In between pints he noticed that there was this layer of gas above the fermentation vats.

畅饮之余，他注意到发酵桶上方有一层气体。

That's because it can be way cheaper to cultivate tobacco plants in a field than to grow genetically modified yeast and other microbes indoors in large fermenters.

这是因为野外种植，型发酵桶中培养转基因酵母和其他微生物要便宜得多。

What they eventually find, is that the guy has an over-abundance of brewer's yeast in his digestive system, and it's basically turning his guts into a fermentation vat, converting carbohydrate sugars into ethanol, and getting him sloshed.

他们最终发现，这个人的消化系统中有过多的啤酒酵母，这本质上将他的胆变成了一个发酵桶，可以将糖类糖转化为乙醇，让他酩酊醉。