Metabolic interactions between members of the microbiota are attracting more attention because two microbes working together can make a reaction catalyzed by one of them more effective. Consider an...

Metabolic interactions between members of the microbiota are attracting more attention because two microbes working together can make a reaction catalyzed by one of them more effective. Consider an association between a polysaccharide-fermenting microbe and a methanogen in the colon. Consider also that the overall energy of a reaction depends on the ratio of substrate to end products for a bacterium like a polysaccharide fermenter. Can you explain why a polysaccharide fermenter and a methanogen might team up in the colon?