The claim specifies that plant traces were identified by sequencing microscopic DNA fragments found in dust and fibers, rather than visible food remains. While the general theme of DNA analysis of dust/fibers is present in the context of the web search results, the specific phrasing distinguishing 'sequencing microscopic DNA fragments' from 'visible food remains' is not independently corroborated by multiple sources, making it difficult to confirm beyond the context provided by the initial search results.

The claim states that the DNA analysis found multiple plant species, with carrot and bread wheat being the most dominant. While the web search results confirm the identification of multiple species and highlight carrot and bread wheat, the specific quantification of them being the 'most dominant' is not independently corroborated by multiple sources.

The claim lists specific horticultural crops (peppers, tomatoes, potatoes, melons, cucumbers). While web search results mention tomatoes, peppers, and potatoes in the context of the study's findings, the specific grouping and inclusion of melons/cucumbers are derived from a single, comprehensive snippet referencing the study's findings, and this specific list is not corroborated by other independent sources.

The claim links the presence of New World crops (tomatoes, maize, peanuts) to contamination after 1492. While the web search results mention the presence of New World crops and the implication of post-1492 contamination, this specific conclusion is presented as a single narrative thread within the evidence provided, lacking corroboration from multiple independent sources.