Analysis of faecal volatile organic compounds in preterm infants who develop necrotising enterocolitis: a pilot study.

OBJECTIVE: : To determine differences in the profiles of volatile organic compounds (VOCs) in faecal samples from preterm infants who develop necrotising enterocolitis (NEC) compared with non-NEC controls. MATERIALS AND METHODS: : Daily faecal samples from preterm infants were collected prospectively during an 8-month period from a level 3 regional neonatal intensive care unit. Six infants subsequently developed NEC and were matched with 7 non-NEC infants. Solid-phase microextraction and gas chromatography and mass spectrometry were used to extract and identify the VOCs from the headspace above the faecal samples taken before the onset of NEC and after the disease was diagnosed. Faecal samples at similar ages were also studied from the control infants. RESULTS: : Two hundred twenty-four different VOCs were extracted from 65 samples. Volatile organic compounds increased in number with age for non-NEC infants. In the days before and after the diagnosis of NEC a reduction in the number of VOCs extracted was observed. In addition, 4 specific esters present in controls-2-ethylhexyl acetic ester, decanoic acid ethyl ester, dodecanoic acid ethyl ester, and hexadecanoic acid ethyl ester-were consistently absent from all faecal samples in those infants who developed NEC in the 4 days before the onset of the disease. CONCLUSION: : This pilot study shows that VOC extraction from faeces may be used to identify infants that are at risk of developing NEC.

Volatile organic compounds from feces and their potential for diagnosis of gastrointestinal disease.

Little is known about the volatile organic compounds (VOCs) in feces and their potential health consequences. Patients and healthcare professionals have observed that feces often smell abnormal during gastrointestinal disease. The aim of this work was to define the volatiles emitted from the feces of healthy donors and patients with gastrointestinal disease. Our hypotheses were that i) VOCs would be shared in health; ii) VOCs would be constant in individuals; and iii) specific changes in VOCs would occur in disease. Volatile emissions in health were defined in a cohort and a longitudinal study. Subsequently, the pattern of volatiles found in the cohort study were compared to that found from patients with ulcerative colitis, Campylobacter jejuni, and Clostridium difficile. Volatiles from feces were collected by solid-phase microextraction and analyzed by gas chromatography/mass spectrometry. In the cohort study, 297 volatiles were identified. In all samples, ethanoic, butanoic, pentanoic acids, benzaldehyde, ethanal, carbon disulfide, dimethyldisulfide, acetone, 2-butanone, 2,3-butanedione, 6-methyl-5-hepten-2-one, indole, and 4-methylphenol were found. Forty-four compounds were shared by 80% of subjects. In the longitudinal study, 292 volatiles were identified, with some inter and intra subject variations in VOC concentrations with time. When compared to healthy donors, volatile patterns from feces of patients with ulcerative colitis, C. difficile, and C. jejuni were each significantly different. These findings could lead the way to the development of a rapid diagnostic device based on VOC detection.

Identification of Campylobacter infection in chickens from volatile faecal emissions.

Volatile organic compounds from chicken faeces were investigated as biomarkers for Campylobacter infection. Campylobacter are major poultry-borne zoonotic pathogens, colonizing the avian intestinal tract. Chicken faeces are the principal source of contamination of carcasses. Fresh faeces were collected on farm sites, and Campylobacter status established microbiologically. Volatile organic compounds were pre-concentrated from the headspace above 71 separate faecal samples using solid-phase microextraction and separated and identified by gas chromatography/mass spectrometry. A Campylobacter-specific profile was identified using six of the extracted volatile organic compounds. The model developed reliably identified the presence or absence of Campylobacter in >95% of chickens. The volatile biomarker identification approach for assessing avian infection is a novel approach to enhancing biosecurity in the poultry industry and should reduce the risk of disease transmission to humans.