Microbial activities are dependent on background conditions

Taking the case of H. pylori and ulcer, Lynch et al., demonstrate how framing Koch’s postulate by an interventionist account clarifies the latter’s explanatory strength in proportionality with the weaknesses in specificity and stability due to the influence of background conditions. They suggest this approach as an efficient way to bypass the enigma of background conditions and microbial activity in the microbiome’s causal relations. However, it is the background conditions and the microbial interactions in the stomach that determine whether the presence of H. pylori results in an ulcer. I agree with their analysis of the problems and challenges with the microbiome causal explanation but argue that their suggested framework is insufficient without a proper understanding and inclusion of the background conditions and microbial interactions. The reductionist approach fits well within the model of causal explanation that centers on one causal entity. However, such a model is weak in specificity and is too broad because it does not address the factors of microbial activity and background conditions. I argue that for a better causal explanation with explanatory strength in specificity, it is essential to include the background conditions and microbial interactions. Furthermore, I argue that this inclusion changes the framework of the causal relations from looking for the causal entity to looking at the causal process