Competition for shared resources increases dependence on initial population size during coalescence of gut microbial communities

• 成果类型: Article
• 署名作者: Goldman, Doran A.; Xue, Katherine S.; Parrott, Autumn B.; Lopez, Jamie A.; Vila, Jean C. C.; Jeeda, Rashi R.; Franzese, Lauryn R.; Porter, Rachel L.; Gray, Ira J.; DeFelice, Brian C.; Petrov, Dmitri A.; Good, Benjamin H.; Relman, David A.; Huang, Kerwyn Casey
• 署名单位: Stanford University; Stanford University; Stanford University; Stanford University; California Institute of Technology; Stanford University; Chan Zuckerberg Initiative (CZI); Stanford University; US Department of Veterans Affairs; Veterans Health Administration (VHA); VA Palo Alto Health Care System
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10367
• DOI: 10.1073/pnas.2322440122
• 发表日期: 2025-03-18
• 关键词: propagule pressure; invasions; DYNAMICS; coexistence; probiotics; EVOLUTION; FRAMEWORK; success; niches

摘要

The long-term success of introduced populations depends on both their initial size and ability to compete against existing residents, but it remains unclear how these factors collectively shape colonization dynamics. Here, we investigate how initial population (propagule) size shapes the outcome of community coalescence by systematically mixing eight pairs of in vitro microbial communities at ratios that vary over six orders of magnitude, and we compare our results to neutral ecological theory. Although the composition of the resulting cocultures deviated substantially from neutral expectations, each coculture contained species whose relative abundance depended on propagule size even after similar to 40 generations of growth. Using a consumer-resource model, we show that this dose-dependent colonization can arise when resident and introduced species have high niche overlap and consume shared resources at similar rates. Strain isolates displayed longer-lasting dose dependence when introduced into diverse communities than in pairwise cocultures, consistent with our model's prediction that propagule size should have larger, more persistent effects in diverse communities. Our model also successfully predicted that species with similar resource-utilization profiles, as inferred from growth in spent media and untargeted metabolomics, would show stronger dose dependence in pairwise coculture. This work demonstrates that transient, dose-dependent colonization dynamics can emerge from resource competition and exert long-term effects on the outcomes of community coalescence.