A handful of peanuts and a handful of herbs and spices may boost gut health, according to two separate studies from Pennsylvania State University.
Trillions of individual microorganisms, including hundreds to thousands of species of bacteria, viruses and fungi, live in the human gastrointestinal tract. Collectively known as the gut microbiome, they are so important to our health that scientists consider them a supporting organ.
Diet, exercise and medications are just some of the factors that affect the makeup of a person’s gut, which means that each person’s gut community is unique.
If your gut microbiome isn’t properly fed and properly nurtured, harmful microbes proliferate, and commensal microbes have more trouble handling tasks like our immune system and breaking down food.
Scientists are still trying to figure out which traits mark the healthiest gut communities, but as the research progresses, they’re starting to have better ideas.
“Studies have shown that people with a lot of diverse microbes have better health and better diets than those who don’t have much bacterial diversity,” explains nutritionist Penny M. Kris-Etherton.
While we generally think of our diets in terms of basics, like vegetables and meat, a lot of our cultural and personal preferences come down to the way we add some zest to our meals.
Kris-Etherton and her colleagues at Penn State were among the first to study the effects of herbs and spices on the composition of the human gut.
In their study, 54 adult participants at risk for cardiovascular disease participated in a 4-week randomized controlled feeding experiment.
During the trial period, everyone stuck to the same generic menu, which was designed to reflect the average American diet. Some participants were asked to add 0.5 grams (about 0.2 ounces) of the spice to their meals, while others were asked to add 3.3 grams or 6.6 grams.
The spice blend includes cinnamon, ginger, cumin, turmeric, rosemary, oregano, basil and thyme. Meanwhile, a control group was asked not to add these spices to their food.
Fecal samples taken before and after the experiment showed that diets with more spices tended to exhibit greater bacterial diversity.
“It’s a very simple thing that people can do,” Kris-Etherton said.
“The average American diet is far from ideal, so I think everyone can benefit from adding herbs and spices. It’s also a way to reduce the amount of sodium in your diet, but by flavoring foods to make them palatable, and actually It was delicious!”
The new findings support recent research showing that herbs and spices are natural prebiotics that nourish healthy bacteria in the human gut.
In 2019, a randomized, placebo-controlled, double-blind pilot study found that 5-gram capsules of a spice mix containing cinnamon, oregano, ginger, black pepper, and cayenne trigger changes in the gut microbiome within a few weeks.
In the more recent study, however, the spice blend was slightly different and incorporated directly into the participants’ daily diets.
Those who ate moderate and high amounts of the spice, equivalent to about 3/4 teaspoon and about 1 1/2 teaspoon per day, showed a greater abundance of gut bacteria called Ruminococcus. This family of microbes is generally more abundant in healthier adults, although its exact role in the gut is uncertain.
Those participants in the study who ate the spice also showed lower amounts of pro-inflammatory molecules in their gut, suggesting a possible anti-inflammatory effect.
More research is needed to figure out which spices affect gut microbes and why, but this isn’t the only dietary supplement that seems to boost certain gut bacteria.
A recent randomized controlled trial, also from Penn State University, recently investigated the effects of peanuts on the microbiome for the first time.
The study was conducted over six weeks and included 50 adults who ate the same diet every day. At the end of each day, after dinner and before bed, participants ate either 28 grams of dry-roasted, unsalted peanuts, or a small cheese and cracker.
In the group that snacked on nuts, as with spices in previous studies, Ruminococcus bacteria were significantly more abundant in the guts of participants at the end of the study.
There’s still a lot scientists don’t know about the gut microbiome, but for now, adding a little spice to your diet probably won’t hurt – It might even help. If nothing else, it adds some flavor.
Spice research published in nutrition magazinethe peanut study published in clinical nutrition.