Koch’s postulates originally proposed a one microorganism–one disease approach to disease; however, it is now clear that many diseases of plants and animals are associated with changes in the taxonomic composition and function of the microbiome, and that health and disease are mediated by a dynamic interplay between host factors, environmental factors, the host microbiota and pathogenic microorganisms. Commensal microbes can become pathogenic under certain conditions, and disease can arise from complex polymicrobial infections. Although causation and correlation can be difficult to untangle, it is clear that the host microbiome plays a key role in resisting colonisation by pathogens across all host taxa, from plants to animals to humans. This offers exciting possibilities for manipulating microbiomes in order to reduce pathogenic infection in a range of contexts, including agriculture, wildlife and human health, through the use of probiotics, prebiotics and microbiome transplants, among other approaches.

A classic example of microbiome function is its role in nutrient assimilation in both plants and animals, but other less obvious roles are becoming more apparent, particularly in terms of driving infectious and non-infectious disease outcomes and influencing host behaviour. However, numerous biotic and abiotic factors influence the composition of these communities, and host microbiomes can be susceptible to environmental change. How microbial communities will be altered by, and mitigate, the rapid environmental change we can expect in the next few decades remain to be seen. That said, given the enormous range of functional diversity conferred by microbes, there is currently something of a revolution in microbial bioengineering and biotechnology in order to address real-world problems including human and wildlife disease and crop and biofuel production. All of these concepts are explored in further detail throughout the book.

TERMINOLOGY AND CULTURAL AND LEGAL CONTEXT

Aotearoa New Zealand is a common law jurisdiction, with a Parliament and legal system based on the British Westminster system of government, following colonisation in the 19th century. Māori are the indigenous people of Aotearoa and signatories to the Treaty of Waitangi, which Māori consider to allow them to retain self-governance rights and, in particular, Māori customary law.

Pre-colonial Māori communities were ‘inclusive of whakawāhine’ (a Māori term describing someone born with a male body who has a female gender identity). More recently takatāpui has been reclaimed as a term to describe gay, lesbian, bisexual and trans Māori.

Today Māori whakawāhine and tangata ira tane (a Māori term describing someone born with a female body who has a male gender identity) remain visible within takatāpui communities. A support network for Māori trans people (Tapatoru), based on the traditional concept of whānau or family, now exists. There are many predominantly Pākehā (European) or Tauiwi (non-Māori) networks.

New Zealand also has a large Pacific Island population, many of whom acknowledge males who take on traditional female social roles (such as fa'sfafine in Samoa and fakaleiti in Tonga). It is therefore not surprising that the people who made submissions to the New Zealand Human Rights Commission's Transgender Inquiry (see further at section 2.1 below) referred to themselves using a range of terms, including transgender, male-to-female (MtF) and female-to-male (FtM) transsexuals, cross-dressers, queens, intersex, androgynous, genderqueer, takatāpui, fa'sfafine, fakaleiti, whakawahine and tangata ira tane.

In this chapter, as in To Be Who I Am: Report of the Inquiry into Discrimination Experienced by Transgender People (the Report of the Transgender Inquiry), the term ‘trans’ will be used when it is necessary to use a generic term to describe all of the identities listed above. That is, to describe all those ‘who identify their gender in some way in opposition or outside the gender role which they are meant to fulfil as a result of their sex designation at birth.’

The focus of this chapter, as elsewhere in this book, is on the issues for trans people who wish to have their ‘nominated sex’ (the sex they self-identify with) recognised as their legal sex (for the purposes of official identity documentation).