Fuente: "milk OR dairy products" Food Funct. 2026 Mar 30. doi: 10.1039/d5fo02980e. Online ahead of print.ABSTRACTDietary intake of N-nitroso compounds (NOCs) has been proposed as one of the mechanisms explaining the association between the consumption of red and processed meat and the increased risk of colorectal cancer (CRC). Endogenous NOCs can also be formed along the intestine, being finally excreted in feces. The intestinal microbiota could play a role in the formation of endogenous NOCs and their impact on health. In this work, the median fecal total and heme NOC concentrations of 46 volunteers were used to split the sample and analyze discriminant differences in the relative abundance of intestinal microbiota members and fecal short-chain fatty acids (SCFAs). PERMANOVA analysis further investigated associations between dietary factors and fecal NOCs with the microbiota. Finally, the association of intestinal microbiota with fecal NOCs in relation to the degree of mucosal damage was evaluated. Shifts in the relative abundance of Roseburia, Prevotella or Escherichia-Shigella according to fecal NOC concentrations were detected in stool samples. PERMANOVA analysis showed that these dietary precursors could also be related to the intestinal microbiota profile of volunteers and suggested that specific intestinal bacterial genera, rather than general microbial changes, were associated with fecal NOCs. Notably, the genera Escherichia-Shigella, Ruminococcus torques group, Subdoligranulum or Intestinibacter were found to be predictors of fecal NOC concentrations, depending on intestinal mucosal lesions. Furthermore, some of these genera were positively correlated with the intake of nitrate, nitrite and nitrosamines (NAs), precursor compounds of endogenous NOCs. Our study supports a link among specific intestinal microorganisms, fecal NOCs, and intestinal mucosal damage.PMID:41910534 | DOI:10.1039/d5fo02980e