We have lost touch with our wider microbiome 1 July, p 17 From Will Kemp, Wagait Beach, Northern Territory, Australia You suggest that industrialisation and diet may influence the human gut microbiome. Defecation would have returned gut microbes directly to the soil, rather than waste being carried away by modern sewerage systems. Views Your letters There is no easy way to tackle the obesity epidemic 15 July, p 32 From Ken Hill, London, UK Obesity is worrying ly omnipresent in some countries and is, in my opinion, unlikely to be significantly abated by the use of drugs. [Extracted from the article]