Xanthan Gum

Xanthan gum is made by fermenting sugars with a bacterium, Xanthomonas campestris, and then purifying the result. Small amounts thicken gravies and pâtés and keep ingredients from separating, often together with guar or locust bean gum.

It passes through largely undigested, like a soluble fibre. It’s an approved food additive in the US, and the bacterium isn’t present in the finished ingredient.