Fresh faecal samples were obtained from 6 consenting healthy adult human donors (1 faecal sample per donor - minimum 0.5g) and were placed in anaerobic conditions within 1 hour of passing to preserve the viability of anaerobic bacteria. All sample processing and culturing took place under anaerobic conditions in a Whitley DG250 workstation (Don Whitley, West Yorkshire, UK) at 37°C. Culture media, phosphate-buffered saline (PBS) and all other materials that were used for culturing were placed in the anaerobic cabinet 24 hours before use to reduce to anaerobic conditions. The faecal samples were divided in two. One part was homogenised in reduced PBS (0.1g stool/ml PBS) and was serially diluted and plated directly onto YCFA7 (link) agar supplemented with 0.002g/ml each of glucose, maltose and cellobiose in large (13.5cm diameter) petri dishes This sample was also subjected to metagenomic sequencing to profile the entire community. The other part was treated with an equal volume of 70% (v/v) ethanol for 4 hours at room temperature under ambient aerobic conditions to kill vegetative cells. Then, the solid material was washed 3 times with PBS and it was eventually resuspended in PBS. Plating was performed as described above.
For the ethanol-treated samples, the medium was supplemented with 0.1% sodium taurocholate to stimulate spore germination. Colonies were picked 72 hours after plating from petri dishes of both ethanol-treated and non-ethanol-treated conditions harbouring non-confluent growth, (i.e. plates on which the colonies were distinct and not touching). The colonies that were picked were re-streaked to confirm purity.