Paleogenomic insights into the red complex bacteria Tannerella forsythia in Pre-Hispanic and Colonial individuals from Mexico.

The 'red complex' is an aggregate of three oral bacteria (Tannerella forsythia, Porphyromonas gingivalis and Treponema denticola) responsible for severe clinical manifestation of periodontal disease. Here, we report the first direct evidence of ancient T.forsythia DNA in dentin and dental calculus samples from archaeological skeletal remains that span from the Pre-Hispanic to the Colonial period in Mexico. We recovered twelve partial ancient T. forsythia genomes and observed a distinct phylogenetic placement of samples, suggesting that the strains present in Pre-Hispanic individuals likely arrived with the first human migrations to the Americas and that new strains were introduced with the arrival of European and African populations in the sixteenth century. We also identified instances of the differential presence of genes between periods in the T. forsythia ancient genomes, with certain genes present in Pre-Hispanic individuals and absent in Colonial individuals, and vice versa. This study highlights the potential for studying ancient T. forsythia genomes to unveil past social interactions through analysis of disease transmission. Our results illustrate the long-standing relationship between this oral pathogen and its human host, while also unveiling key evidence to understand its evolutionary history in Pre-Hispanic and Colonial Mexico. This article is part of the theme issue 'Insights into health and disease from ancient biomolecules'.

Deep microbial community profiling along the fermentation process of pulque, a biocultural resource of Mexico.

The biggest non-tree perennial plant species endemic to Mexico were called metl in the Nahua culture; during colonial times, renamed with the Antillean word maguey. Carl von Linné finally renamed them as Agave, a Greek-Latin root word meaning admirable. Since pre-Columbian times, one of the major products obtained from some Agave species is the fermented beverage called pulque or octli. This beverage represents an ancient biotechnological development obtained by the natural fermentation of mead from such plants. Pulque played a central role in Mexican pre-Columbian cultures, while in recent times, there has been a renewed interest in it, due to its high content in nutrients and probiotics. In this study, we used massive sequencing of the 16S rRNA gene and the ribosomal internal transcribed spacer (ITS) to profile the pulque microbiome. We identified 2,855 bacteria operational taxonomic units (OTUs) and 1,494 fungi species in the pulque fermentation. Our results provide the most diverse catalog of microbes during pulque production reported so far. These findings allowed us to identify previously unidentified and core microbes resilient during pulque production, with the potential to be used as fermentation stage biomarkers. We confirmed previous reports of pulque microbes and discovered new ones like the bacteria Sphingomonas and Weisella. Among fungi we found that Saccharomyces cerevisiae was second to Candida zemplina in the studied pulque samples.