@article {Bolte1287, author = {Laura A Bolte and Arnau Vich Vila and Floris Imhann and Valerie Collij and Ranko Gacesa and Vera Peters and Cisca Wijmenga and Alexander Kurilshikov and Marjo J E Campmans-Kuijpers and Jingyuan Fu and Gerard Dijkstra and Alexandra Zhernakova and Rinse K Weersma}, title = {Long-term dietary patterns are associated with pro-inflammatory and anti-inflammatory features of the gut microbiome}, volume = {70}, number = {7}, pages = {1287--1298}, year = {2021}, doi = {10.1136/gutjnl-2020-322670}, publisher = {BMJ Publishing Group}, abstract = {Objective The microbiome directly affects the balance of pro-inflammatory and anti-inflammatory responses in the gut. As microbes thrive on dietary substrates, the question arises whether we can nourish an anti-inflammatory gut ecosystem. We aim to unravel interactions between diet, gut microbiota and their functional ability to induce intestinal inflammation.Design We investigated the relation between 173 dietary factors and the microbiome of 1425 individuals spanning four cohorts: Crohn{\textquoteright}s disease, ulcerative colitis, irritable bowel syndrome and the general population. Shotgun metagenomic sequencing was performed to profile gut microbial composition and function. Dietary intake was assessed through food frequency questionnaires. We performed unsupervised clustering to identify dietary patterns and microbial clusters. Associations between diet and microbial features were explored per cohort, followed by a meta-analysis and heterogeneity estimation.Results We identified 38 associations between dietary patterns and microbial clusters. Moreover, 61 individual foods and nutrients were associated with 61 species and 249 metabolic pathways in the meta-analysis across healthy individuals and patients with IBS, Crohn{\textquoteright}s disease and UC (false discovery rate\<0.05). Processed foods and animal-derived foods were consistently associated with higher abundances of Firmicutes, Ruminococcus species of the Blautia genus and endotoxin synthesis pathways. The opposite was found for plant foods and fish, which were positively associated with short-chain fatty acid-producing commensals and pathways of nutrient metabolism.Conclusion We identified dietary patterns that consistently correlate with groups of bacteria with shared functional roles in both, health and disease. Moreover, specific foods and nutrients were associated with species known to infer mucosal protection and anti-inflammatory effects. We propose microbial mechanisms through which the diet affects inflammatory responses in the gut as a rationale for future intervention studies.All relevant data supporting the key findings of this study are available within the article and the supplementary files. Raw metagenomic sequencing reads and extended phenotypic data are available from the European Genome-phenome Archive data repository: 1000 IBD cohort [EGAD00001004194] and LifeLines Deep cohort [EGAD00001001991]. Codes used for generating the microbial profiles are publicly available at:[https://github.com/WeersmaLabIBD/Microbiome/blob/master/Protocol_metagenomic_pipeline.md]. All statistical analysis scripts are written in R and can be found here: https://github.com/WeersmaLabIBD/Microbiome/blob/master/Diet_Microbiome.md.}, issn = {0017-5749}, URL = {https://gut.bmj.com/content/70/7/1287}, eprint = {https://gut.bmj.com/content/70/7/1287.full.pdf}, journal = {Gut} }