It is believed raw egg in mayonnaise made at the Silo bakery in Kingston is to blame for the outbreak.
ACT Health has confirmed 13 people have been affected by salmonella bacteria.
Five were hospitalised with dehydration after suffering severe vomiting and diarrhoea.
The bakery has been closed by health authorities until the source is confirmed.
Silo co-owner Leanne Gray says she is scrupulous about food hygiene and is perplexed by the outbreak.
“Until those sub-species [lab] results come back the information is not conclusive,” she said.
“But I do understand the Health Department have to take actions if they have suspicions and we have nothing to hide.”
Chief Health Officer Paul Kelly says nearly all those who contracted the salmonella bacteria had eaten a roll containing chicken and mayonnaise.
“Both chicken and raw eggs are possible sources of this particular bug,” he said.
Ms Gray says everything is being done at the business to track the source of the outbreak.