A cross-fostering investigation in rabbits has revealed that offspring gut microbiota is predominantly shaped by nongenetic maternal transmission from nursing does rather than biological mothers, with maternal influences persisting beyond weaning. The study, conducted by Shi-Yi Chen, Hancheng Gao, Junkun Zhou, Mingyan Cui, Xinyang Tian, Wenqiang Sun, Song-Jia Lai, Yinghe Qin, and Xianbo Jia, was published in Animal Microbiome. By decoupling biological parentage from post-natal maternal rearing through an experimental cross-fostering design, the researchers directly evaluated the relative contributions of host genetics and nongenetic maternal pathways in establishing and maintaining the intestinal microbial communities of developing kits.

The researchers established their investigation on the recognized role of the gut microbiota as a significant contributor to phenotypic variation in multiple production traits across livestock species. While host genetic background is known to influence microbial colonization, maternal gut microbiota can also be transferred to offspring through nongenetic routes during nursing and maternal care. If parental gut microbial characteristics can be transmitted nongenetically to progeny, livestock breeding programs could potentially improve offspring production traits through direct selection of parental individuals based on their gut microbiota profiles. However, the precise degree to which nongenetic maternal transmission governs gut microbiota composition and the duration of its persistence after weaning had remained poorly understood.

To directly test maternal transmission dynamics and resolve this knowledge gap, the research team implemented a controlled cross-fostering protocol involving 120 newborn rabbits sourced from 20 does. Newborn kits were cross-fostered among the does at birth, separating the influence of the biological mother from that of the nursing mother. The researchers then monitored and sampled the gut microbiota of all 120 kits at two distinct developmental milestones: at weaning, which occurred at 35 days of age, and subsequently at two weeks post-weaning, allowing for direct comparison of community composition across early development.

Variance component analyses conducted at weaning revealed that nursing does accounted for substantial proportions of the phenotypic variation observed across four alpha diversity metrics in the kits. Specifically, the proportion of phenotypic variation explained by the nursing doe ranged from a lower estimate of 0.218 ± 0.106 for the Evenness index to a high of 0.469 ± 0.126 for the number of observed features. These statistical estimates demonstrated that early microbial community richness and evenness metrics within individual kits were strongly determined by the foster doe nursing them.

The decisive impact of nursing does on gut microbial composition was further confirmed through community-level beta diversity evaluations. Offspring were systematically classified into four distinct comparison groups defined according to whether pairs of kits shared the same biological doe, the same nursing doe, both mothers, or neither mother. Statistical pairwise comparisons among these four groups using Kruskal-Wallis tests followed by Dunn’s post hoc comparisons revealed significant differences attributable to the nursing does. In contrast, biological does showed no statistically significant effect on the overall gut microbiota composition of kits at weaning.

Two weeks after weaning, the influence of the nursing doe remained detectable among the young rabbits, even as common litter environmental effects generally declined. At the same time, the estimated contribution of host additive genetic effects increased between weaning and two weeks post-weaning. Based on these observed patterns, the researchers concluded that offspring gut microbiota in rabbits is predominantly shaped by nongenetic maternal transmission, with maternal influences persisting beyond the suckling stage. Demonstrating the transmissibility of maternal microbiota characteristics supports the potential application of microbiome-based parental selection strategies in livestock breeding programs.

Subject of Research: Nongenetic maternal transmission and post-weaning persistence of gut microbiota in rabbits

Article Title: Evaluating nongenetic maternal transmission and post-weaning persistence of gut microbiota in cross-fostering rabbits

Article References: Chen, S.-Y., Gao, H., Zhou, J., Cui, M., Tian, X., Sun, W., Lai, S.-J., Qin, Y., & Jia, X. (2026). Evaluating nongenetic maternal transmission and post-weaning persistence of gut microbiota in cross-fostering rabbits. Animal Microbiome. https://doi.org/10.1186/s42523-026-00622-0

Image Credits: AI Generated

DOI: 10.1186/s42523-026-00622-0

Keywords: gut microbiota, maternal transmission, cross-fostering, rabbits, animal microbiome, alpha diversity, beta diversity, livestock breeding, Evaluating, nongenetic, maternal, transmission