Effects of melanin from Sepiella Maindroni ink (MSMI) on the intestinal Microbiome of mice

BACKGROUND: By the search for new natural compounds with beneficial health effects, cephalopod ink has been considered as an attempt to develop new drugs and functional foods, which is an especially active field in Asia, where cephalopods are a major fishery catch, for which ink sacs are a bi-product and where homeopathic medicine has deep roots. There is a demand to evaluate the safety and influence to the organism. The specific composition and relative abundance of the gut microbiota, which is potentially a major modulator of host metabolism, drives the interaction between functional foods and host health. We explore the effects of melanin from Sepiella Maindroni, most common cuttlefish in China, on the intestinal microbiome of mice. RESULTS: ICR mice were randomly divided four groups, which were normal group (S), low melanin dose group (D; 120 mg/kg), medium melanin dose group (Z; 240 mg/kg), and high melanin dose group (G; 480 mg/kg). Melanin was delivered for 28 consecutive days. Fecal samples were used to generate 7715 operational taxonomic units (OTUs) via high-throughput sequencing. There were significant shifts in relative abundance of the dominant taxa at the phylum, class, order, family, and genus levels following melanin treatment. CONCLUSIONS: MSMI had no significant effect on the structure of intestinal flora in mice. The main effect was in the proportion of dominant bacterial communities. The effect positively correlated with the dose. From a health point of view, the use of melanin does not cause intestinal flora disorder. Our results may have important implications for MSMI as functional food component and potential therapeutic for manipulating gut microbiota.