When we eat, we feed not only ourselves but also the trillions of microbes inhabiting our guts. Just like us, these gut microbes produce metabolic byproducts, many of which impact our physiology in turn. Also like us, our gut microbes exhibit different behaviors in different contexts. These observations open up the possibilities of microbiome engineering (adding/depleting specific bacteria) and/or redirecting our gut microbiome in order to optimize our health outcomes.

Enteric neurons in the submucosal plexus labeled using anti-Tuj1 antibody
Enteric neurons in the submucosal plexus labeled using anti-Tuj1 antibody.

Gut motility

Diet and the gut microbiome represent key determinants of gut motility, a physiologic parameter governing digestion and nutrient absorption. We have shown that even just a single dietary ingredient (turmeric) can be used to manipulate motility in a microbiome-dependent bile acid-mediated manner via the enteric nervous system (ENS) (Dey et al., 2015), the network of approximately 500 million nerves that regulates gut physiology. We seek to elucidate how bile acids mediate interactions at the interface between gut microbes and the ENS.

Mucin lakes (blue) atop a colorectal carcinoma
Mucin lakes (blue) atop a colorectal carcinoma. Photo by Fred Hutch Experimental Histopathology

Gastrointestinal cancers

Secondary microbiome-generated metabolites such as bile acids shape cancer risk in the gastrointestinal tract. We seek to identify regulators of bacterial metabolism that can be targeted to ultimately cancer.