(P20-036-23) Effect of Almond Snacking on Gut Microbiome in Adults With Overweight or Obesity

Objectives: To determine the extent to which daily almond intake (42.5 g/d) for 4-weeks modulates the gut microbiome in adults who have overweight or obesity.

Methods: The study was a randomized controlled, crossover, feeding trial conducted in individuals (age 30-70 years) with overweight or obesity. Each diet period was 4-weeks, followed by a 2‐week compliance break. Participants consumed each of the two isocaloric, weight maintenance diets: (1) no treatment foods (average American diet; AAD), and (2) 42.5 g/d of almonds (almond diet; ALD). Forty‐eight participants were originally recuited of which 18 completed the AAD arm while 15 completed the ALD intervention. Fecal specimens collected from these 15 subjects at a single baseline and endpoint of AAD and ALD intervention were used. Gut microbiome was assessed with high-throughput metagenomic shotgun sequencing.

Results: There was no difference between microbiome alpha-diversity at baseline, AAD, or ALD; however, both diets induced significant shifts in microbiome beta-diversity compared to baseline. The two interventions exhibited distinct microbial structures, with divergent impacts on the microbiome. AAD reduced the abundance of gut commensal Bifidobacterium animalis species and lactic-acid bacteria Leuconostoc and Lactobacillus genera compared to baseline. In contrast, ALD intervention, versus baseline, led to enrichment of Clostridium AM33-3 and AM22-11AC species and unclassified Ruminococcaceae genus (SCFAs-producing group) while reducing Lactococcus lactis and Lachnoclostridium and Lactobacillus genera. Additionally, ALD intervention showed a tendency to foster butyrate-producing bacteria including Faecalibacterium and Lachnospira eligens. Compared to AAD, ALD intake exhibited higher abundance of species within the Lachnospiraceae family, which is known to possess enzymes that facilitate the breakdown of complex carbohydrates and production of SCFAs, whereas AAD had more lactic-acid bacteria including Lacticaseibacillus rhamnosus, Streptococcus thermophilus, Limosilactobacillus fermentum, and Lactococcus lactis.

Conclusions: The findings demonstrate modulatory effects of almond intake on gut microbiome and suggest that almonds may have a favorable effect on gut health by fostering specific commensal/beneficial gut bacteria.

Funding Sources: Almond Board of California