World Half Full
Avocados are good for gut health
Eating avocados can improve gut health, researchers at the University of Illinois have found. While avocados are high in dietary fibre and monounsaturated fat, it hasn’t been clear how they affect the microbes in the gastrointestinal system or “gut”.
This new study reports that people who eat avocado every day as part of a meal had a greater abundance of gut microbes that break down fibre and produce metabolites that support gut health. They also had greater microbial diversity compared to people who didn’t eat avocado.
The study included 163 adults aged between 25 and 45, who were overweight or obese, as defined by having a BMI of at least 25, but otherwise healthy. One group in the study received one meal with avocado each day to replace either breakfast, lunch, or dinner, while the control group had a similar meal but without avocado. Participants provided blood, urine, and fecal samples throughout the 12-week study. They also reported how much of each meal they consumed, and every four weeks recorded everything they ate.
While other research on avocados has focused on weight loss, participants weren’t asked to restrict or change their diets, except for the replacement meal the researchers provided.
The study wanted to see how avocados affected gastrointestinal microbiota, says Hannah Holscher, assistant professor of nutrition in the university’s Department of Food Science and Human Nutrition and senior author of the study. “Our goal was to test the hypothesis that the fats and the fibre in avocados positively affect the gut microbiota. We also wanted to explore the relationships between gut microbes and health outcomes,” she says.
Avocados are rich in fat; however, the researchers found that while the avocado group consumed slightly more calories than the control group, they excreted slightly more fat in their stools. “Greater fat excretion means the research participants were absorbing less energy from the foods they were eating. 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,” Holscher explains.
Different types of fats have different effects on the microbiome. Soluble fibre content is also very important, Holscher notes. A medium avocado provides around 12 grams of fibre, which goes a long way toward meeting the recommended amount of 28–34 grams of fibre a day.
“Less than 5% of Americans eat enough fibre. Most people consume around 12–16 grams of fibre per day. Thus, incorporating avocados in your diet can help get you closer to meeting the fibre recommendation,” she notes.
Eating fibre isn’t just good for us, it’s important for the microbiome, too, Holscher says. “We can’t break down dietary fibres, but certain gut microbes can. When we consume dietary fibre, it’s a win-win for gut microbes and for us.
“Just like we think about heart-healthy meals, we need to also be thinking about gut-healthy meals and how to feed the microbiota,” she explains. “It’s just a really nicely packaged fruit that contains nutrients that are important for health. Our work shows we can add benefits to gut health to that list,” Holscher concludes.