npub1a8…y9zy0 on Nostr: The Evolution of Stomach Acidity and Its Relevance to the Human Microbiome "It is ...
The Evolution of Stomach Acidity and Its Relevance to the Human Microbiome
"It is interesting to note that humans, uniquely among the primates so far considered, appear to have stomach pH values more akin to those of carrion feeders than to those of most carnivores and omnivores.
In the absence of good data on the pH of other hominoids, it is difficult to predict when such an acidic environment evolved. Baboons (Papio spp) have been argued to exhibit the most human–like of feeding and foraging strategies in terms of eclectic omnivory, but their stomachs–while considered generally acidic (pH = 3.7)–do not exhibit the extremely low pH seen in modern humans (pH = 1.5).
One explanation for such acidity may be that carrion [decaying flesh of dead animals] feeding was more important in humans (and more generally hominin) evolution than currently considered to be the case (...).
Alternatively, in light of the number of fecal-oral pathogens that infect and kill humans, selection may have favored high stomach acidity, independent of diet, because of its role in pathogen prevention."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4519257/
"It is interesting to note that humans, uniquely among the primates so far considered, appear to have stomach pH values more akin to those of carrion feeders than to those of most carnivores and omnivores.
In the absence of good data on the pH of other hominoids, it is difficult to predict when such an acidic environment evolved. Baboons (Papio spp) have been argued to exhibit the most human–like of feeding and foraging strategies in terms of eclectic omnivory, but their stomachs–while considered generally acidic (pH = 3.7)–do not exhibit the extremely low pH seen in modern humans (pH = 1.5).
One explanation for such acidity may be that carrion [decaying flesh of dead animals] feeding was more important in humans (and more generally hominin) evolution than currently considered to be the case (...).
Alternatively, in light of the number of fecal-oral pathogens that infect and kill humans, selection may have favored high stomach acidity, independent of diet, because of its role in pathogen prevention."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4519257/