Culturing Human and Mouse Bacteroides

Bacteroides ovatus (MDA-HVS BO001) was isolated and cultured from healthy volunteer’s stool samples in a Whitley anaerobic chamber (10% H₂, 5% CO₂ and 85% N₂). Human-derived B. ovatus (ATCC 8483) and human-derived B. theta (ATCC 29148) were purchased from American Type Culture Collection (ATCC). Mouse-derived BT (MDA-JAX BT001) was previously isolated^{15 (link)}. Bacterial number was quantified using a Nexcelom Cellometer cell counter with SYTO BC dye and propidium iodide. Bacterial growth experiments were performed in a liquid media, BYEM10, composed of a hybrid of BHI and M10 supplemented with yeast extract as previously described^{15 (link),45 (link)}. Bacteria were cultured up to 24 or 48 hours at a starting concentration of 1 × 10⁶ bacteria/ml in BYEM10 broth (pH 7.2) with or without 5 mg/ml of porcine gastric mucin (M1778, Sigma-Aldrich), wheat arabionoxylan (wheat flour; low viscosity; Megazyme), xylan (Beechwood; Megazyme), xyloglucan (Tamarind; Megazyme), or starch (wheat; Sigma-Aldrich). Optical densities (OD_{600 nm}) of bacterial cultures were measured with a BioTek Epoch 2 plate reader.