Microbiome research reveals declining bacterial diversity and presence of giant bacteria

Recent scientific studies have revealed significant insights into the human gut microbiome, highlighting both a loss of microbial diversity in modern societies and the potential presence of giant bacteria.

Researchers from Stanford University identified 1,200 shared microbial species between the Tsimane people of Bolivia and the Hadza of Tanzania. Despite their different diets and environments, these two traditional groups share a high degree of microbial similarity. However, approximately 60 percent of the bacterial strains found in these groups are rare or entirely absent in industrialized, urbanized populations. For instance, a previous study noted that Californians host an average of 277 different microbial species, compared to 730 in the Hadza.

Separately, researchers at the Technical University of Berlin analyzed DNA sequences from over 600,000 microbiome samples worldwide. They found evidence of DNA from the Epulopiscium genus—known as giant bacteria that can grow up to 600 micrometers—within human samples. While these bacteria typically make up only 1-2 percent of identified sequences, they can reach up to 20 percent in some cases. While their exact role in humans remains unknown, they are associated with digestive enzyme function in fish, and their presence in humans may serve as an indicator of gut flora imbalance.