Saliva: Salivary Microbiota, Kissing and Dry Mouth


Published: 27 March 2018

‘The importance of saliva in our everyday activities and the medicinal properties it possesses are often taken for granted’ (Tiwari 2011).

Body Fluids...

Whilst it may not be the most pleasant or attractive health topic, it's clear that in order to provide evidence-based care, nurses and healthcare professionals need to know about the body fluids that they may come in contact with when providing face-to-face patient care.

This article provides an overview of some issues related to saliva.

Saliva: Did You Know?...

  • The amount and quality of a person's saliva can affect oral and other systematic health outcomes
  • Saliva is viewed differently depending on cultural and social context (e.g. some cultures think of saliva positively, and others negatively)
  • Every person's saliva is unique
  • Saliva contains important information like pathology and disease biomarkers
  • Saliva may be used as a diagnostic tool
  • Due to the ability to non-invasively attain saliva samples, it may be a more desirable resource for diagnostics and health monitoring activities
  • Radiotherapy to the head/neck region may cause a loss of salivary gland function and is linked to dry-mouth issues (xerostomia).

(Tiwari 2011)

Baby blowing bubbles

Saliva and Kissing

Kissing is, of course, a common interaction that involves the transfer of saliva.

Wlodarski and Dunbar (2013) studied the possible functions of kissing, and concluded that kissing's key purpose was not to increase arousal but to assess the suitability of a mate.

Kort et al. (2014) studied kissing behaviours and salivary microbiota.

The microbiota of the saliva appears to be more similar in couples than disconnected individuals (Kort et al. 2014). However, Kort et al. indicate that this higher similarity is likely due to a higher frequency of intimate kissing.

Interestingly, couples tested within an hour-and-a-half of a kiss or who had around nine or more kisses daily were more likely to share salivary microbiota (Kort et al. 2014).

Microbiology aside, Wlodarski and Dunbar maintain that partners kissing frequency remains a sign of relationship satisfaction (2013).

Saliva and Oral Health

Understanding oral bacteria is an important part of oral and dental health.

Harmful oral bacteria may lead to health issues such as potential disease spread and a risk of aspiration pneumonia (Better Health Channel 2014; Kikutani et al. 2014).

It was found in Kikutani et al.’s study that ‘(an) oral bacteria count of 108.5 colony-forming units/mL saliva in an elderly person requiring care was identified as a risk factor for pneumonia onset’ (2014).

Additionally, Whitmore and Lamont (2014) claim that ‘improved oral hygiene and treatment of periodontitismay be useful in limiting the development or spread of cancer.’

Evidently, there is a need for nurses and healthcare professionals to promote, deliver and train clients in correct and ongoing oral hygiene practices and check-ups.

Javaid et al. (2016) explain that saliva can be used for diagnostic testing due to its biomarkers, genetic matter and proteins.

Salivary testing is described as not only being relatively easy but also cost-efficient. It is apparent that increased research into this field, as well as validation and establishment of guidelines, may improve the use of salivary diagnostic tools (Javaid et al. 2016).

saliva mouth swab

Dry Mouth Syndrome

Some other interesting studies related to saliva include those by Furness et al. (2013) and Riley et al. (2017), which investigated the prevention of dry mouth.

Furness et al. stated that there was not enough evidence to conclude whether electrostimulation was effective for the prevention of dry mouth.

They also concluded that there was low-quality evidence that symptoms of dry mouth were no different between acupuncture or placebo treatment.

Yet, Furness et al. also conveyed that there was some low-quality evidence that acupuncture may increase saliva in small amounts for people with dry mouth post-radiotherapy (2013).

Riley et al. (2017) found in their study that the sensation of dry mouth may be prevented with the use of amifostine for participants undergoing head and neck radiotherapy.

This conclusion was made based on low-quality evidence and the effects were short- or medium-term (2017).

It was also found that the people who received amifostine were more likely to experience adverse effects including vomiting and low blood pressure (Riley et al. 2017), thereby emphasising that the use of amifostine needs to be cautioned and that a risks-versus-benefits analysis should occur.



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Madeline Gilkes View profile
Madeline Gilkes, CDE, RN, is a Fellow of the Australasian Society of Lifestyle Medicine. She focused her Master of Healthcare Leadership research project on health coaching for long-term weight loss in obese adults. Madeline has found a passion for preventative nursing. She has transitioned from leadership roles (CNS Gerontology & Education, Clinical Facilitator) in the acute/hospital setting to education management and primary healthcare. Madeline’s vision is to implement lifestyle medicine to prevent and treat chronic conditions. Her research proposal for her PhD involves Lifestyle Medicine for Type 2 Diabetes Mellitus. Madeline is a Credentialled Diabetes Educator (CDE) and primarily works in the academic role of Head of Nursing. Madeline’s philosophy focuses on using humanistic management, adult learning theories/evidence and self-efficacy theories and interventions to promote positive learning environments. In addition to her Master of Healthcare Leadership, Madeline has a Graduate Certificate in Diabetes Education & Management, Graduate Certificate in Adult & Vocational Education, Graduate Certificate of Aged Care Nursing, and a Bachelor of Nursing. She is working towards her PhD.