Ape Gut ‘Lifestyle Makeup’ Reveals Human Impact, Health Clues
The intricate world within the gut, teeming with bacteria, holds surprising secrets about how environment shapes biology. A study from Washington University in St. Louis reveals that the gut microbial communities of apes in U.S. zoos mirror those of humans following non-Western diets more closely than their wild counterparts. This research highlights how human proximity influences primate gut health and provides a unique window into the complex Lifestyle Makeup of these microbial ecosystems, offering insights for both ape conservation and human health, particularly concerning antibiotic resistance.
The Research Connecting Humans and Apes
Understanding the factors that shape gut microbiomes is crucial, as these internal ecosystems provide essential vitamins, aid digestion, regulate inflammation, and protect against pathogens. Senior author Dr. Gautam Dantas, a professor at Washington University School of Medicine, noted the difficulty in studying antibiotic effects on human microbiomes often already exposed to resistance genes. “Wild apes are the closest thing we have to pre-antibiotics humans,” Dantas explained, highlighting the significance of collaborating with leading primatologists Dr. Crickette Sanz and Dr. David Morgan.
Sanz, an associate professor of biological anthropology at Washington University, and Morgan, a research fellow at Lincoln Park Zoo’s Lester E. Fisher Center for the Study and Conservation of Apes, conduct research in the remote Nouabalé-Ndoki National Park in the Republic of Congo. Their teams meticulously collected fecal samples from 18 wild chimpanzees and 28 wild gorillas using noninvasive methods, preserving the samples through a complex journey involving liquid nitrogen, dugout canoes, and freezers before reaching Dantas’ lab. Samples from 81 local humans near the park were also collected, alongside samples from 18 chimpanzees and 15 gorillas residing in the Saint Louis Zoo and Lincoln Park Zoo.
Researchers Crickette Sanz and Aimé Galou Ossette track wild apes in Congo rainforest for primate conservation study
Contrasting Gut ‘Lifestyle Makeup’: Wild vs. Captive Apes
The analysis, led by first author Dr. Tayte Campbell, compared the bacterial types and antibiotic resistance genes across the ape and human samples, incorporating public data from diverse human populations (hunter-gatherers, rural agriculturalists, urban dwellers). The results showed distinct groupings based on gut microbiome composition.
Human gut microbiomes split into two main categories: one including hunter-gatherers and rural agriculturalists (like the Congo villagers) consuming plant-heavy, low-fat diets, and another comprising urban individuals eating meat-rich Western diets. Wild gorillas and chimpanzees formed a unique third group, distinct from both human clusters. Intriguingly, captive apes did not cluster with their wild relatives; instead, their gut Lifestyle Makeup closely resembled that of humans consuming non-Western, plant-rich diets, suggesting diet and environment heavily influence this microbial composition.
Unforeseen Discovery: Antibiotic Resistance in the Wild
A striking finding was the presence of antibiotic resistance genes even within the microbiomes of wild apes who have presumably never encountered antibiotics directly. The researchers, along with the local human population in Congo, harbored several previously unknown resistance genes. Among these was a gene conferring resistance to colistin, a critical last-resort antibiotic used in human medicine.
While these genes currently reside in bacteria not considered harmful to humans, the potential for horizontal gene transfer – where bacteria share genetic material – raises concerns. Such transfers could eventually introduce potent resistance mechanisms into dangerous human pathogens.
Implications for Conservation and Human Health
These findings have significant implications beyond basic science. “Chimpanzees are endangered, and Western lowland gorillas are critically endangered,” Sanz stated. “Measuring the gut microbiome could be a way to monitor apes’ exposure to anthropogenic threats so we can identify areas of concern and develop effective, evidence-based mitigation strategies.” The gut lifestyle makeup acts as an indicator of environmental pressures.
Furthermore, studying these wild populations provides a unique opportunity for public health surveillance. “When we find these novel antibiotic resistance genes in the environment, we can study them and possibly find ways to inhibit them before they show up in human pathogens,” Campbell noted. This proactive approach could be vital in combating future health crises. Morgan added the importance of expanding research into areas with varying human activity levels, like logging zones, to better understand how antibiotic resistance spreads through natural environments and its potential impact back on human populations.
Conclusion
The study underscores the profound impact of lifestyle and environment on the gut’s microbial composition, or lifestyle makeup, in both humans and our closest animal relatives. The microbiomes of captive apes align more with non-Western human diets than with wild apes, demonstrating environmental influence. Critically, the discovery of antibiotic resistance genes in remote wild ape populations highlights an underappreciated pathway for resistance spread and offers a vital early-warning system for potential threats to human health. This research, published in The ISME Journal, emphasizes the interconnectedness of wildlife conservation and public health, urging further investigation into these complex microbial ecosystems.
