土壌や灰は消化をどのように助けますか？土や灰を食べると、人間も消化して人間を助けますか？もしそうなら、どの文化によって土壌や灰を食べていますか？
How does soil or ash help with digestions? Would eating soil and ash help humans with their digestion as well? If so, is eating soil or ash done by any culture?