A University of Glasgow study confirms something that owners of feisty ponies have long observed---diets high in starch can contribute to “spookier” behavior.
To investigate possible correlations between behavior and the gut micro-biome, the researchers used 10 untrained ponies. For two weeks, half of the ponies received a high-starch ration, and half were fed a high-fiber diet. The rations were then switched for an additional two-week period.
At the end of each 14-day feeding period, the researchers collected fecal samples from each pony and extracted DNA data from the bacteria present. They also performed two tests to gauge how the ponies reacted to various stimuli.
In the first test, an unfamiliar person stood passively in a small area with each pony. For the second test, each pony was released into an area where a novel object (a road sign or a box wrapped in tinfoil) had been placed next to a bowl of feed. The researchers documented each pony’s behavior in detail.
They found that the ponies were more reactive when they were on the high-starch diet, dem- onstrating a height- ened state of alert when confronted with the novel object, as well as what the researchers called “unsettled behaviors” in response to the passive human.
In addition, the DNA analysis indicated that the composition of gut bacterial populations was influenced by the different diets that the ponies received.
Comparing the behavior data to the genetic data, the researchers concluded that “correlative relationships exist between dietary induced alterations to fecal microbiota and behavior,” and that “dietary induced alterations to gut microbiota play a role in affecting the behavior of the host.”
Reference: “High-starch diets alter equine faecal microbiota and increase behavioural reactivity,” Scientific Reports, December 2019