(OR08-02-26) Associations Between Ultra-Processed Food Intake, Diet Quality, and Oro-Gut Microbiome in Young Adults

Objectives: Ultra-processed foods (UPFs) contribute substantially to energy intake in young adults. Higher UPF intake is associated with poorer diet quality and adverse metabolic outcomes, yet relationships with the gut and oral microbiomes remain poorly defined. Herein, we examined associations between UPF intake, diet quality, anthropometrics, and oro-gut microbiomes in young adults. We hypothesized that higher UPF intake would be associated with poorer diet quality and altered microbial community composition.

Methods: This cross-sectional study included 51 college aged adults (33F/18M; mean age 21.1 ± 3.4 years). Participants completed 3-day food records classified using the NOVA system. UPF intake was calculated as percent of total energy and stratified into quartiles ( < 34%, 34-49%, 50-64%, ≥65%). Anthropometrics, blood pressure, and HbA1c were measured. Oral and fecal samples were collected for 16S rRNA sequencing. Differences across UPF quartiles were assessed using ANOVA. Associations between UPF intake, diet, and microbial taxa were evaluated using FDR-corrected Spearman correlations, and community composition using PERMANOVA.

Results: UPF intake was positively associated with energy, fat, carbohydrate, added sugar, and refined grain intake and inversely associated with whole grains and dark green vegetables (all p < 0.05). UPF intake was also positively associated with body weight (p < 0.05), while no associations were observed with blood pressure, HbA1c. Alpha- and beta-diversity of oral and fecal microbiomes did not differ across UPF quartiles. Several oral taxa showed trend level differences across quartiles, including Veillonella and Megasphaera (p < 0.1), both higher in the highest UPF quartile. Additional trend level associations were observed for ecal Bacteroides, Akkermansia, and oral Neisseria. Fiber was positively associated with Lachnospiraceae and Fusicatenibacter, while added sugar was positively associated with fecal Blautia and oral Streptococcus and Megasphaera (all p < 0.05).

Conclusions: UPF intake was associated with poorer diet quality and greater body mass but showed limited associations with metabolic markers. Microbiome associations were modest and appeared more strongly related to specific taxa and nutrient exposures than to UPF intake alone.

Funding Sources: Florida State University