糖心视频

Whether we're talking about animals or humans, gut microbes are essential for health, metabolism and protecting against infection. While captivity is known to alter the gut microbiota of wildlife, the relative influence of diet, genetics and environment has been unclear, especially for endangered species. A new study in the journal PLOS One compared the gut microbes of wild and captive giant pandas, red pandas and Asiatic black bears and found that captivity has the biggest impact on their gut microbiome.

A team of researchers from China first conducted a poop test, collecting fresh fecal samples from wild and captive members of the three endangered species. Next, they used 16S rRNA V4 sequencing to identify all the different types of bacteria present in the samples. This technique identifies bacteria by analyzing a small section of their ribosomal RNA gene.

Finally, they processed all the data with powerful statistical tools, including PERMANOVA (Permutational Multivariate Analysis of Variance), which was used to score and rank the influence of factors like diet, genetics and captivity on the animals' gut microbiomes.

The researchers report that captivity (the environment), such as being in a research center or zoo, is the biggest single factor driving change in the gut microbiome structure (21.6%). The host animal's lineage explained 12.3% of the shift, while diet accounted for 3.9% of the change. Additionally, the gut bacteria of all three species became more similar to each other in captivity, even though they are distinct in the wild.

The findings also showed that diversity changed depending on the species. Captive giant pandas experienced a significant reduction in gut microbial diversity, most likely because their wild bamboo diet was reduced or replaced. However, red and black pandas experienced an increase in microbial diversity, which could be because they are omnivores and can respond better to the mixed diet they receive in captivity.

There was also a bacterial flip, which may cause a significant change in animals' digestive capabilities. Wild bears and pandas were dominated by proteobacteria that help with the breakdown of complex plant material, but in captivity, all species became dominated by firmicutes. This group is associated with the fermentation of starches and sugars that are common in captive diets.

One of the more concerning findings was that living in captivity led to an increase in potentially harmful bacteria such as Streptococcus and Escherichia鈥揝higella.

Reintroduction risk

As the researchers write in their paper, these changes can hamper conservation efforts by taking away essential microbial tools animals need for survival. "Our results carry critical warnings for reintroduction programs: the loss of wild-associated functional taxa and proliferation of opportunists in captivity may undermine host fitness post-release."

Therefore, the team is calling for conservationists to improve the conditions for captive animals and use probiotics or fecal transplants to restore wild-associated gut bacteria before reintroducing them into the wild.

漏 2025 Science X Network