Fermented sausages as source of lactic acid bacteria for the gut microbiome

It is well-known that lactic acid bacteria (LAB) are critical during the production of fermented foods, and several strains are considered as probiotics, leading food industries to have increasing interest towards the exploitation of these microorganisms. Mediterranean countries are recognized for their several fermented foods, such as fermented sausages, cheeses and dairy products, and fermented vegetables. Despite this long-term food culture, it is not yet known the source of LAB in the gut microbiota of consumers. Indeed, the abilities of some microorganisms to be transferred through the food production chain, persist in the final product, and potentially colonize the human gut are still poorly understood. With the present study, we provide evidence at strain level, to support the hypothesis that LABs associated with fermented meats can be transferred to the human gut. Samples along the production chain of fermented sausages (feed, pigs’ fecal samples, pigs’ skin after scalding, pigs’ skin after gathering, meat butter, meat butter after 24 hours of fermentation, belt, stuffer, grinder, cutting table, and sample from the final product) were collected. After ripening 30 healthy omnivorous subjects were enrolled to perform an interventional study. The intervention consisted of consumption of 40g/day of fermented sausages for 1 week. Fecal samples were collected before and after the intervention. Samples were then subject to metagenomic and culture-based analysis The meta-omic approaches showed the presence of Latilactobacillus sakei in the gut of the participants after the consumption of the fermented sausage. The culture-dependent methods, in agreement with molecular analysis, showed the presence of Latictobacillus sakei, confirming the horizontal transfer.