The Gut Microbiota of Wild Mice

Abstract

The gut microbiota profoundly affects the biology of its host. The composition of the microbiota is dynamic and is affected by both host genetic and many environmental effects. The gut microbiota of laboratory mice has been studied extensively, which has uncovered many of the effects that the microbiota can have. This work has also shown that the environments of different research institutions can affect the mouse microbiota. There has been relatively limited study of the microbiota of wild mice, but this has shown that it typically differs from that of laboratory mice (and that maintaining wild caught mice in the laboratory can quite quickly alter the microbiota). There is also inter-individual variation in the microbiota of wild mice, with this principally explained by geographical location. In this study we have characterised the gut (both the caecum and rectum) microbiota of wild caught Mus musculus domesticus at three UK sites and have investigated how the microbiota varies depending on host location and host characteristics. We find that the microbiota of these mice are generally consistent with those described from other wild mice. The rectal and caecal microbiotas of individual mice are generally more similar to each other, than they are to the microbiota of other individuals. We found significant differences in the diversity of the microbiotas among mice from different sample sites. There were significant correlations of microbiota diversity and body weight, a measure of age, body-mass index, serum concentration of leptin, and virus, nematode and mite infection.

Fig 1. Bacterial Phyla.

A histogram showing the relative proportion of different bacterial phyla present in 39 samples from 14 mice, where the two letter prefix denotes the location from where the mouse was captured and the three digit number is the unique mouse identifier; C and R are caecal and rectal samples, respectively, all as Table 1.

Fig 2. Bacterial Families.

A histogram showing the relative proportion of different bacterial families present in 39 samples from 14 mice, where the two letter prefix denotes the location from where the mouse was captured and the three digit number is the unique mouse identifier; C and R are caecal and rectal samples, respectively, all as Table 1. For a bacterial family to be shown its abundance was ≥3% in at least one sample; bacterial families whose abundance was below this criterion are grouped in the category ‘rare’.

Fig 3. Chao 1 alpha diversity.

The Chao 1 alpha diversity values for mice at the three trapping locations (HW, WF, LU) for rectal and caecal samples where each data point represents one mouse; ⬜ female, ● male.

Fig 4. Bray-Curtis dissimilarity.

A dendrogram showing the dissimilarity among the 39 samples from 14 mice, based on the Bray-Curtis measure of dissimilarity (range 0–1), with samples colour-coded as blue HW, green WF, and red for LU; C and R are caecal and rectal samples, respectively, all as Table 1. Subscripts i, ii, and iii refer to technical replicates for the respective samples.