The right diet could play a crucial role in the survival of the slow loris

Tuesday, 12 March 2019

Slow Loris web

A new study provides insights into the diet and microbiomes in the gut of the slow loris and could lead to important interventions for the endangered primate.

The Javan slow loris (Nycticebus javanicus) is one of the world’s most endangered primates, threatened due to habitat loss and hunting for illegal pet ownership and use in traditional “medicines”.

Slow lorises have a highly specialised diet of tree gums and nectar and have been notoriously difficult to release to the wild successfully. This study shows what an important role the gut microbiome may have in helping animals to survive.

Professor Anna Nekaris, Professor in Primate Conservation

According to a new study published in the Nature Research journal Scientific Reports, a high-fibre diet especially of tree gums significantly increased microbe diversity in the stomachs of slow lorises rescued from pet trade held in rescue centres, improving their chances of survival when reintroduced into the wild.

Professor Anna Nekaris, Professor in Primate Conservation at Oxford Brookes University and Director of the Little Fireface Project in Java where the research was conducted, was part of the research team. She commented: "Slow lorises have a highly specialised diet of tree gums and nectar and have been notoriously difficult to release to the wild successfully. This study shows what an important role the gut microbiome may have in helping animals to survive."

Many health issues can now be linked with gut microflora. The researchers involved in the study noted that understanding the diversity of the microbiome is promising, especially for conservation work involving the reintroduction of the slow loris, and indeed other animals, into the wild.

Dr Francis Cabana, wildlife nutritionist for Wildlife Reserves Singapore who completed the fieldwork for the study, added: “We already know nutrition is really important for health, longevity, reproduction and behaviour, but now we can understand how nutrition is intimately involved with mammal microbiomes, which can turn on and off genes, absorb energy and even control metabolism”.

Several factors can affect the gut microbe of the animals including genetics or diet. With increased knowledge of the microbiome, it may become possible to predict the health of the primates, especially when comparing with wild individuals of the same species.

The gut microbial structure of the slow loris has been shown to have a strong link with immune system function. A microbiome of a captive animal that is comparable to wild animals, could therefore increase the success of transfer into the wild.

Captivity may have a detrimental effect on animal microbiomes, as has been reported for primates, leading to a state of microbial imbalance known as dysbiosis. Introducing animals rescued from trade back to the wild is already an unpredictable and stressful event for the primate.

Releasing an animal with an unbalanced microbiome may further reduce success rates, since their lowered microbial diversity may make them less adaptive to their environment and reduce their probability of survival.

Such insights may be even more vital for rescue centres with limited budgets in helping them to provide more appropriate diets for some of the world’s most threatened species.

A change in diet during the rehabilitation phase into one that resembles a diet eaten in the wild, could alter the microbiome of the slow loris and be beneficial to their health. It may also serve as a stepping stone leading to letting the primate survive on its own.

You can find out more about the research, teaching and conservation work by Professor Anna Nekaris and primate conservation at Oxford Brookes on the University’s website

The paper is available to read on the Nature Research website