The Study
Link between ultra-processed foods and drinks intake, gut microbiota and inflammation: an exploratory analysis in adult volunteers.
This study looked at what people ate and then checked their poop and saliva to see if there was a pattern. It found that people who ate more processed foods had different gut bugs and more inflammation markers—but that doesn’t mean the food caused it. Maybe people who eat more processed food also sleep less or exercise less, and that’s what’s really changing their gut.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
This study looked at what people ate and checked their gut bacteria and inflammation markers to see if junk food changes their body.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 544 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1These changes are small but consistent with other studies suggesting junk food may harm gut health and trigger low-grade inflammation.
- 2People who ate more ultra-processed foods had less good bacteria (Faecalibacterium) and more bad bacteria (Hominimerdicola, Actinomyces), and higher levels of inflammation markers in saliva.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nutrition journal
Year
2026
Authors
L. Lengelé, M. Autuori, Emilie Bosteels, A. Neyrinck, Marie Rombaux, P. Cani, Valérie Dormal, Louise Deldicque, L. Bindels, N. Delzenne
Related Content
Claims (6)
About one-quarter of the American diet consists of ultra-processed foods with additives and flavor combinations that alter gut microbiota and lead to metabolic dysfunction.
Adults who consume more ultra-processed foods and drinks have lower levels of Faecalibacterium and higher levels of Hominimerdicola and Phocaeicola in their gut bacteria, along with higher levels of the inflammatory marker IL-1β in saliva.
Adults who drink more sugar-sweetened beverages have lower levels of exhaled breath hydrogen and higher levels of the inflammatory marker IL-6 in saliva.
Adults who consume more ultra-processed foods from the meat, fish, and cheese category have lower levels of Agathobacter and Coprococcus bacteria and higher levels of Actinomyces bacteria in their gut.
People who eat more ultra-processed foods have higher levels of IL-1β in their saliva, and these levels are linked to higher amounts of Phocaeicola bacteria and lower amounts of Faecalibacterium bacteria.
People who drink more sugar-sweetened beverages have higher levels of IL-6 in their saliva and different gut bacteria, with more Actinomyces and less Flintibacter.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.