Fig. 1.

Summary scheme for cohousing experiment (see Fig. S1 for further details). Dams (n = 20) were bred and randomly assigned to become Control (water) or STAT (1 mg/kg body weight penicillin G) when pregnancy was detected. The antibiotic treatment continued until their 105 pups were weaned at week 4. Of these pups, 57 were not cohoused and 48 were used for cohousing. After a 3-day wash-out period, mice were either litter-mixed within treatment (non-cohoused) or mixed at a 1:1 ratio of STAT:Control within one cage (cohoused). The mice were changed to 45% high-fat diet at week 16. Fecal pellets and scale weight were collected 1–5 times/week starting at week 3. We also collected blood at ~16 and 26 weeks and performed two glucose tolerance tests, with the final test having a paired insulin tolerance test