One of the more important findings in this study was:

 

Roughly 20 percent of humans lack the gene that encodes proteins for processing a specific carbohydrate, a sugar in the intestinal mucus called fucose. The interaction shown by the research team is valuable because many bacteria are adept at utilizing carbohydrates such as fucose, which are abundant in the gut. Confronted with diets that have little or no complex plant sugars, these bacteria are forced to change their function, especially in hosts that lack fucose. This was seen with the altered metabolic gene expression of one of the key microbes in the gut -- Bacteroides thetaiotaomicron. Changes in microbial membership or function as demonstrated in this study may, in turn, foster a "digestive landscape" that can promote inflammatory conditions such as Crohn's disease.""