Neanderthals had different types of bacteria in their mouths compared to modern humans and chimpanzees, with varying amounts of Gram-positive and Gram-negative bacteria, which reflects differences in...
Mechanism
Synthesis from 1 study
What Neanderthals ate shaped the bacteria in their mouths over thousands of years. Meat eaters ended up with different bacteria than plant eaters, and these differences stuck around because the food they ate never changed much. This created a unique microbial fingerprint that set them apart from...
Most probable mechanism
What a person eats changes the kinds of bacteria that live in their mouth. Meat-heavy diets feed bacteria that break down proteins and fats, making those bacteria more common. Plant-heavy diets feed bacteria that break down sugars and fibers, making those bacteria more common instead. Over time, these food choices shape the whole bacterial community in the mouth, leading to stable differences in which types of bacteria dominate. These differences are passed down through generations and become part of the population's microbial signature.
Consumption of animal protein and fat provides amino acids and lipids that serve as preferred energy sources for proteolytic and lipid-metabolizing bacteria, which are predominantly Gram-positive.
Consumption of plant-derived carbohydrates, polysaccharides, and fibers provides substrates that favor fermentative and cellulolytic bacteria, which are predominantly Gram-negative.
Nutrient-specific selection pressures in the dental plaque biofilm cause long-term dominance of bacterial taxa adapted to the prevailing dietary inputs, leading to distinct phylum-level compositions.
Stable colonization by specific microbial strains, such as Methanobrevibacter oralis, persists across generations due to environmental consistency and vertical transmission, reinforcing population-level microbial signatures.
Less supported by current evidence, but not ruled out
Ingesting certain plants with natural antimicrobial properties can reduce specific bacteria in the mouth, shifting the balance of microbial communities. This may temporarily suppress some species and allow others to thrive, contributing to microbial differences beyond diet alone.
Ingestion of plant materials containing salicylic acid or fungal antibiotics introduces bioactive compounds into the oral cavity.
These compounds inhibit or kill specific bacterial strains, reducing their abundance and altering the competitive dynamics within the oral biofilm.
Repeated exposure to such compounds over time may lead to persistent shifts in microbial composition, even in the absence of dietary change.
Evidence from Studies
Supporting (1)
Community contributions welcome
Neanderthal behaviour, diet, and disease inferred from ancient DNA in dental calculus
Contradicting (0)
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