5 letter words:
bitos7,
obits7,
4 letter words:
bios6,
bist6,
bito6,
bits6,
bois6,
bots6,
obis6,
obit6,
stob6,
3 letter words:
bio5,
bis5,
bit5,
boi5,
bos5,
bot5,
obi5,
obs5,
sib5,
sob5,
ios3,
iso3,
its3,
sit3,
sot3,
tis3,
2 letter words:
bi4,
bo4,
ob4,
io2,
is2,
it2,
oi2,
os2,
si2,
so2,
st2,
ti2,
to2,