New research suggests gut bacteria could have an influence over one's food choices.
The findings made by researchers from UC San Francisco, Arizona State University and University of New Mexico suggest bacteria influence cravings that provide the nutrients the thrive best on. Some bacteria species prefer fat while others are better suited to live off sugar.
The team believes these gut microbes may influence cravings by releasing signaling molecule; since the gut is linked to the immune, endocrine, and nervous systems the signals could evoke a behavioral response.
"Bacteria within the gut are manipulative," said Carlo Maley, PhD, director of the UCSF Center for Evolution and Cancer and corresponding author on the paper." "There is a diversity of interests represented in the microbiome, some aligned with our own dietary goals, and others not."
Humans can also influence these bacteria by altering what we eat; a dietary change can cause changes in the gut microbiome after only 24 hours.
"Our diets have a huge impact on microbial populations in the gut," Maley said. "It's a whole ecosystem, and it's evolving on the time scale of minutes."
The gut bacteria could be influencing our eating decisions through 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 senior author Athena Aktipis, PhD, co-founder of the Center for Evolution and Cancer with the Helen Diller Family Comprehensive Cancer Center at UCSF.
Influencing bacteria populations in the gut by killing off some species and encouraging others could help humans to live healthier and less-obese lives. They are easily influenced by prebiotics, antibiotics, and probiotics.
"Targeting the microbiome could open up possibilities for preventing a variety of disease from obesity and diabetes to cancers of the gastro-intestinal tract. We are only beginning to scratch the surface of the importance of the microbiome for human health," Aktipis said.
The findings were published this week in BioEssays.
