Abbreviations GALT Gut associated lymphoid tissue B cells B lymphocytes T cells T lymphocytes NK Natural killer TC cell Cytotoxic T-cell TCR T cell receptor Treg Regulatory T cell Ig Immunoglobulin APC Antigen presenting cells MHC Major histocompatibility complex Th T helper IL Interleukin INF Interferon CXCL-10 C–X–C motif chemokine ligand 10 RANTES Regulated upon Activation, Normal T Cell Expressed and Presumably Secreted CCL-5 Chemokine (C–C motif) ligand 5 MCP-1 Monocyte Chemoattractant Protein-1 TGF-β Transforming growth factor-β Jak Janus kinase STAT Signal transducer and activator of transcription NFκB Nuclear factor kappa-light-chain-enhancer of activated B cells TNF Tumour necrosis factor PRRs Pattern recognition receptors MAMPs Microbe-associated molecular patterns TLRs Toll-like receptors NLR Nucleotide-Binding Domain, Leucine-Rich Repeat NALP3 NACHT, LRR and PYD domains-containing protein 3 SARS-CoV-2 SARS-coronavirus 2 S Spike E Envelope M Membrane N Nucleocapsid ACE2 Angiotensin-converting enzyme 2 BDK Bradykinin BDKRB1 or 2 Bradykinin receptor B1 or B2 ARDS Acute respiratory distress syndrome OEA Oleoylethanolamide PPAR-α Peroxisome proliferator-activated receptor-alpha NET Neutrophil extracellular trap MAPK p38 p38 mitogen-activated protein kinases CRS Cytokine release syndrome HAS2 HA-synthase-2 NOD Nucleotide-binding oligomerization domain ASC Caspase recruitment domain MCP-1 Monocyte chemoattractant protein 1 WHO World Health Organization PBF Percentage of body fat BMI Body mass index NWO Normal Weight Obesity IMDs Immunomodulating diets ALA Linolenic acid EPA Eicosapentaenoic acid DHA Docosahexaenoic acid SPMs Specialized pro-resolving mediators VDR Vitamin D receptor PGE2 Prostaglandin E2 COX-2 Cyclooxygenase-2 RDA Recommended Dietary Allowance DRI Dietary Recommendation Intake ROS Reactive oxygen species ERK Extracellular signal-regulated kinase JKN c-Jun N-terminal kinase AP-1 Activator protein-1 VRIs Viral respiratory infections EGCG Epigallocatechin-3-gallate SCFAs Short Chain Fatty Acids GPRs G-protein-coupled receptors DCs Dendritic cells Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Acknowledgements We thank Fondazione Umberto Veronesi for supporting Dr. Francesca Pivari with Post-Doctoral Fellowship 2020. The authors thank Fulvia Mariotti for the editorial and English language revisions. Authors’ contributions LDR and LS conceived and wrote the review; PG, FP, AA, CL, GC, EC, MGT, GC, GM, AMP, RD wrote the review. LDR, EC, GC drawn the figures. ADL had primary responsibility for the final content. All authors have read and agreed to the published version of the manuscript. All authors read and approved the final manuscript. Funding This research does not received external funding. Availability of data and materials Not applicable. Ethics approval and consent to participate Not applicable. Consent for publication Not applicable. Competing interests The authors declare no conflict of interest.