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Updated: Jun 20, 2026
Non-Invasive Model of Neuropathogenic Escherichia coli Infection in the Neonatal Rat
Published on: October 29, 2014
Vertical and horizontal transmission of intestinal commensal bacteria in the rat model
1Laboratory of Animal Science, Kyoto Prefectural University, Shimogamo, Kyoto 606-8522, Japan.
Insights
Maternal transmission is key for developing rat intestinal microbiota. While environmental bacteria influence diversity, vertically transmitted microbes dominate pup gut ecosystems.
Area of Science:
- Microbiology
- Developmental Biology
- Gastroenterology
Background:
- The development of the intestinal microbiota is crucial for host health.
- Understanding bacterial transmission mechanisms is essential for characterizing gut ecosystem formation.
Purpose of the Study:
- To investigate the mechanisms of bacterial transmission from dams to pups.
- To compare the intestinal microbiota composition at different developmental stages in rats.
Main Methods:
- Fecal samples were collected from rat pups at suckling (18 days) and maturity (40 days), and from their dams.
- Amplified ribosomal DNA restriction analysis (ARDRA) was used to identify operational taxonomic units (OTUs).
Main Results:
- Intestinal microbiota complexity increased from suckling to maturity in pups.
- Most OTUs in mature pups were shared with their dams, comprising over 70% of the microbial community.
- A significant proportion of OTUs in pups were not shared with dams, suggesting horizontal transmission from the environment, but these constituted less than 30% of the community.
Conclusions:
- Vertically transmitted bacteria are the predominant component of the developing intestinal microbiota in rat pups.
- Horizontal transmission from environmental sources contributes to the diversity of the gut microbiota during pup growth.
Abstract:
The intestinal microbiota of 10 pups (five from dam A and five from dam B) in the suckling stage (18 days old) and at maturity (40 days old) were compared with those of their dams to assess the mechanisms of bacterial transmission during development of intestinal microbiota in the rat model. Fecal samples were subjected to amplified ribosomal DNA restriction analysis and 65 operational taxonomic units (OTUs) were identified. The intestinal microbiota of mature pups were more complex than those of the suckling stage. Most of the OTUs present in dams were detected in their pups at maturity. These common OTUs accounted for more than 70% of the clones of libraries generated from both groups of pups. In contrast, the number of OTUs in pups that were not shared by their dams was larger than the number they had in common. These bacteria were presumably transmitted horizontally from environmental sources. However, these OTUs accounted for less than 30% of the clones generated from both groups of pups. This study suggested that vertically transmitted bacteria were the predominant component of the intestinal microbiota of pups, although the diversity of intestinal microbiota during pup growth was influenced by horizontal transmission.
