LB942 Prospective randomized controlled trial on the effects of almonds on the gut microbiome in association with the gut-skin axis and skin related effects

Abstract

Almonds are a rich source of fatty acids, phytochemical polyphenols, and antioxidants such as vitamin E. We previously showed that 24 weeks of almond consumption significantly decreased facial wrinkle severity and pigmentation. Sebum excretion increased in the control group while there was no increase in the almond group. Here, we analyze how the gut microbiome was altered after almond consumption and how this may contribute to the gut-skin axis. A prospective, randomized, placebo-controlled study included postmenopausal women (n=56) who consumed 20% of their daily energy consumption in either almonds (n=28) or calorie-matched snacks (n=28) for 24 weeks. Stool samples were analyzed with whole-genome sequencing to detect microbial abundance as well as functional gene expression. In the almond intervention group, there was a significant increase in Bacteroidetes phylum and in Butyricimonas virosa abundance (p<0.05), which are known short-chain fatty acid producers. The functional analysis demonstrated an increase in microbial queuosine biosynthesis, glycolysis VI, and mannitol cycle, and decrease in formaldehyde assimilation II (RuMP cycle) and superpathway of L-serine and glycine biosynthesis I in the almond intervention group (p<0.05). On the other hand, control snack supplementation was augmented for microbial glycogen degradation I (p<0.05), suggesting that there was an increased load of glucose to the gut in the control group, in agreement with the increased glucose content in the control group. The daily consumption of almonds may beneficially alter the gut microbiome in association with previously noted changes in the skin. Changes in the gut microbiome may also reflect the glycemic load of the food interventions.