This Night-Time Snack May Alter Gut Bacteria and Support Metabolic Health: Study Finds - Video

A new study published in the journal Current Developments in Nutrition has found that eating pistachios at night may positively influence gut bacteria in adults with prediabetes. Led by Kristina Petersen, associate professor of nutritional sciences at Penn State, the research highlights a potential new dietary approach for people at risk of developing Type 2 diabetes, though further investigation is needed to confirm long-term health benefits.

Prediabetes affects roughly one-third of people in the United States, and many go on to develop full-blown diabetes. While dietary changes are often recommended, there are limited proven strategies for prevention. Pistachios, rich in fiber and antioxidants, have already shown promise in improving markers of diet quality. However, their effects on the gut microbiome, a crucial factor in glucose regulation and inflammation, remained largely unexplored.

To study this, researchers enrolled 51 adults with prediabetes in a randomized crossover clinical trial. Participants were asked to consume a nighttime snack for 12 weeks: either two ounces of pistachios or a carbohydrate-based alternative providing 15 to 30 grams of carbs, such as slices of whole-grain bread. After a break, participants switched to the other snack option, allowing scientists to observe differences within the same individuals. Stool samples were analyzed using 16S rRNA gene sequencing to assess changes in gut bacteria.

The study found that pistachio consumption significantly altered the gut microbiome compared to the carbohydrate snack. Beneficial bacteria like Roseburia and Lachnospiraceae, known producers of the anti-inflammatory compound butyrate, increased. Meanwhile, bacteria linked to negative metabolic outcomes, such as Blautia hydrogenotrophica and Eubacterium flavonifractor, were reduced.

“Pistachios seem to be able to meaningfully shift the gut microbial landscape in adults with prediabetes especially when consumed as a nighttime snack,” said Petersen. However, she noted that more research is needed to determine if these microbial shifts translate into improved metabolic or inflammatory health outcomes.

Reference: https://www.psu.edu/news/health-and-human-development/story/nighttime-pistachio-snacking-may-reshape-gut-microbiome