Humans have co-speciated with their gut-resident microbes, but it is difficult to infer features of our ancestral microbiome. Here, we examine the microbiome profile of 350 stool samples collected longitudinally for over a year from the Hadza hunter-gatherers of Tanzania. The data reveal annual cyclic reconfiguration of the microbiome, in which some taxa become undetectable only to reappear in a subsequent season. Comparison of the Hadza dataset with data collected from 18 populations in 16 countries with varying lifestyles reveals that gut community membership corresponds to modernization: Notably, the taxa within the Hadza that are the most seasonally volatile similarly differentiate industrialized and traditional populations. These data indicate that some dynamic lineages of microbes have decreased in prevalence and abundance in modernized populations.
We show that a citizen science, self-selected cohort shipping samples through the mail at room temperature recaptures many known microbiome results from clinically collected cohorts and reveals new ones. Of particular interest is integrating n = 1 study data with the population data, showing that the extent of microbiome change after events such as surgery can exceed differences between distinct environmental biomes, and the effect of diverse plants in the diet, which we confirm with untargeted metabolomics on hundreds of samples.
word count: 203 68 3 Main text word count: 3280 69 70 Abstract: Although much work has linked the human microbiome to specific phenotypes and 71 lifestyle variables, data from different projects have been challenging to integrate and the extent 72 of microbial and molecular diversity in human stool remains unknown. Using standardized 73 protocols from the Earth Microbiome Project and sample contributions from over 10,000 citizen-74 scientists, together with an open research network, we compare human microbiome specimens 75 primarily from the USA, UK, and Australia to one another and to environmental samples. Our 76 results show an unexpected range of beta-diversity in human stool microbiomes as compared to 77 environmental samples, demonstrate the utility of procedures for removing the effects of 78 overgrowth during room-temperature shipping for revealing phenotype correlations, uncover 79 new molecules and kinds of molecular communities in the human stool metabolome, and 80 examine emergent associations among the microbiome, metabolome, and the diversity of plants 81 that are consumed (rather than relying on reductive categorical variables such as veganism, 82 which have little or no explanatory power). We also demonstrate the utility of the living data 83 resource and cross-cohort comparison to confirm existing associations between the microbiome 84 and psychiatric illness, and to reveal the extent of microbiome change within one individual 85 during surgery, providing a paradigm for open microbiome research and education. 86 87Importance: We show that a citizen-science, self-selected cohort shipping samples through the 88 mail at room temperature recaptures many known microbiome results from clinically collected 89 cohorts and reveals new ones. Of particular interest is integrating n=1 study data with the 90 population data, showing that the extent of microbiome change after events such as surgery can 91 4 exceed differences between distinct environmental biomes, and the effect of diverse plants in the 92 diet which we confirm with untargeted metabolomics on hundreds of samples. 93 94 Introduction 95The human microbiome plays a fundamental role in human health and disease. While 96 many studies link microbiome composition to phenotypes, we lack understanding of the 97 boundaries of bacterial diversity within the human population, and the relative importance of 98 lifestyle, health conditions, and diet, to underpin precision medicine or to educate the broader 99 community about this key aspect of human health. 100 We launched the American Gut Project (AGP; http://americangut.org) in November of 101 2012 as a collaboration between the Earth Microbiome Project (EMP) (1) and the Human Food 102 Project (HFP; http://humanfoodproject.com/) to discover the kinds of microbes and microbiomes 103 "in the wild" via a self-selected citizen-scientist cohort. The EMP is tasked with characterizing 104 the global microbial taxonomic and functional diversity, and the HFP is focused on 105 understanding microbial diversity a...
The composition of the gut microbiome in industrialized populations differs from those living traditional lifestyles. However, it has been difficult to separate the contributions of human genetic and geographic factors from lifestyle. Whether shifts away from the foraging lifestyle that characterize much of humanity’s past influence the gut microbiome, and to what degree, remains unclear. Here, we characterize the stool bacterial composition of four Himalayan populations to investigate how the gut community changes in response to shifts in traditional human lifestyles. These groups led seminomadic hunting–gathering lifestyles until transitioning to varying levels of agricultural dependence upon farming. The Tharu began farming 250–300 years ago, the Raute and Raji transitioned 30–40 years ago, and the Chepang retain many aspects of a foraging lifestyle. We assess the contributions of dietary and environmental factors on their gut-associated microbes and find that differences in the lifestyles of Himalayan foragers and farmers are strongly correlated with microbial community variation. Furthermore, the gut microbiomes of all four traditional Himalayan populations are distinct from that of the Americans, indicating that industrialization may further exacerbate differences in the gut community. The Chepang foragers harbor an elevated abundance of taxa associated with foragers around the world. Conversely, the gut microbiomes of the populations that have transitioned to farming are more similar to those of Americans, with agricultural dependence and several associated lifestyle and environmental factors correlating with the extent of microbiome divergence from the foraging population. The gut microbiomes of Raute and Raji reveal an intermediate state between the Chepang and Tharu, indicating that divergence from a stereotypical foraging microbiome can occur within a single generation. Our results also show that environmental factors such as drinking water source and solid cooking fuel are significantly associated with the gut microbiome. Despite the pronounced differences in gut bacterial composition across populations, we found little differences in alpha diversity across lifestyles. These findings in genetically similar populations living in the same geographical region establish the key role of lifestyle in determining human gut microbiome composition and point to the next challenging steps of determining how large-scale gut microbiome reconfiguration impacts human biology.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.