(LB02-17-25) Persea Americana for Total Health-2 (PATH-2): Randomized Crossover Complete Feeding Trial on the Effects of Avocado Consumption on Gastrointestinal Health

Objectives: We aimed to determine the impact of avocado consumption on the human gut microbiome composition and function.

Methods: Adults (n=43) with overweight and obesity (mean age 41y, BMI 31.6 kg/m²) participated in a randomized crossover study with three 4-wk conditions separated by 2-wk washouts: avocado (AV), average American (AA), and high oleic oils + fiber (OF). The study was a fully controlled feeding intervention in which the same base diet was consumed during each condition; the base diet was supplemented with 209 g/d avocado during the AV condition, an isocaloric snack that mimicked avocado’s fiber and MUFA profile during the OF condition, and an isocaloric snack that contained saturated fat and low fiber during the AA condition. Fecal, blood, and urine samples were collected at the end of each condition. Fecal microbiome, metabolites [(short-chain fatty acids (SCFA), branched-chain fatty acids (BCFA), ammonia, phenols, indole, and bile acids] were assessed through shotgun metagenomics and GC/MS and LC-MS/MS, respectively. Gut permeability was assessed through urinary excretion of sucralose, rhamnose, and mannitol between 0-2hrs (small intestine) and 8-24hr (colon) after consumption. Per-protocol (PP; ≥70% meal consumption) analyses were conducted using repeated measures ANOVA on linear mixed effects models (Friedman test was used for non-parametric comparisons) with post-hoc Benjamini Hochberg (BH) corrections.

Results: Fecal acetate concentrations (µmol/g DMB) were greater in the AV (311) and OF (291) compared to AA (246) (AV = OF > AA; p< 0.01). Total SCFA concentrations (µmol/g DMB) were greater in AV (456) and OF (448) vs. AA (389), (AV = OF > AA; p< 0.05). The SCFA-to-BCFA ratio was greater in AV than AA (AV > AA; AV=OF; OF=AA; p=0.01). There were no differences in fecal phenol, indole, or ammonia concentrations among groups. Fecal Parabacteroides relative abundance tended (p = 0.08) to be enriched with AV (2.12%) and OF (2.19%) compared to AA (1.79%). Lachnospira tended (p=0.08) to be enriched with OF (2.16%) compared to AV (1.00%) and AA (0.81%). There were no significant differences among groups for 24h urine sugar recovery, although the %recovery of the 3 sugars was numerically lower with AV compared to OF and AA.

Conclusions: Daily avocado consumption affected fecal microbiome composition and function.

Funding Sources: Avocado Nutrition Center