Detection of caecal indigenous bacteria susceptible to low-mineral- and high-salt-diet in ICR mice

Both deficiency and overdose of minerals and salts have an undesirable effect on health. Changes in dietary composition affect the gut microbiome immediately. To clarify the presence of gut indigenous bacteria susceptible to minerals and/or salts (MS-SIB), ICR mice were fed a diet containing 3.5% (w/w) mineral mix (Control), 1% mineral mix (LM), or 3.5% mineral mix and 4% NaCl (HS) for 14 days. Compared with the Control group, drinking water consumption of HS group was 2.5 times higher than any of the other groups. Body weight gain was 55% lower with HS. The caecal microbiome was examined by 16S rDNA(V4) amplicon sequencing. At phylum level, ratio of Firmicutes was lower in mice with HS. At operational taxonomic unit level, Desulfovibrionaceaer-, Turicibacter sanguinis- and Clostridium disporicum-like bacteria were dominants in Control group. Among them T. sanguinis- and C. disporicum-like bacteria were suppressed drastically by HS. Eubacterium coprostanoligenes- and Lactobacillus murinus-like bacteria tended to be high with LM and HS, respectively. The effects of ingested minerals and/or salts on the host may also involve interactions between the host health and the gut microbe. Detection and isolation of human MS-SIB is needed to clarify the interaction.