In 2004, the American Civil Liberties Union ("ACLU") threatened to sue the city of Redlands, California, if it did not remove a small cross from its city seal.' The cross represented the city's religious heritage and its history as a city of churches. Instead of facing the possibility of litigation and the more daunting risk of losing in court and being forced to pay the ACLU's attorneys' fees in addition to its own, the Redlands City Council agreed to change the seal. The City of Redlands not only could ill afford the risk of paying the ACLU's attorneys' fees; it also had insufficient municipal funds to replace the seal. Therefore, the city had to improvise. Blue tape covered the cross on many city vehicles, and some city employees used electric drills to "obliterate" the cross from their badges. After its success in Redlands, the ACLU turned its attention to the Los Angeles County seal, which contained a small cross symbolizing the Spanish missions that played an integral role in the county's history. One newspaper columnist observed, "The cross was about one-sixth the size of a not-very-big image of a cow tucked away on the lower right segment of the seal, and maybe a hundredth of the size of a pagan god (Pomona, goddess of fruit) who dominated the seal." The county's attorneys advised that a loss in court would be costly-the county would be responsible not only for the cost of changing the seal and its own legal fees, but also for the ACLU's legal fees. In what was an unpopular decision, the county supervisors voted to redesign the seal. The transition to the new seal is costing the county around $1 million and entails replacing the seal on approximately 90,000 uniforms, 12,000 vehicles, and 6,000 buildings. Events similar to these are taking place around the country. Some Americans view these events as victories over governments endorsing a particular religion in violation of the First Amendment's Establishment Clause and attempting to force religion upon their citizens. Others believe that these events are ...
[Background]: The gut microbiome and iron status are known to play a role in the pathophysiology of non-alcoholic fatty liver disease (NAFLD), although their complex interaction remains unclear. ; [Results]: Here, we applied an integrative systems medicine approach (faecal metagenomics, plasma and urine metabolomics, hepatic transcriptomics) in 2 well-characterised human cohorts of subjects with obesity (discovery n = 49 and validation n = 628) and an independent cohort formed by both individuals with and without obesity (n = 130), combined with in vitro and animal models. Serum ferritin levels, as a markers of liver iron stores, were positively associated with liver fat accumulation in parallel with lower gut microbial gene richness, composition and functionality. Specifically, ferritin had strong negative associations with the Pasteurellaceae, Leuconostocaceae and Micrococcaea families. It also had consistent negative associations with several Veillonella, Bifidobacterium and Lactobacillus species, but positive associations with Bacteroides and Prevotella spp. Notably, the ferritin-associated bacterial families had a strong correlation with iron-related liver genes. In addition, several bacterial functions related to iron metabolism (transport, chelation, heme and siderophore biosynthesis) and NAFLD (fatty acid and glutathione biosynthesis) were also associated with the host serum ferritin levels. This iron-related microbiome signature was linked to a transcriptomic and metabolomic signature associated to the degree of liver fat accumulation through hepatic glucose metabolism. In particular, we found a consistent association among serum ferritin, Pasteurellaceae and Micrococcacea families, bacterial functions involved in histidine transport, the host circulating histidine levels and the liver expression of GYS2 and SEC24B. Serum ferritin was also related to bacterial glycine transporters, the host glycine serum levels and the liver expression of glycine transporters. The transcriptomic findings were replicated in human primary hepatocytes, where iron supplementation also led to triglycerides accumulation and induced the expression of lipid and iron metabolism genes in synergy with palmitic acid. We further explored the direct impact of the microbiome on iron metabolism and liver fact accumulation through transplantation of faecal microbiota into recipient's mice. In line with the results in humans, transplantation from 'high ferritin donors' resulted in alterations in several genes related to iron metabolism and fatty acid accumulation in recipient's mice. ; [Conclusions]: Altogether, a significant interplay among the gut microbiome, iron status and liver fat accumulation is revealed, with potential significance for target therapies. ; This work was supported by EU-FP7 FLORINASH (Health-F2-2009-241913) to R.B., M.F., J.M.F.R., E.H. and J.K.N. Infrastructure support was provided by the National Institute for Health Research (NIHR) Imperial Biomedical Research Centre (BRC). L.H. was in receipt of an MRC Intermediate Research Fellowship in Data Science (grant number MR/L01632X/1, UK Med-Bio). This work was also partly supported by funding to M.-E.D. (EU METACARDIS under agreement HEALTH-F4-2012-305312, Neuron II under agreement 291840 and the MRC MR/M501797/1) and by grants from the French National Research Agency (ANR-10-LABX-46 [European Genomics Institute for Diabetes]), from the National Center for Precision Diabetic Medicine – PreciDIAB, which is jointly supported by the French National Agency for Research (ANR-18-IBHU-0001), by the European Union (FEDER), by the Hauts-de-France Regional Council (Agreement 20001891/NP0025517) and by the European Metropolis of Lille (MEL, Agreement 2019_ESR_11) and by Isite ULNE (R-002-20-TALENT-DUMAS), also jointly funded by ANR (ANR-16-IDEX-0004-ULNE) the Hauts-de-France Regional Council (Agreement 20002045) and by the European Metropolis of Lille (MEL). J.M.-P. is funded by the Miguel Servet Program from the Instituto de Salud Carlos III (ISCIII CP18/00009), co-funded by the European Social Fund 'Investing in your future'. María Arnoriaga Rodríguez is funded by a predoctoral Río Hortega contract (CM19/00190, co-funded by European Social Fund 'Investing in your future') from the Instituto de Salud Carlos III, Spain. This work was supported by grants to AM from the Spanish Ministry of Science and Innovation (PID2019-105969GB-I00) and Generalitat Valenciana (project Prometeo/2018/133). ; Peer reviewed