Oral microbiota changes in patients under enteral feeding through endoscopic gastrostomy

Abstract

Introduction: Endoscopic gastrostomy (PEG) is the gold standard for long-term enteral feeding for patients who lose the ability to swallow, which deprives the passage of food and liquids through the mouth. Normal oral microbiota is known to perform functions of protection and maintenance of oral and systemic health. Therefore, oral dysbiosis, promoted by absence of oral feeding, may create favourable conditions for microorganisms with pathological potential [1]. This study aims to evaluate changes in the oral microbiota of patients under PEG-feeding.

Materials and methods: For this observational study, a convenience sample group was recruited at the Artificial Feeding Outpatient Clinic of the Hospital Garcia de Orta. Subjects submitted to antimicrobial therapy were excluded. Informed consent of all participants was obtained. Oral Samples were collected, with a sterile swab, from the back of the tongue immediately before gastrostomy and after one month exclusive PEG-feeding. After collection, sample were suspended in sterile saline solution and inoculated on Blood, Chapman, MacConkey and BrillanceCandida™ agar media.

Results: The studied group included 17 patients, aged 64 ± 10 years, that underwent PEG due to head or neck cancer (76%) or neurological disorders (24%). After a month of absence of oral feeding, rates of yeast or lactose fermenting gram-negative organisms colonization were similar. We found a change from 76 to 88% patients colonized with candida species, in particular C. albicans and C. glabrata, and 24% to 29% patients colonized with lactose fermenting gram-negative bacteria. Differently, lactose non-fermenting gram-negative or Staphylococcus species showed lower occurrences, decreasing from 53 to 24% patients and from 59% to 24% patients respectively. Less than 30% of the subjects showed increased numbers of colony forming units but, from these, only two patients have increased microbiological load in all media tested. On the contrary, a higher rate of isolation of beta haemolytic bacteria, from 53 to 94% patients, was found after one month exclusive PEG-feeding.

Discussion and conclusions: The results from this group of patients on one month enteral feeding showed a global reduction both on isolation rates and microbial load of microorganism cultured from oral cavity. Noteworthy, was the higher rate of isolation of beta haemolytic bacteria. Although early studies reported significant bacterial overgrowth, those were focused on patients on prolonged enteral nutrition [2,3]. Thereby, a further follow-up of this group is needed.

Acknowledgements

The authors acknowledge funding from Egas Moniz – Cooperativa de Ensino.