Bat guts become less healthy thanks to banana plantation ‘fast food’ diet
Newswise – Bats feeding on nectar in intensively managed banana plantations in Costa Rica have a less diverse set of gut microbes than bats feeding in their natural forest habitat or organic plantations, reveals a new research published today in Frontiers in ecology and evolution. This is the first study to show an association between habitat alteration, sustainable agriculture and the gut microbiota of wildlife.
“Both organic and conventional monoculture banana plantations provide a very reliable food source for some bat species that feed on nectar. However, the bats that foraged in the intensively managed plantations exhibited a reduced diversity of gut microbes, which could be a sign of gut dysbiosis, an unhealthy imbalance of its microbial symbionts, ”explains Priscilla Alpízar, first author of this study, a doctoral candidate at the Institute for Evolutionary Ecology and Conservation Genomics at the University of Ulm in Germany.
“In contrast, bats that fed in organic banana plantations had diverse and individualized gut microbiota that looked more like their natural counterparts that feed on the forest. ”
Fast food reduces bacterial diversity
Gut dysbiosis is a persistent imbalance in the gut microbial community and has been associated with poor health, such as increased susceptibility to disease. Studies in humans have shown that a fast food diet can cause dysbiosis by reducing the diversity of bacteria in the gut. This is one of the first studies to show that a similar effect can occur in wildlife.
“We wanted to explore the impact of intensive plantations consisting of large areas of bananas only on local fauna and understand whether sustainable agriculture has the same effects,” explains Alpizar.
Researchers examined fecal samples from bats feeding in organic and intensive banana plantations, as well as bats feeding in their natural habitat, to find out which bacterial groups were present, absent, more common, or linked to habitat. specific. They also measured the bat’s body condition, which included its size and weight.
“The bats that foraged in both conventional and organic banana plantations were larger and heavier than their forest counterparts, suggesting that the plantations are a reliable food source. »Reports Alpízar.
Loss of useful bacteria?
“We have found an interesting link between the composition of the gut microbiome and the condition of bats. Some gut bacteria were only associated with bats with higher residual body mass and those from natural forests, suggesting that these microbes may play a role in fat deposition. Since bats that forage in banana plantations don’t need to travel long distances to look for food, it makes sense that these bats don’t need the special help of bacteria to find food. store fat. However, for forest bats fat deposition is important because the food is seasonal and widely distributed in patches.
More research is needed to understand whether pesticides, or the provision of an abundant but unique food source, cause changes in the bat’s gut microbiota, and further, if there are long-term consequences. term for bat health.
“Our study shows that more sustainable farming practices can have less impact on wildlife. Hopefully our findings can lead collaborative efforts with producers and consumers to find more sustainable and bat-friendly farming practices, ”Alpízar concludes.