Hmmmm .... I think the serving size got lost in translation from the original Italian . Other imported brands of passata, including Emma "organic", range from 25 to 40 calories per 125 ml serving, depending on thickness (ie, more watery sauce will have lower cals/carbs). This one shows only 5 calories per serve , which makes me think it's per fl. oz .. or possibly even per Tablespoon (15 ml).

Here's the nutrition data for Emma brand "organic" passata (strained tomatoes, salt) ...

Per 125 ml
Calories: 25
Fat: 0 g
Sodium: 160 mg
Carbohydrate: 5 g
..... Fibre: 1 g
..... Sugars: 4 g
Protein: 1 g

Every other brand of passata di pomodoro that I've seen, imported or domestic, averages 5 or 6 net carbs per 125 ml. I can't imagine the Emma non-organic brand being so much lower unless the serving size is also lower.