statistics from other independent studies 13,17,18 , we identify novel host-microbiota interactions. Furthermore, we explore the impact of potential confounding factors in modulating these genetic effects and identify potential diet-dependent host-microbiota interactions. We further assess the potential causal relationships between the gut microbiome and dietary habits, biomarkers and disease using Mendelian randomization (MR). Finally, we carry out a power analysis showing how microbiome studies, even at the current sample size, are underpowered to reveal the complex genetic architecture by which host genetics regulates the gut microbiome. ResultsGenome-wide associations with bacterial taxa and pathways. We investigated 5.5 million common (minor allele frequency (MAF) > 0.05) genetic variants on all autosomes and the X chromosome using linear mixed models 19 to test their association with 207 taxa and 205 bacterial pathways in 7,738 individuals from the DMP cohort (Methods and Supplementary Table 1) 19 . There was no evidence for test statistic inflation (median genomic lambda 1.002 (range, 0.75-1.03) for taxa and 1.004 (range, 0.87-1.04) for pathways). We identified 37 single nucleotide polymorphism (SNP)trait associations at 24 independent loci at a genome-wide P value threshold of 5 × 10 −8 (Fig. 1 and Supplementary Table 2). Genetic variants at two loci passed the more stringent study-wide threshold of 1.89 × 10 −10 that accounts for the number of independent tests performed (Methods).The strongest signal was seen for rs182549 located in an intron of MCM6, a perfect proxy of rs4988235 (r 2 = 1, 1000 Genomes Project European populations), one of the variants known to regulate the LCT gene and responsible for lactase persistence in adults (ClinVar accession RCV000008124). The T allele of rs182549, which confers lactase persistence through a dominant model of inheritance, was found to be associated with decreased abundances of the species Bifidobacterium adolescentis (P = 7.6 × 10 −14 ) and Bifidobacterium longum (P = 3.2 × 10 −08 ), as well as decreased abundances of higher-level taxa (Supplementary Table 2 (ref. 5 )). Associations at this locus were also seen for other taxa of the same genus but at lower levels of significance (Bifidobacterium catenulatum, P = 3.9 × 10 −5 ) and for species of the Collinsella genus (Extended Data Fig. 1). The genetic association at the LCT locus has been previously described, albeit only at the genus level, in Dutch, UK and US cohorts 6,8,14 , as well as in a recent large-scale meta-analysis 13 .The second locus that passed study-wide significance consisted of genetic variants near the ABO gene. ABO encodes the BGAT protein, a histo-blood group ABO system transferase. Associations found at this locus include species Bifidobacterium bifidum (rs8176645, p = 5.5 × 10 −15 ) and Collinsella aerofaciens (rs550057, P = 2.0 × 10 −8 , r 2 = 0.59 with rs8176645 in 1000 Genomes Project Europeans) and higher-order taxa (rs550057, genus Collinsella, P = 9.3 × 10 −11 ; family Coriobacteriac...

SummaryBiobanks are being established across the world to understand the genetic, environmental, and epidemiological basis of human diseases with the goal of better prevention and treatments. Genome-wide association studies (GWAS) have been very successful at mapping genomic loci for a wide range of human diseases and traits, but in general, lack appropriate representation of diverse ancestries - with most biobanks and preceding GWAS studies composed of individuals of European ancestries. Here, we introduce the Global Biobank Meta-analysis Initiative (GBMI) -- a collaborative network of 19 biobanks from 4 continents representing more than 2.1 million consented individuals with genetic data linked to electronic health records. GBMI meta-analyzes summary statistics from GWAS generated using harmonized genotypes and phenotypes from member biobanks. GBMI brings together results from GWAS analysis across 6 main ancestry groups: approximately 33,000 of African ancestry either from Africa or from admixed-ancestry diaspora (AFR), 18,000 admixed American (AMR), 31,000 Central and South Asian (CSA), 341,000 East Asian (EAS), 1.4 million European (EUR), and 1,600 Middle Eastern (MID) individuals. In this flagship project, we generated GWASs from across 14 exemplar diseases and endpoints, including both common and less prevalent diseases that were previously understudied. Using the genetic association results, we validate that GWASs conducted in biobanks worldwide can be successfully integrated despite heterogeneity in case definitions, recruitment strategies, and baseline characteristics between biobanks. We demonstrate the value of this collaborative effort to improve GWAS power for diseases, increase representation, benefit understudied diseases, and improve risk prediction while also enabling the nomination of disease genes and drug candidates by incorporating gene and protein expression data and providing insight into the underlying biology of the studied traits.

PurposeThe Lifelines COVID-19 cohort was set up to assess the psychological and societal impacts of the COVID-19 pandemic and investigate potential risk factors for COVID-19 within the Lifelines prospective population cohort.ParticipantsParticipants were recruited from the 140 000 eligible participants of Lifelines and the Lifelines NEXT birth cohort, who are all residents of the three northern provinces of the Netherlands. Participants filled out detailed questionnaires about their physical and mental health and experiences on a weekly basis starting in late March 2020, and the cohort consists of everyone who filled in at least one questionnaire in the first 8 weeks of the project.Findings to date>71 000 unique participants responded to the questionnaires at least once during the first 8 weeks, with >22 000 participants responding to seven questionnaires. Compiled questionnaire results are continuously updated and shared with the public through the Corona Barometer website. Early results included a clear signal that younger people living alone were experiencing greater levels of loneliness due to lockdown, and subsequent results showed the easing of anxiety as lockdown was eased in June 2020.Future plansQuestionnaires were sent on a (bi)weekly basis starting in March 2020 and on a monthly basis starting July 2020, with plans for new questionnaire rounds to continue through 2020 and early 2021. Questionnaire frequency can be increased again for subsequent waves of infections. Cohort data will be used to address how the COVID-19 pandemic developed in the northern provinces of the Netherlands, which environmental and genetic risk factors predict disease susceptibility and severity and the psychological and societal impacts of the crisis. Cohort data are linked to the extensive health, lifestyle and sociodemographic data held for these participants by Lifelines, a 30-year project that started in 2006, and to data about participants held in national databases.