Systematic Profiling of Growth Interactions in Human Gut Microbiome Species

Microbial interactions play a crucial role in shaping the composition and stability of the human gut microbiome. However, few studies have systematically investigated species-species growth interactions and the underlying mechanisms. In this study, researchers Buyanbadrakh et al. employed a comprehensive approach to investigate the growth interactions among 36 representative gut bacterial strains. Their findings reveal that when two species interact, the interactions are predominantly inhibitory in nature. To gain deeper insights into specific interactions, the authors focused on a positive interaction between Clostridium perfringens and Mediterraneibacter gnavus. They discovered that C. perfringens promotes the growth of M. gnavus through the release of extracellular vesicles. Furthermore, Veillonella parvula was identified as a species capable of modulating environmental pH, thereby enabling the growth of Parabacteroides merdae, a strain highly sensitive to acidic conditions. The authors found that V. parvula's pH-increasing effect is enhanced by guanine supplementation and persists in multi-species communities containing different pH-lowering strains from diverse bacterial phyla. Notably, V. parvula is commonly present in human gut microbiomes but is typically found at low levels. Given the spatial organization of bacteria in the gut, local pH modulation by V. parvula may support the growth of acid-sensitive strains. The comprehensive dataset and mechanistic insights presented here provide a valuable starting point for predicting microbiome composition by integrating growth interactions. However, it is essential to note that this research is intended for laboratory use only and should not be used for clinical or therapeutic purposes without further validation.