Gut bacteria may affect our eating behavior by releasing signals that tell our bodies to eat what is best for them and not necessarily for us, researchers said last week.
Image courtesy of dream designs at FreeDigitalPhotos.net
Microbes in our digestive tract fight with each other to live in the gut, and may also influence human dietary choices by inclining us to consume nutrients they best grow on. This is contrary to the notion that gut bacteria simply subsist on whatever we eat without exerting any effect.
“Bacteria within the gut are manipulative,” study co-author Carlo Maley said in a news release.
“There is a diversity of interests represented in the microbiome, some aligned with our own dietary goals, and others not.”
The microbiome refers to the diverse community of bacteria in the human body, which vastly outnumbers the cells in our bodies.
These bacteria could prefer nutrients such as fat or sugar, and scientists think they release signaling molecules into the gut, which is linked to the immune system, the endocrine system and the nervous system. These signals could then influence behavior by making certain foods more attractive.
How this exactly happens is unclear, although researchers suspect the role of the vagus nerve, which connects 100 million nerve cells from the digestive tract to the base of the brain.
“Microbes have the capacity to manipulate behavior and mood through altering the neural signals in the vagus nerve, changing taste receptors, producing toxins to make us feel bad, and releasing chemical rewards to make us feel good,” said co-author C. Athena Aktipis.
However, the researchers added that the reverse is also true: by ingesting ‘good’ bacteria or manipulating their levels by other means, we can create an environment that leads to good health for us. Taking probiotics or antibiotics and making dietary changes are some ways of manipulating bacteria so that the majority release signals that spur us to eat healthy food.
“Altering our microbiota offers a tractable approach to otherwise intractable problems of obesity and unhealthy eating,” wrote the authors.
Public Health View 