Nutritional composition, heavy metal content and effect on the human gut microbiota of , an underutilized crustacean from the Atlantic coast.

In this study, an undervalued marine crustacean () was characterized in terms of nutritional and heavy metal composition and its potential to affect human gut microbiota. Nutritional analysis of this crustacean revealed that it complies with the criteria established in European legislation to include nutritional claims in their labeling, such as "source of fiber," "low in fat," "low in sugars" and "high in protein." The analysis of the heavy metal content did not reveal any risk derived from the presence of Cd, Hg, or Pb, whereas essential metals contained in 100 g exceeded the minimum daily requirements recommended in Europe for Zn (19.78 mg/kg), Cu (2.28 mg/kg), and Fe (32.96 mg/kg). Using an system, the effect of on the human colonic microbiota shows some beneficial effects, such as fermentation-maintained populations of or , did not increase Firmicutes counts, decreased the Firmicutes/Bacteroidetes ratio, and stimulated 11 metabolic pathways with respect to baseline. These results are unusual in a high protein content-food. However, negative effects were also found in gut microbiota relative proportions, such as an increase in the Proteobacteria and especially some opportunistic bacteria from this , probably due to the antimicrobial effect of chitin on other groups more sensitive to its effect. This work shows for the first time the effect of on human colonic microbiota using and system. The presence of chitin in its composition could provide some beneficial effects by modulating the microbiota, but as is a high-protein food, more studies should be carried out showing these benefits.