Orangutans in Borneo consume plants with antimicrobial and anti-inflammatory properties

Over two decades, researchers observed wild orangutans in Indonesian Borneo consuming plants that possess antimicrobial, anti-inflammatory, and wound-healing properties, suggesting these apes may use certain vegetation for medicinal purposes rather than solely for nutrition.

The study, led by Georgia Allen during her Masters in Conservation and Biodiversity at the University of Exeter, found that orangutans often ingest specific plant species in particular sequences, a behavior pattern resembling self-medication seen in other animals.

Allen noted, “At this stage, we cannot say that orangutans are consciously ‘diagnosing’ themselves in the same way humans would. However, our findings suggest they selectively consume certain plants with medicinal properties in ways that go beyond simple nutrition.” She added that several plants appeared together in the orangutan diet more frequently than chance would predict, many containing compounds linked to antimicrobial, anti-inflammatory, or wound-healing effects.

Importantly, many of these plants are not common components of the orangutan diet overall, implying they may be consumed for specific health benefits rather than as regular food sources.

Similar self-medicating behaviors have been documented in chimpanzees, bonobos, gibbons, and gorillas, with chimpanzees known to eat plants that reduce internal parasite infections.

The research was conducted in a peat swamp forest in Central Kalimantan, where some of the plants consumed by orangutans are also used medicinally by local Indigenous communities. This overlap highlights the importance of preserving Indigenous knowledge for biodiversity conservation and global health research.

The study, titled “Investigating medicinal resource combinations in the Bornean orangutan diet,” was published on 13 May 2026 in Scientific Reports by Georgia Allen and colleagues. The DOI is 10.1038/s41598-026-52614-4.

Funding for this research came from the US Fish and Wildlife Service, Great Ape Conservation Fund, the L.S.B. Leakey Foundation, ARCUS, The Orangutan Project (TOP), and Re:Wild. The study utilized long-term behavioral data collected through the Orangutan Behaviour Project in collaboration with the University of Palangka Raya – CIMTROP.