Table 1.

Bacterial indicators used in this study and their respective growth conditions.

Bacterial Strain	Media for Cultivation	Growth Atmosphere	Temperature (°C)
Lactobacillus bulgaricus LMG6901 *	MRS	Anaerobic ******	37
Listeria innocua DPC3572 **	BHI ***	Aerobic	37
Fusobacterium nucleatum DPC6999	FAA/WCA ****	Anaerobic	37
Clostridioides difficile DPC6509	RCA/BHI *****	Anaerobic	37

* LMG = Belgian Co-ordinated Collections of Microorganisms. ** DPC = Teagasc Culture Collection *** BHI = Brain Heart Infusion (Sigma, London UK) **** FAA/WCA = Fastidious Anaerobic Agar/Wilkins Charlgreen Agar (LabM, Bury UK/ Sigma, London UK) ***** RCA = Reinforced Clostridial Agar (Sigma, London UK) ****** anaerobic conditions were achieved using an anaerobic chamber, except for L. bulgaricus, for which anaerobic jars and Anaerocult gas packs (Merck, Darmstadt, Germany) were used.