Eating avocado as part of your daily diet may help improve gut health, according to a new study from the University of Illinois. Avocados are a healthy food rich in dietary fiber and monounsaturated fats. However, it was not clear how avocados affect the microbes in the gastrointestinal tract or "gut".
“We know that eating avocados makes you feel full and lowers blood cholesterol, but we didn't know how it affects the gut microbes and the metabolites the microbes produce,” said Sharon Thompson, graduate student in the Department of Nutritional Sciences. and lead author of the study.
The researchers found that people who ate avocado every day as part of a meal had more 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.
“Microbial metabolites are compounds that the microbes produce and that affect health,” says Thompson. “Consumption of avocados reduced bile acids and increased short-chain fatty acids. These changes correlate with favorable health outcomes.”
The study included 163 adults between the ages of 25 and 45 who were overweight or obese – defined as a BMI of at least 25 kg/m2 – but otherwise healthy. They were given one meal a day to consume as a substitute for breakfast, lunch, or dinner. One group ate an avocado with every meal, while the control group ate a similar meal, but without the avocado. The participants provided blood, urine, and stool samples throughout the 12-week study. They also reported how much of the meals they ate, and every four weeks they recorded everything they ate.
While other research on avocado consumption focused on weight loss, participants in this study were not advised to limit or change what they ate. Instead, they consumed their normal diet, with the exception of replacing one meal a day with the one the researchers gave.
The purpose of this study was to investigate the effects of avocado consumption on the gastrointestinal microbiota, said Hannah Holscher, assistant professor of nutrition in the Department of Food Science and Human Nutrition and senior author of the study.
“Our aim was to test the hypothesis that the fats and fiber in avocados have a positive influence on the intestinal flora. We also wanted to investigate the relationships between gut microbes and health outcomes,” says Holscher.
Avocados are high in fat; However, the researchers found that while the avocado group consumed slightly more calories than the control group, slightly more fat was excreted in their stools.
“Greater fat excretion means that the study participants absorbed less energy from the food they ate. This was probably due to a decrease in bile acids, which are molecules that our digestive system secretes and allow us to absorb fat. We found that the amount of bile acids in the stool was lower and the amount of fat in the stool was higher in the avocado group," explains Holscher.
Different types of fats have different effects on the microbiome. The fats in avocados are monounsaturated, which are heart-healthy fats.
The soluble fiber content is also very important, notes Holscher. A medium avocado provides about 12 grams of fiber, which goes a long way towards the recommended amount of 28 to 34 grams of fiber per day.
Eating fiber isn't just good for us; it is also important for the microbiome, says Holscher. “We can't break down dietary fiber, but certain gut microbes can. If we consume dietary fiber, it is a win-win for gut microbes and for us.”
Avocado is an energy-rich food, but it's also rich in nutrients and contains important micronutrients that we don't eat enough of, such as potassium and fiber.
