Figure 2. Inefficient inter-generational transfer of taxa driven to low abundance by low dietary MACs.

a, Schematic of multigeneration mouse experiment. Second (n=6), third (n=6), and fourth generation mice (n=6) were weaned onto a low-MAC diet. After mice generated a litter of pups that were weaned, low-MAC diet mice were switched to the high-MAC diet for 4 weeks. A parallel group of control mice were maintained on the high-MAC diet throughout (generation 2, n=6; generation 3, n=6; generation 4, n=5). b, Microbiota diversity as measured by Shannon index observed in the microbiota of mice at five weeks old (top panel, n=6 for each group) or four weeks after shift to high-MAC diet (bottom panel, n=6 for each group) from three generations of diet switching mice (grey) or control high-MAC diet mice (black). Error bars are shown as s.e.m and P values are from two-tailed Student’s t-test. c, Principal coordinate analysis of UniFrac distance for 16S rRNA amplicon profiles from fecal samples collected from first generation mice from the control group consuming a high-MAC diet (green, n=5) or the diet switching group from generation 1 (yellow, n=5), 2 (blue, n=6), 3 (red, n=6), and 4 (purple, n=6). d, Heat map of abundance of high-confidence OTUs (number of sequencing reads, columns) from the diet switching group (top panel) and controls (bottom panel); taxonomic assignment is indicated at the top of each column (Bacteroidetes, green; Firmicutes, orange; other, grey). Each row represents an individual mouse microbiota from four weeks post-humanization (initial), while consuming the low-MAC diet (week 9, lo, shaded yellow), and four weeks after switching to the high-MAC diet (week 15, hi, shaded grey). Corresponding time points from controls are similarly shaded. N=5, 6, 6, and 6 for the diet-switching group and n=5, 6, 6, and 5 for the control group for generations one through four respectively.