Avocados (Persea americana) are rich in dietary fiber and monounsaturated fatty acids, nutrients that have been independently connected to metabolic health benefits and the gastrointestinal microbiota.
“We know eating avocados helps you feel full and reduces blood cholesterol concentration, but we did not know how it influences the gut microbes, and the metabolites the microbes produce,” said lead author Sharon Thompson, a graduate student in the Division of Nutritional Sciences at the University of Illinois, Urbana-Champaign.
“The purpose of this study was to explore the effects of avocado consumption on the gastrointestinal microbiota,” said senior author Dr. Hannah Holscher, a researcher in the Department of Food Science and Human Nutrition at the University of Illinois, Urbana-Champaign.
“Our goal was to test the hypothesis that the fats and the fiber in avocados positively affect the gut microbiota.”
“We also wanted to explore the relationships between gut microbes and health outcomes.”
The study involved 163 adults between 25 and 45 years of age with overweight or obesity but otherwise healthy.
The participants received 175 g (men) or 140 g (women) of fresh Hass avocado daily as part of a meal or an isocaloric control meal once per day for 12 weeks.
They provided blood, urine, and fecal samples throughout the study. They also reported how much of the provided meals they consumed, and every four weeks recorded everything they ate.
The researchers found that people who ate avocado every day as part of a meal had a greater abundance of gut microbes that break down fiber and produce metabolites that support gut health.
They also had greater microbial diversity compared to people who did not receive the avocado meals in the study.
Avocados are rich in fat; however, the scientists found that while the avocado group consumed slightly more calories than the control group, slightly more fat was excreted in their stool.
“Greater fat excretion means the research participants were absorbing less energy from the foods that they were eating,” Dr. Holscher said.
“This was likely because of reductions in bile acids, which are molecules our digestion system secretes that allow us to absorb fat.”
“We found that the amount of bile acids in stool was lower and the amount of fat in the stool was higher in the avocado group.”
“Soluble fiber content is also very important,” she added.
“A medium avocado provides around 12 grams of fiber, which goes a long way toward meeting the recommended amount of 28 to 34 grams of fiber per day.”
“Eating fiber isn’t just good for us; it’s important for the microbiome, too.”
“We can’t break down dietary fibers, but certain gut microbes can. When we consume dietary fiber, it’s a win-win for gut microbes and for us.”