A new study of chimpanzees and gorillas offers clues about how diet may affect human disease. The research was led by food scientists from Columbia University. Collecting feces from free-ranging apes in the Republic of Congo for three years, they investigated seasonal shifts in the microbiome, the bacterial community of the ape intestine.
While fruits are in season, they make up about 70 percent of the diet of western lowland gorillas. Fruits are rich in easily digested sugars but low in fibre. During the dry season gorillas switch to their regular fibre-rich diet of leaves and bark. Meanwhile, chimps are fruit specialists so their diet changes less. Analysis of microbial DNA from fecal samples showed that the bacteria shift in response to diet.
By now most of us know what we eat affects our risk for cancer. That probably relates to the microbiome, which helps digest our food and interacts with the immune system. New research is looking at the likely role of the microbiome in autoimmune diseases such as celiac and type 1 diabetes. Celiac disease involves an immune response to gluten in wheat, rye and barley. However, experts believe the rising prevalence of celiac disease relates to disturbances in the microbiome rather than an intrinsic human intolerance for gluten.
The ape story in Nature Communications points out the microbiome in hunter-gatherer societies, such as Hadza people of Tanzania, mirrors seasonal shifts observed in gorillas and chimps. This casts doubt on the notion of a static microbiome. The supermarket diet eliminates seasonal changes and makes foods available all year that are tasty but not necessarily healthy. In ScienceDaily, Brent Williams, PhD, an author of the study, comments many people may be living with constant fibre deficiency.
This research also highlights the importance of conserving threatened species and ecosystems. They deserve protection for their own sakes.
However, from a selfish standpoint, humans should protect creatures that can help us understand ourselves and how to survive. Science is breaking down the boundary between us and other organisms like our close cousins and the bacteria that help nourish us. Gorillas and chimpanzees are our closest living relatives and both are endangered.
They possess essential information about who we are and where we came from. Losing them would threaten our own chances of survival.