs that escape absorption. [ 42 ] Lachnospiraceae and Ruminococcaceae were two of the most abundant families from the Order Clostridiales and had been associated with the maintenance of gut health.…”

Host- and Microbiota-Derived Extracellular Vesicles, Immune Function, and Disease Development

“…Finally, during lactation, the secretion of EVs through breastmilk are believed to influence mucosal immunity and increase the gut microbiome diversity of the offspring [68]. EVs from breastmilk are rich in mi-RNA [69,70] and hence may also influence mucosal immunity and the foetal microbiome composition.…”