For the peanut study, which was published in the journal Clinical Nutrition, Kris-Etherton and her colleagues compared the effects of snacking on 28 grams (approx. 1 ounce) of peanuts per day, versus a higher carbohydrate snack—crackers and cheese. At the end of six weeks, participants who ate the peanut snack showed an increased abundance of Ruminococcaceae, a group of bacteria linked to healthy liver metabolism and immune function.
In the herbs and spices study, which was published in The Journal of Nutrition, scientists analyzed the impact of adding blends of herbs and spices — such as cinnamon, ginger, cumin, turmeric, rosemary, oregano, basil, and thyme — to the controlled diets of participants at risk for cardiovascular disease. The team examined three doses — about 1/8 teaspoon per day, a little more than 3/4 teaspoon per day, and about 1 1/2 teaspoon per day. At the end of four weeks, participants showed an increase in gut bacteria diversity, including an increase in Ruminococcaceae, most notably with the medium and high doses of herbs and spices.
A global study involving over 50,000 participants links the presence of gut Blastocystis, traditionally seen as a parasite, with improved cardiovascular health and reduced body fat, suggesting beneficial effects on cardiometabolic health. Further research is required to validate these findings.